Top Flite Stinson Reliant Giant Scale on Electric [Archive]

ramovan

Dec 07, 2008, 06:26 PM

Welcome everyone,

For my winter project I wanted to build a giant scale electric plane and I've always loved the unique looks and reported flying characteristics of the Stinson Reliant. I chose the Top Flite 1/5th scale Stinson Reliant kit. As far as I know no one makes an ARF of the Reliant in this size so it's going to be a 6 month project for me - since I only get an hour or two most nights to work on it.

I have seen others electrify this plane in magazine articles which will be a good reference point, but I've still rarely seen this airplane on electric power. I'm not going to get too detailed in this build log as far as the building process since others have already done this in gas versions. I'm more interested in the discussion of the main components of the plane, the electric power system, and all the other electronics used to complete the build.

I encourage everyone to chime in with your thoughts and suggestions. I want to draw on the experience of other modelers, while hopefully providing some helpful information to anyone interested in building this model as an electric.

My target flying weight in electric is 20lbs, although I suspect I'll end up closer to 22lbs depending on the covering I use.

Here are the airplanes specs and stock photos from Top Flite
Wingspan: 100.5 in (2550 mm)
Wing Area: 1487 in² (95.9 dm²)
Weight: 16-25 lb (7260-11340 g)
Wing Loading: 24.8-38.7 oz/ft² (76-118 g/dm²)
Fuselage Length: 67.8 in (1720 mm)
Requires: 4-5 channel radio with 6-8 servos, 2-stroke 1.08-1.99 cu in (17.5-32.5 cc), 4-stroke 1.2-1.6 cu in (19.5-26), or 25-35 cc (1.5-2.0 cu in) gasoline engine, glow fuel, glow starter and support equipment

http://home.comcast.net/~ramovan/images/Stinson/ltopa0310.jpg
http://home.comcast.net/~ramovan/images/Stinson/a-topa0310.jpghttp://home.comcast.net/~ramovan/images/Stinson/topa0310a.jpg

Full Details here - http://www.top-flite.com/airplanes/topa0310.html

ramovan

Dec 07, 2008, 06:50 PM

For the power I'll be using a Scorpion 55mm motor which are due to be released sometime in December 2008. It's going to be a while before I'm ready for the motor as there is a ton of building to do. The 55mm motors are going to be available in 3 new physical sizes, each of which will have at least two Kv models to choose from - 7 models in all. I will discuss the exact motor selection later in more detail once the motors and full specs are released.

http://home.comcast.net/~ramovan/images/Stinson/55mm.jpg

For the ESC I plan to use the new Scorpion 12S controllers that will be coming out just before the 55mm motors are available. These will be available in 90A and 130A models. I'll choose which model I need after I know which motor I'm going to run. As with all the Scorpion ESCs these come with the wireless programming which is a pretty cool feature.

http://home.comcast.net/~ramovan/images/Stinson/250ESC1.jpg

More detail is available on the Scorpion webpage
http://www.scorpionsystem.com/

ramovan

Dec 07, 2008, 07:10 PM

For a battery I'll need either a 10 or a 12 cell lipo depending on the motor and prop size I select. I would like this to be about 8000mah for scale flights up to 20 minutes. This is by far the most expensive component of the airplane so I really need help making a careful decision. I plan to connect two 5 or 6-cell packs in series inside the plane to get the 10 to 12-cells needed. I would like to avoiding using 4 packs to get to 8000mah but with very few manufacturers making batteries this large my choices are limited - so I'm open to that option. Keeping my packs below 6-cells each will ensure I won't need to buy a new charger.

http://home.comcast.net/~ramovan/images/Stinson/LIPOtheory.jpg

ramovan

Dec 07, 2008, 07:54 PM

For guidance I'll be using a Spektrum DX7 transmitter and AR7000 receiver. This seems to be the best choice for me, although the AR9000 would be great (but expensive). The Stinson needs all 7 channels since I'll be using the optional flaps of course.

http://home.comcast.net/~ramovan/images/Stinson/SPM2710-450-crop2.jpghttp://home.comcast.net/~ramovan/images/Stinson/SPM6070-200-crop.jpg

ramovan

Dec 07, 2008, 08:09 PM

For servos I've decided on Hyperion DS20-UMD digital servos. These metal-gear ball bearing servos provide 193oz of torque @ 6v which is just above the recommended torque range. The Stinson needs good servos and I like these in particular because they offer the precisoin of digital and the programmable options I plan to take advantage of. IE: I'll be programming slower speeds for the flaps so they have more realistic movement without the need for a servo slow device. The Stinson needs 7 servos - 2 ailerons, 2 flaps, 2 elevators, and 1 rudder. These servos should work well in all these areas, since I won't need fast servo speeds on this large scale flying airplane.

http://home.comcast.net/~ramovan/images/Stinson/HP-DS20-XX-L-crop.jpg http://home.comcast.net/~ramovan/images/Stinson/HP-DS20-FMD-2-L-crop.jpg

ramovan

Dec 07, 2008, 08:22 PM

The Stinson is going to take a lot of power due to the higher power requirements of the digital servos and the lighting systems I plan to install. For power I decided on the Smart-Fly TurboReg. This regulator has 2 battery inputs for a redundant power source and it puts out 5.2v to 6.5v @ 17amps (with 8.4v input). I will be using two 2-cell lipos around 1000mah for the power input.

http://home.comcast.net/~ramovan/images/Stinson/SMT_TURBOREG.jpg
http://home.comcast.net/~ramovan/images/Stinson/20C_2cell_1000-300.jpg http://home.comcast.net/~ramovan/images/Stinson/20C_2cell_1000-300.jpg

tommyeflight89

Dec 07, 2008, 09:17 PM

Wow, this should be great.
I will gladly follow along.. The biggest electric I've done is the Topflite Spitfire kit. I am pretty sure the Stinson will build much the same. My only suggestion is build light. Unlike my Spitfire, its going to be hard to come out with a very high wing loading on this bird, but lower weight will fly longer!
You should be able to swap out much of the lite ply for an electric conversion. I looked through the manual and there isn't much sheeting which is good.
I would make your own firewall-forward pieces out of A/C ply because the TopFlite stuff is more doorskin plywood. It will be much stronger..

What are you going to cover with? I think fabirc covering with pinking tape would work really well for this.

ramovan

Dec 07, 2008, 09:53 PM

Good suggestion tommyeflight. The Stinson is a really stable flyer and I plan to put a really robust power system in it so I'm not too concerned about every drop of weight. I don't want to end up with a flying tank either so weight is certainly a concern.

The other electric conversions I've seen for this plane came in around 20lbs. I'll be adding a few fun extras to the plane so I think I may be a couple pounds more. The final weight will depend heavily on the covering a choose. I have not decided whether to use fabric or a monokote-like covering. The monokote would be much lighter, but the fabric would be more scale and would be totally painted making cowl/covering matching etc a non-issue. The problem is paint can add up to 3 pounds on a model this size! For this reason I'm still undecided and probably won't make a final decision for a few months when it's ready to cover. I definitely welcome any input on this.

In other Stinson electric conversions they have mentioned using lighter wood in some places of the build. So far I have the vertical and horizontal stabs, and a wing half built and have not seen any better wood selection that differs from the normal plans. It does mention some stronger (and heavier) ways of building like sheeting the entire horizontal stab, but I'm not doing this of course. There may be more weight saving oppertunities in the fuselage when I get there.

Fig Jam

Dec 07, 2008, 11:11 PM

ramovan

Dec 07, 2008, 11:32 PM

Randy,
Using Lipo's and a Reg is a little old school now ;) . Try 1 or 2 2s A123 packs without a Reg. Much cheaper and less to go wrong.
Mike

I agree, and that would likely be a weight savings; however, I already have the parts so I'll likely stick with the regulator. I like the ability to select the exact voltage output since I have several components to consider. I also likethe built-in redundancy of the TurboReg for some extra insurance. The two power inputs are isolated.

Fig Jam

Dec 07, 2008, 11:50 PM

I agree, and that would likely be a weight savings; however, I already have the parts so I'll likely stick with the regulator. I like the ability to select the exact voltage output since I have several components to consider. I also likethe built-in redundancy of the TurboReg for some extra insurance. The two power inputs are isolated.
I understand Randy, it's just that by switching over to A123's you will eliminate a point of failure (the Regulator) and if you use a AR9100 you would have redundancy. Just an idea.

Mike

ramovan

Dec 08, 2008, 12:40 AM

I understand Randy, it's just that by switching over to A123's you will eliminate a point of failure (the Regulator) and if you use a AR9100 you would have redundancy. Just an idea.
Mike

A 2-cell A123 would be 6.6v which is really too high for my use. Almost everything on board wants 5v to 6v input. 6.6v would be pushing it without a regulator. I'll probably run 5.5v just to be on the safe side.

I seriously thought about the Spektrum AR9000 but I'm not sure I want to spring for it. The AR7000 is a good full-range receiver, but it does seem almost ridiculous in a plane this big.

staggerwing

Dec 08, 2008, 06:10 AM

A weak structure in this kit is the split landing gear legs & the way they are mounted---tie/bolt them together w/ another pc of aluminum. You can see a pic of mine in my blog

feathermerchant

Dec 08, 2008, 07:44 AM

ramovan

Dec 08, 2008, 05:33 PM

A weak structure in this kit is the split landing gear legs & the way they are mounted---tie/bolt them together w/ another pc of aluminum. You can see a pic of mine in my blog

Very good point. Looking thru some of the other Stinson threads I can see the split landing gear is definitely a weak spot. I see others have used a one-piece aluminum landing gear from TNT. Looks like this is the way to go. The landing gear for the Stinson is $55.
http://www.tntlandinggear.com/store/shop/Product_List_Gear.htm

I'm still unsure about all the plastic parts that come with this "gold edition" kit. I really wish they would have provided fiberglass parts. I may go ahead and order the fiberglass cowl, pants, struts, etc from Fiberglass Specialties. Depends on how well the assembled plastic cowl turns out I guess.
http://www.fiberglassspecialtiesinc.com/

ramovan

Dec 08, 2008, 05:44 PM

Great project. Large electrics are really coming on.

LOTS of guys flying 50cc and up are using 1 or 2 2S a123's (2300mAh) with no regulator and no problems. I am using 2 2S A123 (1100's) on a 17lb Extra300. I have 5 HS 5955 servos (330 oz in) and I fly 5 flights between charges. I put about 400mAh in each pack when I charge. The AR9100 has 2 large guage power inputs and is rated up to 10V. Not as much bling as the regulator and fan but simpler and more reliable.

Oh I do not use the switch with the 9100. I just plug in the packs.

Larger electrics are gaining popularity as prices start to get more reasonable.

This will be my first giant scale electric and really a dream project I've wanted to do for a few years. My great aunt Loretta passed away earlier this year and left us all a little money to spend on something that we could remember her by. I used the money to buy the Stinson Reliant kit. My great aunt was a classy lady and I consider the Stinson the "Cadillac" of golden age airplanes. My great aunt was born in the same era as the Stinson so this build is dedicated to her, and my plane will be named "Loretta" somewhere on the outside.

Bladerunner1955

Dec 08, 2008, 11:10 PM

I flew mine with a AXI 5330/24 on 10 cells and could get 2 or 3 flights from one charge. Swings a 22/12, Flys like a dream. Here is a clip of it flying.
http://www.youtube.com/watch?v=8x0mFuR_Nz8
Don Hofeldt the electric guy

ramovan

Dec 09, 2008, 12:56 AM

Bladerunner,

That's awesome! Thanks for sharing the video. It's great inspiration. A lot of guys say this plane flies like a dream and I can see why in videos like that. Your Stinson turned out nice.

I can use your input since you've electrified this model. What is the capacity of your 10S lipo? Did you build/use the cowl that comes with the kit? I see you're using a wood prop. I plan to use one as well.

staggerwing

Dec 09, 2008, 06:05 AM

I'm still unsure about all the plastic parts that come with this "gold edition" kit. I really wish they would have provided fiberglass parts. I may go ahead and order the fiberglass cowl, pants, struts, etc from Fiberglass Specialties. Depends on how well the assembled plastic cowl turns out I guess.
http://www.fiberglassspecialtiesinc.com/

Yes, the plastic cowl is a problem trying to successfully join the two halves & the blisters---if you can do it, go w/ a F/G version. The gear leg fairings are a challenge also as once glued in place they will not take the gear flex . Try to fasten top end of fairings & not the lower so bottom portions can float or slip about the gear legs. The plastic cabin roof is another weak/poor structure ---for such a large beautifull plane, the plastic parts sure suck.

ramovan

Dec 09, 2008, 06:39 PM

Yes, the plastic cowl is a problem trying to successfully join the two halves & the blisters---if you can do it, go w/ a F/G version. The gear leg fairings are a challenge also as once glued in place they will not take the gear flex . Try to fasten top end of fairings & not the lower so bottom portions can float or slip about the gear legs. The plastic cabin roof is another weak/poor structure ---for such a large beautifull plane, the plastic parts sure suck.

No kidding. For something they call a "Gold Edition" kit some of these parts are pretty bad. I understand they are trying to keep the cost down, but an airplane this large and nice should really have fiberglass parts. The plastic parts are pretty cheesy. I suspect I'll be buying all the aftermarket fiberglass parts and aluminum one-piece landing gear. Thats about $200 for replacing parts that are in the $300 kit.

N99JH

Dec 09, 2008, 07:27 PM

With this much money in descent aftermarket replacement fiberglass parts you would have been better off scratchbuilding this model from Hostetler plans.

ramovan

Dec 09, 2008, 07:39 PM

With this much money in descent aftermarket replacement fiberglass parts you would have been better off scratchbuilding this model from Hostetler plans.

Possibly true, but the kit itself is pretty cheap, especially compared to the money it takes for all the other components. This kit is a lumberyard of parts that are mostly sticks and it takes so long for me to build it - I don't think I'd want to try it as a scratchbuild!

Really this kit should be $300 and then they should offer a REAL "Gold Edition" kit that has fiberglass parts instead of plastic for $400 or something. Anyhow, I love the size and the plane and it's a fun project so I'll try not to grumble too much.

cooper998

Dec 09, 2008, 08:07 PM

ramovan

Dec 09, 2008, 09:08 PM

R?C Dude,
I'll be following this build with interest, I have a kit in my stash that I obtained at a ridiculous price. I have read all the threads on the builds in the various forums and it looks like the plane can be finished out around 16 pounds. My Rascal 110 flew great with an AXI 5330/18 on 8s at the same weight so its definitely "doable".
I am curious to see how the new Scorpion motor will be set-up, looks like the magnet bell is unsupported at the back or will there be a bearing like the Hacker motors. Any more info available? the web site doesn't have them listed yet.

cooper998

I doubt I'll be any lighter than 20lbs on the Stinson. This is a luxury plane not a light model like a cub. Besides, I'll be adding a few bells and whistles. I'll weigh it when I'm done though and let everyone know.

I have not seen the new Scorpion 55mm motors yet - they are due in the next couple weeks. I'm sure they will have a bearing supporting the rear of the flux ring, and they install magnet retainers to make sure the magnets can't shift around too. Scorpion does this on all 3032 and larger motors. This would be especially important on the 55mm series! I don't think you can have that much power unsupported on one end.

ramovan

Dec 12, 2008, 12:40 AM

Since this is a kit I have a chance to install some lights before covering. I plan to run standard navigation lights - red and green on the wingtips, and white on the tail. I'd also like some landing lights in the leading edge of the wing and strobe lights on the wingtips. I may even put in some cabin lights. For control I'll be using the Dimension Engineering DELight lighting system. Most of the LEDs will be from DE as well. Their LEDs are mega-bright! I tried one the other day and I was seeing spots for a long time. They're also really small which will make installation easier. MPI makes some nice strobe lights.

http://home.comcast.net/~ramovan/images/Stinson/controllersmall-crop.jpg http://home.comcast.net/~ramovan/images/Stinson/acc248-smaller-crop.jpghttp://home.comcast.net/~ramovan/images/Stinson/NavLights.jpg

RiBell

Dec 12, 2008, 08:46 AM

I'd also like some landing lights in the leading edge of the wing
Before cutting into the leading edge of the wing for landing lights; check to make sure that that's where they are on the SR-9.
Many airplanes of this era had landing lights that retracted flush to the bottom of the wing; when turned off; and extended forward when turned on.
Rick

staggerwing

Dec 12, 2008, 02:58 PM

ramovan

Dec 15, 2008, 01:35 PM

My friend Bladerunner---
Don , I hope you don't mind this.
For all you readers who don't know of Don. he did a great amount of the elec design etc for the elec powered Spruce Goose model in the Howard Hughes movie, The Aviator, so when you see "Don Hofeldt the electric guy" , he is that.

Bladerunner has what I would call a "Dream Job"! Does he work with Larry Jolly at all? I used to work with Larry Jolly's brother here in Oregon.

ramovan

Dec 15, 2008, 01:54 PM

Before cutting into the leading edge of the wing for landing lights; check to make sure that that's where they are on the SR-9.
Many airplanes of this era had landing lights that retracted flush to the bottom of the wing; when turned off; and extended forward when turned on.
Rick

I've been trying to find some information on the Stinson's lights, but I haven't found any examples yet. Worse case I'll just install them in the standard locations. I'm not really going for perfect scale on this bird.

Yardbee

Dec 15, 2008, 10:00 PM

Ramovan: RiBell Is Correct! Check Out www.stinsonreliant.com A Website Dedicated for the Restoration Of Stinsons. The V-77 On the First Page Clearly Shows the Landing Light Underneath The Wing Flush Mounted & Not Retracted. Hope This Helps! :)

Best Regards: Joe

ramovan

Dec 15, 2008, 11:18 PM

Ramovan: RiBell Is Correct! Check Out www.stinsonreliant.com (http://www.stinsonreliant.com/) A Website Dedicated for the Restoration Of Stinsons. The V-77 On the First Page Clearly Shows the Landing Light Underneath The Wing Flush Mounted & Not Retracted. Hope This Helps! :)
Best Regards: Joe

Thanks Joe! Thats a great link. There's thousands of photos there that are going to be very helpful. I found lots of good pics showing the landing lights. You and Rick are right, they are mounted flush on the bottom of the wing. Much more in the middle than I expected. I found lots of good examples of the red/green wingtip lights too. They are more forward than I thought. Now I can install the lights a little more realistically although they still won't be "scale".

Now I just need to build another wing-half so I can install some lights.
http://home.comcast.net/~ramovan/images/stinsonlights1.jpg

Randy

Yardbee

Dec 16, 2008, 12:55 PM

Randy: Thats One Nice Looking Stinson!! Glad The Link Helped You!! :)

Cheers: Joe :)

guapoman2000

Dec 16, 2008, 08:23 PM

A 2-cell A123 would be 6.6v which is really too high for my use. Almost everything on board wants 5v to 6v input. 6.6v would be pushing it without a regulator. I'll probably run 5.5v just to be on the safe side.

I seriously thought about the Spektrum AR9000 but I'm not sure I want to spring for it. The AR7000 is a good full-range receiver, but it does seem almost ridiculous in a plane this big.

I fly a large Mid-West Citabria 80 3/4 inch wing span, of course no where near the size of your conversion with the Stinson but, I had some nasty Glitches with my Elevator (two servos) and it took me quite a while until I found out that I was pumping in more than 7 Volts un-regulated to my Electron-6 Dual Conversion receiver, using a 5-Cell 2500mAH, Ni-MH, Sanyo Pack.

I have to recommend a regulator between the Receiver and Receiver source. The regulators that I use go into a by-pass when it detects the battery to be at a lower Voltage than what it is trying to regulate to.

Good project Randy!

ramovan

Dec 18, 2008, 06:46 PM

I fly a large Mid-West Citabria 80 3/4 inch wing span, of course no where near the size of your conversion with the Stinson but, I had some nasty Glitches with my Elevator (two servos) and it took me quite a while until I found out that I was pumping in more than 7 Volts un-regulated to my Electron-6 Dual Conversion receiver, using a 5-Cell 2500mAH, Ni-MH, Sanyo Pack.
Good project Randy!

Thanks - That reaffirms I should use the regulator. Most electronics can handle an extra volt or two, but better be safe than sorry. Besides I already have the regulator so why not.

ramovan

Dec 18, 2008, 06:48 PM

Here is the elevator built up and ready for covering in a few months. There's a 12" ruler for size reference.

http://home.comcast.net/~ramovan/images/Stinson/Elevator-crop.jpg

ramovan

Dec 18, 2008, 06:50 PM

Here's the rudder - ready for covering. A tail light will need to be installed first.

http://home.comcast.net/~ramovan/images/Stinson/Rudder-crop.jpg

ramovan

Dec 18, 2008, 06:52 PM

Here is a wing half thats built-up. Lots of lights and connections to install before covering though.

Top
http://home.comcast.net/~ramovan/images/Stinson/WingTop-crop.jpg

Bottom
http://home.comcast.net/~ramovan/images/Stinson/WingBottom-crop.jpg

RiBell

Dec 18, 2008, 07:03 PM

Here is a wing half
Quick question:
is it designed as a 2 piece wing for storage and transport? I

Rick

ramovan

Dec 18, 2008, 08:04 PM

Quick question:
is it designed as a 2 piece wing for storage and transport? I

Rick

Yes, the wings detach from the fuse for transport. No way you would get this plane into most vehicles if the wings weren't removable.

I plan to use a 15-pin computer monitor connector installed at the wing root to make all the servo and light connections. I've seen others do that on this model and I think it's a great idea. I just want to plug the wing on the fuse and go without plugging in 5 plugs for each wing half.

Here an example with a 9-pin plug posted by X-craft
http://www.rcgroups.com/forums/showpost.php?p=6630396&postcount=11

Thomas B

Dec 19, 2008, 01:35 AM

RiBell

Dec 19, 2008, 07:06 PM

Yes, the wings detach from the fuse for transport. No way you would get this plane into most vehicles if the wings weren't removable.
Thanks I knew it came off :D
What I was kinda hoping it came off in TWO pieces.
Rick

ramovan

Dec 19, 2008, 11:44 PM

Thanks I knew it came off :D
What I was kinda hoping it came off in TWO pieces.
Rick

Well it is two wing halves if thats what you mean. Each wing is about 45" and connects onto the side of the fuse.

RiBell

Dec 21, 2008, 07:17 PM

Well it is two wing halves if thats what you mean. Each wing is about 45" and connects onto the side of the fuse.
Yes that's what I was asking about.
I guess my comment
I knew it came off
Was a weak attempt at humor.
Anyway thanks for the clarification on the 2 piece wing. I might just have to try and twist my friends arm and catch him in a weak moment as he has the kit; and he's just finished up a bigger one from plans with a Zenoah GT-80 in it. There are so many cool airplanes that I would like to build; it's tough to know where to start :) .
Rick

ramovan

Dec 30, 2008, 05:32 PM

Should be a great project. I think you might find that 12S will be overkill for a model like this. 12S will give it right at or near 3D power levels....:)

10S would likely be more than enough and even then flying it in a scale like fashion will require a good bit of throttling back.

I think you're probably right about this, but it will depend a lot on the motor I select too. There is going to be 10S and 12S Scorpion 55mm motors and I may chose the lower Kv of the two so I can run 12 cells. The advantage would be better efficiency with the higher voltage and less battery capacity needed (trading volts for capacity). I may be able to use a 12S 6000mah lipos instead of a 10S 8000mah. This should all become more clear once I see some motor specs and calculations.

You should know that I do tend to over-power my planes a bit. I like to have that extra power available in case I need to use it.

ed moore

Jan 10, 2009, 02:38 PM

:D .....yup.....dude does that indeed.....i know..... ;)

E-Challenged

Jan 13, 2009, 12:02 PM

There's a two year old thread on Scale Electric Planes forum on my 42" Berkeley Reliant conversion. I have always been nuts about Reliants but they have to have SR-7 flat pane windshield and cowl bumps. When I get my building facility set up again, I plan to design a larger lighter weight version with scale-like sprung landing gear and flaps. Here are some ideas you may want to think about.

1.Larger dummy radial engines and cowl rings need propellers twice the diameter of the cowl to counter prop blanking and drag. This means that you need to select a low KV outrunner motor (or maybe a geared in-runner) that can provide about 100 watts per pound and spin the large prop to provide adequate take off thrust and scale-like air speed with some reserve power so that you can cruise at 1/2 throttle. Try to select a motor, prop and battery set up that will have some excess of power as re-installing larger motors and battery packs can be a pain. Povide some inlets and outlets for cooling airflow, especially important on hot summer days.

2.Short nosed radial engine models tend to turn out very tail heavy requiring excessive ballast in the nose. On my little SR-7, I have the 1320ma 3S lipo pack protruding through the firewall next to the Essky 400XT outrunner. I have to remove prop and cowl ring to change battery packs. You will probably need to mount your packs vertically against the back of the firewall.
Use a prop blade to release velcro and remove packs. Keep all fuselage/tail feather/tail wheel weight aft of the wing as little as practical to minimize need for nose ballast. I used pull-pull linkage to rudder, elevator and scale location tail wheel to avoid weight of pushrods and hardware. Light weight iron-on covering can be considerably lighter than painted fabric.

3. Reliants are tough on landing gear legs and wheel pants especially on hard dirt and stubble fields. I used flexible plastic foam sheet from the craft store for landing gear leg covers. Wheel pants are removable and held on with velcro against a brass plate silver soldered to the gear leg. On your Reliant, I would try to design sprung landing gear legs that mimic full scale Reliants and covers that move inside the upper fuselage fairing like the real ones. You can get detailed Reliant drawings with landing gear details etc., from Bob Banka's documentation service.

4. Flying-The real Reliants were not floaters and flew fairly fast (Lear Jets of the 30's) They were surprisingly stable and resistant to tip stalls. With the proper amount of toe in and practice nudging right rudder, take off runs are quite dignified. My little Reliant often falls out of loops and rolls but the Reliant was not intended for aerobatics. I think that flaps would make landings slower and easier on landing gear.

Good luck with your Reliant, will be watching your progress.

PS: I fly at same Fairview park as Hofelt, never saw his Reliant fly though. My little Reliant just crashed with minor damage due to undetermined cause.

BoneDoc

Jan 13, 2009, 03:37 PM

What's the diameter of the cowling?

ramovan

Jan 13, 2009, 04:31 PM

What's the diameter of the cowling?

On the Top Flight kit I'm building the cowl is almost 10" in diameter (not including cowl bumps)

ramovan

Jan 13, 2009, 05:09 PM

E-Challenged,

Thanks for the insight - your personal experience with the Stinson is very helpful. Some of your observations will have influence on the power system I end up selecting. The comment on the low Kv motor makes me lean further towards the lower Kv 5535 motor so I can run a 12S lipo and a longer prop (20"?). I will be packing this thing with plently of power believe me.

I definitely want the "bumps" on the cowl and I really like the flat windshield on the SR-7. The plans call for a rounded windshield but the flat style should be doable.

Everyone talks about the landing gear on the Stinson so it's pretty obvious I need to stray from the plans a bit. I've seen some good ideas out there on adding some shock absorbing, but I'm leaning towards the after-market one-piece aluminum landing gear instead. Hopefully they have some shock absorbing in them and not too stiff.

I think you're right about the CG issue. I'm going to try to get my batteries as far forward as possible. Especially since the servos for rudder and elevator will be located in the back of the plane.

E-Challenged

Jan 13, 2009, 08:55 PM

I had to change the size and shape of the side windows to conform to SR-7/8
configuration as shown on Wylam drawings. The flat pane windshield framework and streamlined triangular top were quite easy to make.

E-Challenged

Jan 14, 2009, 09:54 AM

You don't have to follow the plans for servo , etc., mounting in that cavernous fuselage. Servos, receiver, etc., can be located on or in front of cg unless you intend to install seats and scale interior. With some compromises, you can probably do both. I'm a believer in lighter flies more scale-like and lasts longer. The less nose ballast you have to add, the better. That's a robust airframe designed for large gasoline engine stresses. Contact Lucien Miller, Innov8tive Designs, if you haven't done so already, for advice and help in choosing the right Scorpion motor, etc for this model. He also has a running thread in the Electric Power Systems forum on E-Zone where he answers questions and gives excellent advice.

ramovan

Jan 15, 2009, 04:55 PM

Actually the Top Flight Stinson kit is set up to locate the tail servos either up front towards the cabin, or in the back so it can easily be done either way. Yes, don't think space will be an issue in this honkin' fuse - LOL!

I speak to Lucien often and will definitely get his input when selecting the motor, but I'm pretty sure I'll be going with the 5535-160 which is a 40-45cc gas equivalent. That should move the plane around the sky quite nicely.

E-Challenged

Jan 18, 2009, 11:53 AM

A sound system would be cool. I have this idea for a ground based sound system controlled by small lightweight device in the plane. The device would tell the ground unit the volume and pitch/doppler effect to make as the plane's motor rpm rises and lowers and plane flies away or toward it. The ground unit could be made to simulate any type of piston engine or even jet sounds. Now if I had the electronic engineering skills......

Go here and click on Gallery to view three short videos, SR9 landing, taxiing and taking off, glorius large radial sound:

http://www.rangemedia.com.au/stinsonsr9e/index1.htm

diver don

Mar 26, 2009, 11:48 PM

How goes it?

We have missed you.

DD

ramovan

Mar 27, 2009, 01:16 AM

Funny you should write that today Don as I was about to revive this thread after all this time to say I've finally finished the second wing half. Yes, it actually took me that long to get it done! This kit takes a ton of hours to build but the main problem is finding time to work on it, so I've fallen way behind schedule. My new goal is a summer completion.

I got myself in the hobby room and spent some serious hours this past week to get the wing off the building board. Finally I can start on the fuse. Seems like it would be easier to build the second wing after gaining some experience building the first, but I have to say it was a little bit of torchure to build a wing AGAIN. Hate building something twice... especially when that something takes me a month.

I put the two wing halves together, joining them with the wing tube, so I could finally see the full wingspan. The gap between them looked way too wide for the fuse, but when I measured it was 100.5" tip to tip which is right on the specs. Guess the fuse really is that wide. You just can't appreciate how huge the wings are until you see them in person. I couldn't even imagine when building a wing half. I was just blown away by how big this model is going to be. Here's some pictures I took tonight. Sorry about the wood-on-wood background this time.

Servos are installed and linkages done, but I have to come back to the wings are some point to install lights and do a bunch of electrical work. Some sanding still needs to be done on that second wing half too.

http://home.comcast.net/~ramovan/images/StinsonWingWhole-1-crop2.JPG

http://home.comcast.net/~ramovan/images/StinsonWingWhole-3-crop2.JPG

http://home.comcast.net/~ramovan/images/StinsonWingWhole-5-crop2.JPG

http://home.comcast.net/~ramovan/images/StinsonWingWhole-4-crop2.jpg

Randy

diver don

Mar 27, 2009, 10:19 AM

Looken good.

One suggestion.
When you build the fuselage use the two plywood left and right deck pieces as a template to locate bulkheads 3,4 & 5. It will made your life much easier when you go to install them.
If you don't follow me I'll explain more.

Last night I installed the wing struts and here is also a pix of the baggage door with electric controls.(I shot the pix upside down so the kill switch looks like it's defying gravity).

DD

PS: The Futaba servo arm fits like a glove.

ramovan

Mar 28, 2009, 11:58 PM

Wow Don - You're way ahead of me! I just started the fuse tonight but that means building 9 fuse formers first. I think I understand what you're saying about using the deck pieces as a template. I'l be getting to that step in a few days when I actually start putting the fuse together. Looking thru the book it looks like I have a ton of work ahead on me.

I plan to do a baggage door with some electronics access similar to yours, but I think I am going to parallel 3 high current arming switches to carry all that power system current. I can't see how your wiring is set up, but if you have a single plug for the power system you might want to at least double it up. I don't think a single anderson power pole set can handle the power required. My power system is going to be 12S (44 volts) at somewhere around 60-90 amps. I imagine you'll be somewhere close to the same.

I also plan to put a few switches in that compartment for regulator, lights, etc. Looks like you made a way to not lose the arming plug... Thats a good idea!

ramovan

Apr 04, 2009, 06:48 PM

Unfortunately I was right and it took me a week to build the fuse formers F3 thru F8. Now we can start building a fuse.

http://home.comcast.net/~ramovan/images/FuseFormers3-8.jpg

RiBell

Apr 04, 2009, 07:40 PM

I put the two wing halves together, joining them with the wing tube, so I could finally see the full wingspan.
Is the wing tube a kit bash or is it the way it was designed.
Rick

ramovan

Apr 05, 2009, 01:33 PM

Rick,

That's the way the kit is designed - Not my kit bashing.

RiBell

Apr 05, 2009, 05:45 PM

Rick,

That's the way the kit is designed - Not my kit bashing.
Thanks:
A friend of mine has the kit and has just finished building a 1/4 scale SR-10 125" span from Wendell Hostetler Plans (http://www.hostetlersplans.com/) I might just have to try to twist his arm for the kit.
Rick

ramovan

Apr 05, 2009, 05:57 PM

Hey Don, can you share some detail on your landing lights under the wings? What lights/materials did you use? Got pictures? They look really scale and I'd like to do the same type of thing.

diver don

Apr 05, 2009, 10:51 PM

Hey Don, can you share some detail on your landing lights under the wings? What lights/materials did you use? Got pictures? They look really scale and I'd like to do the same type of thing.

Glad to.

The light it's self is the head and lens of a $2.00 flashlight from Wal-Mart.
The light source is the "DeLite" system fron Dimension Engineering ,that I'm sure your aware of.

The unite is set up on the gear switch with the light programmed on the DeLite controller to be "on" from 0% to 50% so it turns "on" as it comes down and "off" as it retracts.

What I realy like is the fact that I have a JR 9303 and can slow my servos down. This makes fror a very realistic deployment of things like lights and flaps.

Don

ramovan

Apr 21, 2009, 01:54 PM

Thanks Don - thats a great idea! I would like to do the same thing on my landing lights. Looks like I'll need a couple more servos in the plan. It's getting hard to fit eveything in the 10 available channels as that will make it 9 servos total.

I'm using Hyperion programmable digital servos so I plan to slow them down for landing lights and flaps as well.

ramovan

Apr 21, 2009, 01:57 PM

Finally starting to get the fuse built....

http://home.comcast.net/~ramovan/images/Fuse1.jpg

http://home.comcast.net/~ramovan/images/Fuse2.jpg

http://home.comcast.net/~ramovan/images/Fuse3.jpg

http://home.comcast.net/~ramovan/images/Fuse4.jpg

diver don

Apr 21, 2009, 08:44 PM

Coming right along.
Keep up the good work.

Don

E-Challenged

Apr 30, 2009, 12:06 PM

Have you seen the pictures of the old mail bag pickup by Reliant experiment? Might be good for a fun fly demonstration when you get the model trimmed out.

diver don

Apr 30, 2009, 10:21 PM

Have you seen the pictures of the old mail bag pickup by Reliant experiment? Might be good for a fun fly demonstration when you get the model trimmed out.

Could be interesting.

DD

ramovan

May 11, 2009, 08:22 PM

Found these great flashlights to use for landing lights at the hardware store. Aluminmum case with a 9-LED lense. $2.99 for a two pack red/blue. I bought two so I would have a pair of reds which should work well for my color scheme (put the blues in the lfightbox!). The lights are blinding-bright and run on 5v so perfect to tap into Rx power.

http://home.comcast.net/~ramovan/images/97036.gif

ramovan

May 11, 2009, 08:42 PM

Finished building the front to the point where I need a motor. Lots of other stuff still to work on though. I installed landing gear and went with the stock setup but beefed everything up quite a bit as I've heard it's pretty weak normally.

http://home.comcast.net/~ramovan/images/FuseFront-Gear-5.JPG

http://home.comcast.net/~ramovan/images/FuseFront-Gear-2.JPG

diver don

May 12, 2009, 12:39 AM

Lights look like a great find.

What motor have you decided on?

Don

ramovan

May 12, 2009, 02:30 PM

Lights look like a great find.
What motor have you decided on?
Don

I think I'm going with the Scorpion 5535-160 on a 12S 5500mah lipo. The motors are supposed to be available in about a week so the timing is about perfect for my build. Probably going to spin a 20" Xoar prop but I still need to work out the exact size after running some numbers on it. I'm going for about a 3000 watt setup.
http://www.scorpionsystem.com/catalog/motors/s55/S-5535-160KV/

There's a Scorpion 5545 series, but I think that may be over-kill. I want lots of power to spare, but I don't think I'll need 4500 watts! Scorpion is making the new generation of Hyperion motors by the way.

diver don

May 18, 2009, 07:47 PM

A very close final weight for mine.

Get ready for this.

24 1/2 lbs. WO BATTERIES

This is becoming very interesting.

Don

ramovan

May 18, 2009, 08:21 PM

A very close final weight for mine.
Get ready for this.
24 1/2 lbs. WO BATTERIES
This is becoming very interesting.
Don

WHAT?!?! That is way over my estimates! The review I read in QuietFlyer magazine has a flying weight just under 20lbs and that was with 10-cell 8000mah lipo. I thought I was being realistic counting on a 22lb flying weight with 12S 5500mah lipos. My lipos would weigh the same or less than the 8000mah packs. Each 6S 5500mah pack weighs 30.7oz so 2 packs is 62oz (3.84 lbs). If you put those in your plane you would be over 28lbs! :eek:

Are you sure there isn't a brick in there somewhere?

diver don

May 18, 2009, 08:48 PM

I'm going to rechech it tomorrow but I think I'm correct.

I was looking at useing A-123"s??????????

Don

ramovan

May 18, 2009, 08:51 PM

I'm going to rechech it tomorrow but I think I'm correct.

I was looking at useing A-123"s??????????

Don

A123's are a bit heavier but the 24 1/2 lbs weight without the batteries is still disturbing. Please let me know if you find that brick in the plane or if that weight is for real. You're scaring me man!

ramovan

May 18, 2009, 08:53 PM

BTW - The new Scorpion 55mm motors have been delivered and I am adding them to the website as we speak.

diver don

May 18, 2009, 09:13 PM

ramovan

May 18, 2009, 09:53 PM

I'm a dummy! Sorry for the scare.
Just went out and rechecked and we have a new winner.
Weight w/o batteries: 21lb. 2.4oz.
( That's also with the very heavy full landing gear)
Thats a little better, Pheeeeeew.
Don

So how ready-to-fly is that? Is you model totally complete except for the flight batteries? Covered? Which motor and ESC did you go with?

diver don

May 18, 2009, 10:01 PM

Everything but batts.

Motor is Hyperion 5045-18 w/ Castle 85HV.

I'll post some pix tomorrow.

Don

ramovan

May 19, 2009, 12:22 AM

Don,

Sounds like you'll end up around 25lbs flying weight. What covering did you decide to use? I'm trying to decide if I want to use fabric covering which would be heavier especially with the paint.

Your motor is very close to mine. The Hyperion has a smaller diameter but a longer body length. My motor, the 5535-160 is 2.3oz heavier which is basically the same weight on a plane this big. We should have similar performance. In the QF article the guy had a Himax 63mm motor on 10S for 2000 watts. He stated that it flew well and had power to spare. I'm aiming for a 3000 watt configuration. I think you'll be about the same. This is where having a baseline can make you feel better about your setup. After spending all that money you don't want to end up under-powered.

Looks like you'll need to get up to a 45v to 52v on that motor with A123 cells.

diver don

May 19, 2009, 11:59 AM

Right now I'm looking at 14S2P4600 A-123's with an APC 22x12 prop.

I used Monokote and here are a few prelim. pix.

Don

ramovan

May 19, 2009, 04:36 PM

Wow Don. Absolutely gorgeous! Fantastic paint job on the dummy engine and the cowl. I bought the dummy engine too. Hope mine turns out that nice.

If you're going to come in around 25lbs with Monokote perhaps I better think twice about the fabric covering. The main advantage I wanted with the fabric is being able to paint the entire model. That way I wouldn't have to worry about matching paint to covering.

diver don

May 19, 2009, 09:46 PM

Just remember that you used the sock landing gear which is a lot lighter than my full gear upgrade.

I wish I had made a weight comparison before I finished the gear out.

The difference between the two equals a lot of paint weight.

Don

diver don

May 27, 2009, 04:50 PM

ramovan

May 27, 2009, 05:09 PM

Just beautiful Don! Really nice job. Gives me some inspiration. I'm at the step where you mount the wings so I finally get to see the size of this thing all together.

So the battery location is going to have to be at the CG, huh? I'm also planning to put my lipos against the firewall so perhaps I should plan for it coming out nose heavy with the lipos there. I would really like to locate the tail servos in the cabin and not in the aft location. Perhaps I better re-think that. Where did you install your servos?

RiBell

May 27, 2009, 06:39 PM

Some final figures and a problem.

Final weight W/O batteries: 21 lb. 12 oz.

Using the forward wing bolt, which is within the suggested CG range, to suspend the model , she balances perfectly with the batteries removed.

I had made a hatch to place the batteries just behind the firewall so that is down the drain.
The batteries now will have to be located in the cabin right on the CG.

DD
Since it is a glow/gas conversion toss oh say 20oz of weight where the fuel tank would go; and compare that balance point with your balance point with your batt's installed. Remember that gas and glow airplanes are balanced without fuel. I would think that if your just a little bit forward; but not more forward than were it would end up if it was a fuel airplane with the tank full.
You might still be able to use your hatch just slide the batt's in as far as they will go.
Just a thought.
Rick

diver don

May 28, 2009, 01:44 PM

The servos were installed upside down under a hatch I made into the aft floor of the cabin.

The batts are 80 oz. and were set right where the fuel tank went so thanks, but don't think that will work.

Don

Peter M

May 29, 2009, 05:14 AM

Don,
Your Stinson looks great!

Can you tell me what brand spinner you are using please?

Good luck with your maiden! :)

Regards
Peter

dag214

May 29, 2009, 07:21 AM

Looking very VERY GOOD, I really love this plane.

DAG

diver don

May 29, 2009, 09:19 PM

Thanks, That's greatly appreciated gentleman.

Here's the link to the spinner.

I thought it was expensive but I just had to have it.http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKD69

Don

igal

May 31, 2009, 02:35 AM

Don,
I think this it the right spinner:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&P=8&I=LXKD66

Look at the bottom of the page
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNW28&P=0

Peter M

May 31, 2009, 05:36 AM

...I thought it was expensive but I just had to have it....

Don

Don,
That's what I thought when I saw it on your model and just had to ask where you got it! :D

Igal,
Thanks for those other links.

Regards
Peter

diver don

May 31, 2009, 01:41 PM

Don,
I think this it the right spinner:
http://www3.towerhobbies.com/cgi-bin/wti0001p?&P=8&I=LXKD66

Look at the bottom of the page
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNW28&P=0

Your right, but after looking at about 1000 pictures, I upped the size by 1/2"

In the end, I'm glad I did, because my final prop just fit and I think the smaller size would have been a problem.

Don

diver don

Jun 25, 2009, 10:28 PM

BTW - The new Scorpion 55mm motors have been delivered and I am adding them to the website as we speak.

How are you coming along.

Any tests on the 55"s.

Don

ramovan

Oct 29, 2009, 12:25 AM

Thought I might try to start this thread up again. It's Fall and finally time to start work on the Stinson giant scale on electric again. I was just too busy with other projects this summer to work on it so she's been sitting in the same state for about 5 months. About this time of year the rain starts up pretty good in Oregon so it feels like "winter build time" already. So we're making progress again. Really need to get this done before spring.

I left off at the begining of the good part. All the major components are built and I can begin installing all the electronics. First to be done was adding all the servos and control rods for elevators, rudder, and tailwheel. The pull-pull rudder and two elevator servos are all Hyperion DS20-UMD ultra-torque servos with 193oz of torque @ 6v.

http://home.comcast.net/~ramovan/images/Stinson/Stinson-ServoInstall-25.JPG

http://home.comcast.net/~ramovan/images/Stinson/Stinson-ServoInstall-24-800.JPG

feathermerchant

Oct 29, 2009, 06:06 AM

I use those on my 89" 3DHS Slick. Probly way overkill on this due to the relatively small throws. Looks great!

RiBell

Oct 29, 2009, 11:20 AM

About this time of year the rain starts up pretty good in Oregon so it feels like "winter build time" already. That it does. done before spring it's doable but not if you build as slow as me;) I don't even want to think of how many times I wanted to have an airplane finished by a certain time and things just didn't happen:o
God luck and were still watching. Quite interested in flight reports next spring/ summer
193oz tq wow:eek: guess that'll be enough:)
Rick

ramovan

Nov 01, 2009, 01:41 AM

For the tail wheel the direction tell you to gang steering control onto the rudder servo but I just didn;t like the thought of pull axtra load on one side of the pull-pull rudder after I just got the tension balanced. So I decided to install a separate standard-size low-profile metal-gear servo the HS-77BB. Shouldn't be a tail weight problem since you can install the tail servos back there as an option per the plans. The control rod was about 4 inches and it works great. Having this a separate sevo from the rudder will give me a lot more trimming and control flexibility so I'm pretty happy with it.

I made magnet snap-on hatches for access to this area later if needed. Those magnets are stronger than they look.

http://home.comcast.net/~ramovan/images/Stinson/Stinson-ServoInstall-07-800.JPG

http://home.comcast.net/~ramovan/images/Stinson/Stinson-ServoInstall-070-800.JPG

http://home.comcast.net/~ramovan/images/Stinson/Stinson-ServoInstall-071-800.JPG