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StayQuiet's blog
Posted by StayQuiet | Apr 05, 2014 @ 09:09 AM | 903 Views
More changes due. Fuselage is assembled, but I'm not completely happy with it. The picture of bulkhead B7 with the rear "window frame" assembled may be redesigned, along with bulkhead B2, which will make battery installation a lot easier. The tailboom has been scrapped, as it was just too heavy being made of lite ply, and the carbon fiber reinforcement just didn't stick. (Side note: does anyone know of a good cement that will stick to carbon fiber? Apparently, epoxy won't!) Redesigns have been made in CAD for the future, and the new tailboom will be made of 1/4" balsa with a 6mm X 1mm CF reinforcement insert to prevent flexing. Landing gear has been built (amazing, since I am the world's worst wire bender) and the tailwheel, which will be steerable, is a Du-Bro 60 size with a 1.25" wheel.
The remainder of the laser cut parts arrived, and tail construction will begin as soon as I get my workbench cleaned off!
Posted by StayQuiet | Mar 27, 2014 @ 06:53 PM | 1,407 Views
Waiting for the remainder of my laser cut parts to arrive. Fuselage and boom assembly revealed one very small issue that will be corrected in Version 2. I'm using 4mm carbon fiber square tubing to reinforce the boom, sandwiched between two sections of 1/8" lite ply. I thought that would give me the space needed to run a Sullivan tube through the middle for elevator control. Well, almost. Version 2 will use 5mm carbon fiber square tubing. (I did get the control rod tube routed, but I had to groove one section of lite ply to do it.) So, a minor design modification of bulkheads 6 and 7, where the boom fits, will be in order.

Bulkhead 7 has sections glued to the rear to form the large rear observation window. I may tweak that a bit as well, as forming the rear and side glass looks like it may be a challenge. But, scratch building is all about the challenge, isn't it?

I'll add pictures when I make a bit more progress.
Posted by StayQuiet | Mar 21, 2014 @ 03:33 PM | 993 Views
My first package from National Balsa arrived today. Well packed, absolutely no damage. Two large sheets of 1/8" lite ply with several pieces laser cut. Excellent job!

All I have to do is cut out the small tabs that hold things to the sheet (they were intentionally designed in) and label all the parts. B2 (bulkhead #2, the motor mount) has to be recut in 1/8" birch ply before full fuselage assembly can be completed, but that was my fault, not theirs.

A trip to the LHS, where I grabbed a section of 4mm square carbon fiber tubing for boom reinforcement, and a #503 Sullivan Golden Rod set for elevator control. The outer sheath must be installed in the boom before it all gets glued together.
Posted by StayQuiet | Mar 18, 2014 @ 11:58 AM | 906 Views
Still drawing up parts in CAD to be laser cut. Horizontal stab, verticle stabs, and elevator are done up, as well as the built up ailerons/flaperons. I also realized (too late) that my motor mount bulkhead (B2) was accidently placed on the lite ply sheet layout, instead of the birch plywood sheet layout, so I'll have to have that cut on the second round of parts. No matter, I also discovered that I mis-read the dimension spec of the mounting bolts on the motor X mount. The CAD plan has them spaced at 40mm, when they are actually 42mm. So, a quick redraw to the correct size, and a layout on the correct material are done.

My co-worker is just starting into the hobby, and has already told me that if the prototype flys well, he is going to have a short kit cut for himself as his first 'from scratch' build.
Posted by StayQuiet | Mar 11, 2014 @ 05:29 PM | 1,936 Views
Changes made to the rear boom. I was concerned about it flexing too much, so the new design is reinforced with two lengths of 4mm carbon fiber square tubing sandwiched between two lite ply sections. Makes a nice way to run the elevator control rod as well.

This necessitated a slight redesign of B6 and B7 fuse bulkheads. I must be getting better at CAD, because it almost seemed easy to accomplish.

Oh, by the way, the plans I'm basing this design on are featured here on the forums. They are really from 1950, and the design was for a free flight model. They are only useful for some general dimensions - the rest is up to me.

All the lite ply parts have been laid out for laser cutting, and the files sent out for a quote. Once they come back, fuselage assembly should go fairly quickly. I designed all the major pieces to fit together with slots and tabs.

While I wait for these parts, I'll start work on the tail feathers and wing design. My original intent was to have operational rudders, but that would be just too much linkage and hassle, so it will be a 'yank and bank' model. However, I'm still using ch.4 to control a steerable tailwheel for ground handling.
Posted by StayQuiet | Mar 08, 2014 @ 06:53 AM | 861 Views
I have to remind myself to set an alarm when I sit in front of my CAD screen. My wife does not appreciate me coming to bed at 2AM, muttering about how B2 has to be changed.

Anyway, the paper mockup is done. I discovered that the top of B2 was too tall. B1, B2, B3, and B4 all have to line up on top in a sloping plane for later sheeting. A slight change in dimension worked.

I also modified the design of B6 and B7 after I came up with a brilliant idea for the boom construction (this was about 3AM - wife was not happy when I turned on the nightlight to jot down some notes) and tail section.

Yes, the mockup looks ugly. But in reality, the real plane was no beauty! I did some research and found out the real thing used flaperons. Anybody know how to set up a Futaba 6EX for flaperons?
Posted by StayQuiet | Mar 07, 2014 @ 07:52 PM | 1,168 Views
It seems I've recaptured the building bug. One project done (twin powered electric MidStar 40) and looking for something different.

What I found was the Boeing L15 Scout. I've found two sets of plans, each with a different take on the plane. One is a park flyer (really more like a backyard flyer) and one is what appears to be a very old set of poorly drawn plans for about a .20 size engine (access to compression lever?)

I'm borrowing a little bit of both to come up with something that will be a "sort-of" stand off scale model with around a 50" wingspan. Electric power, of course!

I've done some preliminary drawings - more like scribbled notes for ideas on how to build the fuselage, tail boom, wings, etc - and have started in with my DesignCad program. The beauty about CAD is that you can print out your parts on paper, cut them out, and tape them together to see how they all fit. It's a great way to find the "oops" in your design before it gets expensive.

I'll do my best to document this build step by step, with lots of pictures and build notes. Please feel free to follow along, and submit comments and suggestions. If the finished product flies well, I'll happily upload all the CAD files. You can send them out and have a short kit cut up for yourself. All I ask is that you don't sell the files in any format.

This may be a slow build (I'm still learning CAD, but getting better at it!) so bear with me, okay?
Posted by StayQuiet | Mar 01, 2014 @ 05:32 PM | 898 Views
This has been a fun winter project (now if winter would only cooperate and end... )

With everything installed, I placed the plane on the balancer to see where I would have to add weight, or if I had to move the batteries around. To my surprise, the balance was absolutely perfect as set up! I actually took it off and reset it again, just to make certain.

Can't wait for all this snow to melt, and to get some flying weather.
Posted by StayQuiet | Feb 25, 2014 @ 06:02 PM | 1,203 Views
Tail is on (okay, I still have to hinge and cover) and the wing needs covering, but at least I got the fuselage done. I've run the motors up - they PULL! I don't think there will be any problem getting this bird in the air (at least a lack of power won't be a good excuse).
Posted by StayQuiet | Feb 15, 2014 @ 07:13 PM | 1,076 Views
Fuselage is done, with the exception of the tail feathers.

I've installed the servos for the rudder and elevator in the fuselage, and two aileron servos in the wing. ESC's are mounted above the lower air scoop. The lipo motor batteries (2 in parallel) mount on an extended fuel tank tray and are secured with a strap. I did build the nosepiece, and it slides in nicely and locks in place with magnets.

My wife grabbed a cellphone pic before I pinned in the tail sections. I wanted to see just how the balance was going to be, as I had some leeway in battery placement. To my delight, things were very close to being balanced, so there may only be a small amount of weight in the tail to get things perfect - but I'll wait until everything is installed and covered before I worry about that.
Posted by StayQuiet | Feb 04, 2014 @ 08:55 AM | 1,357 Views
Both wing halves are built. The second half went much more quickly, as the redesign details had already been worked out.

Wing panels have been joined, and motor nacelles epoxied in place. Aileron servos have been mounted on mounts fabricated from aluminum angle (1/16" by 3/4" by 3/4") epoxied to plywood, and held in place in the wing with six button head screws.

The building board has been cleared, and fuselage plans laid out on it. Still trying to decide how to enclose the nose where the motor would normally mount, since there won't be one there anymore. I'd like to make a nicely curved nosepiece that would be held in place with rare earth magnets, and used as a hatch to slide in the battery packs. On the other hand, the original plans have an access hatch on the top forward fuse, so that may be unneeded. Still, I want to mount the batteries as far forward as possible for balance, since there won't be any motor weight up front.

I'm also planning to add a cooling air scoop (sort of like that on a P-51 Mustang) to bring air into the fuse to cool the ESCs. Outlet will be up on the turtledeck. More thinking tonight.
Posted by StayQuiet | Jan 25, 2014 @ 08:23 PM | 1,360 Views
Decisions have been made. Aileron servos are being mounted in the wings - one for each aileron. Right wing is coming along nicely (yes, I'm in no rush on this project!) I still have some trimming, the wingtip to attach, and a few other 'incidentals' but I'm happy with the redesign results.

Motor nacelles have 2 degree downthrust built in (to match original plan). I ended up with APC 12X6E two blade props - one pusher for counter rotating units, anyway. Plus, I could get some Tru-Turn spinners to fit. Nacelle is shown in place, but hasn't been attached. I'll have 1/2" of clearance between the prop tip and fuselage side - if I measured correctly, that is.
Posted by StayQuiet | Jan 04, 2014 @ 06:39 PM | 1,085 Views
Looking over the wing plan, which is now laid out on my building board. I've marked out where the motor nacelles will be. I'll be extending the wing sheeting outward an additional 2 ribs, which means that four W2 ribs will have to be trimmed down to W1 ribs to allow for the thickness of the balsa sheeting.

I'm also going to add two half ribs (I call them W1-A) from the LE to the shear webbing right under the area where the nacelles will attach.

Since I've already sent out an order to the laser cutter (and I'm terrible at designing ribs with spar cutouts) I just made photocopies of the W1 ribs, cut and glued to 1/16" ply, cut the ply into templates, clamped in four W2 ribs, and sanded them down to the proper size. Cut the templates down and repeated the process on some fresh balsa to make up four W1-A half ribs.

Still debating on if I should follow the plans for a single aileron servo, or design mounts and hatches for individual servos.

I have to decide soon. I have to remember to drill some holes in some of the ribs for aileron servo leads, and motor lead wires.
Posted by StayQuiet | Dec 30, 2013 @ 08:43 PM | 1,299 Views
Ugh. Plans for the motor nacelles and bulkheads have been sent to the laser cutter. Just playing around with fitting the props and spinners to the motor adapters.

Guess what? Standard 2" diameter Du-Bro 3 blade spinners don't really fit pusher props, nor do they clear the hub.

Sent a message out to Tru-Turn to inquire about having a pair of 2" or 2.25" aluminum spinners made to fit the props (one standard, one pusher). I have a feeling this project just got a bit more expensive.
Posted by StayQuiet | Dec 28, 2013 @ 04:04 PM | 1,508 Views
The sides (inner and outer) of the engine nacelles have been drawn up in CAD. All I have to do is lay out the number that are needed, and send the files out to the laser cutter. Of course, I may still have to draw up a couple of extra wing ribs, just to reinforce the nacelle mounting points on the wing.

Post office dropped of a couple of boxes for me today as well. One from Tower Hobbies, and one from Heads Up RC. That means I have about 90% of what I need to start building, once the laser cut stuff is done.
Posted by StayQuiet | Dec 26, 2013 @ 10:55 AM | 1,399 Views
My wife gave me the okay to order up all the stuff I need for this project - motors, batteries, servos, ESCs, etc. Then she surprised me and told me it would be my Xmas gift! Gotta love her!

Started work in CAD with something simple, as my CAD skill has gotten a bit rusty. Motor bulkhead design was relatively easy, after a few miscues with the arc command. By designing in CAD, at least I know the motors will be centered perfectly in place, because the screw holes for the X motor mounts will be precisely made. Rather than doing this design in inches, as I have in the past, I'm converting my measurement to millimeters. It makes working in CAD so much easier, at least for me.
Posted by StayQuiet | Dec 23, 2013 @ 10:24 AM | 1,404 Views
Well, the idea of building a 75% sized MidStar 40 and powering it with twin electrics seemed to take a back seat for awhile. After drawing up a wing layout in CAD, I got sidetracked with building a Mik's FunBat just to fly around in a field across the street from my house (with the owner's permission, of course!)

I've decided that small planes, regardless of landing gear layout, just aren't going to work well at the local fields without rediculously large wheels. It's back to the .40 sized planes, and I just picked up (ta-dah!) a Mid Star 40 kit at Creative Hobbies in Mendon (thanks, Joe!)

Not being content to leave well enough alone, I'm going to convert it to twin electric power. I saw an article about someone who had done the same with a Four Star 40, but I'm doing it a bit differently. Different design of the motor nacelles (CAD, of course). I'm going to use counter rotating 3 blade props - just because I like the look (I've always loved the P-38 Lightning.)

Time to launch MotoCalc for power requirements. Is it just me, or does anyone else feel the motor list is in terrible need of update? Anyway, I looked at what was used on the Four Star twin project, what MotoCalc recommended, and did a little comparison research to come up with something that was (a) available, (b) comparable, and (c) reasonably priced. A pair of .25 equivalent motors with 80 amp ESCs and parallel 2200mah 50C lipos from Heads Up RC will be powering this project.

I'm going to start designing the nacelles tomorrow, and put together a parts list. Maybe do a little online shopping while I'm at work It's the holiday week, things are pretty slow in the office. Sounds like a good excuse to me.
Posted by StayQuiet | May 01, 2012 @ 06:53 PM | 1,368 Views
After a few nights with the CAD program, and a few "hmmm, that doesn't look right" moments with subsequent changes, I came to a conclusion: I'm still going to end up with small wheels for landing gear, or a plane with rediculously large wheels. After tearing up the gear on one of my other planes on landing (honest, the landing wasn't bad on my part) this may not be worth the trouble.
Posted by StayQuiet | Apr 26, 2012 @ 12:40 PM | 1,671 Views
Here's the plan: take the basic design of the Sig MidStar 40, shrink it to 75% of the original size, close the nose, add in two engine nacelles on the wings, power it with a pair of brushless motors, draw it all up in CAD, get a short kit laser cut, and build the plane.

Should be done by the weekend.

Plan set from Sig arrived in yesterday's mail. I only wish the other plans services were that fast! Today I had them copied at 75% of original size, two sets. I've guesstimated the weight of the smaller airframe, figured the new wing area and span, and plugged it all into MotoCalc to come up with some motor/ESC/battery combinations that would work. A quick email to HeadsUpRC yielded less expensive alternatives to the OS motors suggested by MotoCalc (basically, I can get the needed two motors for less than the cost of one OS). I'm going with Master Airscrew 8X6 three blades, counter rotating - mainly because I think three bladed props look cool, but also because they will give me some extra ground clearance for the field, where the grass can be a bit long at times.

Tonight I'm going to start working with the CAD program to get the engine nacelles figured out - right after I get my better half calmed down when she sees me unrolling yet another set of plans.
Posted by StayQuiet | Apr 23, 2012 @ 10:18 AM | 1,604 Views
I had a lot of fun with my Demi Duster project, but that twin engine dream keeps nagging me.

Our club field isn't exactly perfect yet (it's a work in progress) so there are some issues flying small taildragger electrics from it. Wheels tend to get caught in grass (or dirt) clumps, and the plane noses over on rollout.

I'm thinking tricycle gear. Years ago I flew a Sig MidStar 40 (glow) and enjoyed the plane. Rather than build a kit and convert it to electric, I'm thinking of getting a set of plans from Sig, having them copied at 75% of original size, for a wingspan of a bit under 48.5", closing off the nose, and adding in two motor nacelles on the wing. Draw it all up in CAD and have a short kit laser cut. Think of the offspring from a Hobbico Twinstar and the Sig Midstar 40 at 75% original size - a Twinstar 30?

My wife is going to kill me when she sees me building another one.