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Posted by jmxp69 | Oct 26, 2017 @ 05:53 PM | 1,071 Views
As I my interest in fast-mover type planes has grown lately, I've wanted to measure airplane speed. I know a radar gun is an obvious answer, but there are issues with positioning, finding a willing helper, flying the plane at the gun (and helper) etc. Pitot tube sensors are an option as well and for a very accurate measure, I may try something like that soon.

Thanks to RCG and a little bit of research, I found a reasonable and cheap [free] alternative using a sound recording and doppler analysis software. I put a video together demonstrating the process start to finish.

Have fun...

How Fast Does it Fly? How-to Measure RC Plane Speed without a Radar Gun [tech] (11 min 49 sec)

Posted by jmxp69 | Oct 08, 2017 @ 07:30 PM | 1,262 Views
If you follow my blog here on RCG or my Youtube channel, you'll know I've become interested in building a fast--100++mph--plane. I started out with the FT Racer. After fooling around with motor/prop combos I realized the plane could be spirited but it wouldn't make the grade. So I started searching for plans and came across Nic Lechner's Mig3 and P-39. Both of those airframes utilized techniques designed for a fast mover. Key among them: Reinforced double layer true airfoil stabilizer and double layer vertical stabilizer. Aluminum reinforced wing with a knife edge trailing edge, and wing/fuselage filets. Nic also produced a video clocking his P39 with a radar gun at 121mph. So I found the platform.

Nic borrows heavily from Flite Test but adds some advanced techniques to his plans such as sculpting the foam to provide knife edge trailing edges. He also uses BBQ skewers to reinforce the nose along the main deck. This little extra supports the use of higher output motors required to hit the speed target. He has a very nice build video for the P-39.

Anyway, here is my build review video of the P-39 and my experience with the 2nd flight. My maiden takeoff was actually much more controlled than the takeoff in the video below as I had someone hand launch for me while I focused on the controls. On the 2nd launch, I gave it an underhand toss with too much AoA and Yaw. Thankfully I managed to get it under control and finish the flight.

I'm using an Emax 2812/06 which is a 3535mm 1550kv motor on 4s with an 8x8 prop. I'm going to try a 9x9 and see what I think of it. I have no honest way of knowing if this plane made 100mph or not; however, whether I actually achieved 100mph is academic for me at this point. The plane is fast, faster than any other model I've flown, so my "need for speed" is satisfied (for the time being).

Thanks to Nic for sharing his plans.

nnP-39 Build Review Goal: 100+MPH (15 min 54 sec)

100MPH Foam Board Airplane nnP-39 Maiden *Holy $!@&* (5 min 15 sec)

Posted by jmxp69 | Sep 03, 2017 @ 12:15 AM | 1,379 Views
Lately I've had this urge to fly something really fast and to reduce the stress level a little. I've recently built and maidened a couple of 55" class balsa builds and while I've had some success I wanted something to bring the tension level down some.

It's been about 18 months since I built or flew a Flite Test plane so I scanned their plans and I found the Racer. I went through my spare parts and found a Turnigy 2826 2200kv, 7x6 APC clone, a 30a ESC, a 4 channel Rx and some lightweight landing gear. So I ran to Dollar Tree, bought a stack of foam, hot glue, and posterboard. The following video and pics are the result of my build.

eCalc estimated power @ ~280w. My watt meter showed well over 400w. Not sure why the difference. So I propped down a touch by going to a 3 blade 7x4. I probably need a something like a 6x4 or a 40a ESC. I'll just keep my thumb off the gas for now. For the main gear, I removed the tape and paper under the mounting block. I affixed the block to the fuse with epoxy, and the gear to the block with a couple of wood screws. For the tail, I used a blank gift card and made a skid. I expect takeoff to be a point and shoot affair. Originally I planned on using the standard Racer canopy. Then the wife thought the Ripslinger arrangement would look better instead (sigh).

Maiden video will be posted to this entry tomorrow.

Flite Test Racer Build Review [FT Slinger] (13 min 15 sec)

Maiden and post flight discussion.
Flite Test Racer Maiden and Post Flight [FT Slinger] - Round 1 (5 min 55 sec)

Posted by jmxp69 | Aug 11, 2017 @ 09:22 PM | 1,395 Views
I've been thoroughly enjoying my Phoenix Model airplanes. They make solid kits. There are some concessions in details, but for the price, I think the concessions are worth it. One example on the Spitfire are the gear doors that sit a full 1/2" above the lower wing surface when the gear are retracted. It's ugly, not aerodynamic, and could be fixed.

Anyway, the plane flew great even if the pilot needs some work...Enjoy the video.

Spitfire Maiden and 2nd Flight [Phoenix Model] [Parkfly] (9 min 44 sec)

Posted by jmxp69 | Jul 29, 2017 @ 11:06 AM | 2,132 Views
My all time favorite plane for daily flying is the Tower Hobbies Millennium Master. That plane goes with me every time I fly. I've been looking for a step-up successor for the MM now that I have access to a paved runway and a much larger flying field. The Pilatus PC-9 checked a lot of boxes for me:

1) Phoenix Model - They make solid ARF kits. Covering has always been very good and requisite hard points (landing gear, motor mount, wing joints) always seem to be built strong.

2) Low Wing - The MM has a low swept wing. The PC-9 has a low moderate sweep with dihedral. So it may not be as docile inverted as the MM but I don't fly inverted that much anyway; and, I'll get the added stability benefit of moderate dihedral with the PC-9.

3) Tricycle Retracts - Trikes lend themselves well to paved surfaces. The MM has fixed tricycle gear, the PC-9 has retract trike gear. Big plus on this point.

4) Balsa Construction - In my new location, wind is more of a factor than it used to be. Balsa planes just fly smoother in windy conditions. They're also more resistant to hangar rash.

5) Bigger Motor/More Speed - The PC-9 is a .46-.55 class plane, so I can use a bigger motor, higher cell count, and fly faster - However, the MM is no slouch with a 3s 9x7 on the stock motor.

I know there are other sport planes that check some of these boxes but the PC-9 checked most of the boxes for me as a successor. As of this writing, I've just started the assembly. I'll post the build...Continue Reading
Posted by jmxp69 | Jul 22, 2017 @ 09:53 PM | 2,452 Views
Aloft recently had a sale featuring the Tidewater. I did a little reading and the best I can figure, this is a Flyzone design currently carried by Tower in a receiver ready configuration for about $170. Aloft's version comes in kit form i.e. no electronics for $55. The Aloft version of the plane is made by T&B Model (Hong Kong) and it is clearly a Flyzone knock-off. Even the manual used the same fonts and print layout. The plane has graphics on the Fuse that say "Seagull". The box says Tidewater and Seagull. For me, it's just a Tidewater.

The following videos go through the unbox, build and maiden. Nothing particularly illuminating, but I have a few thoughts on the plane.

1) The battery hatch on the nose would be a great place for FPV Cam/Tx. Eventually I'll put some gear on it and fly it that way.
2) The battery compartment is big enough and placed close enough to CG to allow some experimentation with battery size. I'm confident a Multi-star 5000 3s pack will fit and balance.
3) Rudder is required - I've flown the plane a couple of times now and rudder is necessary. It gets uncoordinated in yank and bank only maneuvers. That's not to say uncontrollable, but it does get sloppy. If you're not a regular rudder user (you know who you are), this plane would probably be a good candidate for some aileron/rudder mixing.
4) It does loop and roll but I wouldn't call that a strong suit, nor should it be. It's a short span, high mount wing with dihedral. It's just a docile little flyer.

In closing, it would be difficult to fault this $55 plane. It flies fine, no drama taking off or landing. Fit and finish are acceptable. Not much more to say...

Tidewater Seagull Unbox (9 min 45 sec)

Build Review:
Tech - Tidewater Seaplane Build Review (7 min 1 sec)

ParkFly - T&B Model Tidewater (Seagull) Maiden (9 min 20 sec)

Posted by jmxp69 | Aug 01, 2016 @ 05:06 PM | 2,650 Views
I respect the fact that if you're already an RCG user you probably don't need this video; however, how many times have you been approached at the field asking for this type of info?

Obviously you'll have your own approach and preferred products--that's fine. Just take a look at the video below and if you agree with the premise--use it as reference material for rookies you encounter. If you think I'm totally off base, keep doing what you've been doing--but the video stays

The primary motivation for this was a new guy I encountered the other day who was still spending $50 for small batteries and thought his only option for a replacement motor on an Apprentice was going to cost him $70--after ONE flight! I just couldn't abide that and felt obligated to show budget alternatives.

How to Get Started in Radio Control Flying (24 min 5 sec)

Posted by jmxp69 | Jul 30, 2016 @ 04:13 PM | 3,191 Views
Got to fly the Spitfire today after my modifications and I'm very happy with the outcome.

With 4s power, a 50a ESC and ventilation cutouts I made, the plane now flies the way it should. The power level just feels right.

Still a little tweaking to do with CG. I moved from 72mm where I had it on the maiden to 78mm and the plane flew great. I'm going to move it back 5mm further to see if I can snuff out the landing roll-out tip over.

In-fact, that's the only thing left to sort out on this plane. Once I stop the landing roll-out tipping issue the Spitfire will be perfect in my opinion.

Check out the video to see how the plane performs with the adjustments I made:
TestFlight - Dynam Spitfire Flight Evaluation after Mods (6 min 59 sec)

Posted by jmxp69 | Jul 29, 2016 @ 07:30 PM | 3,447 Views
After the Spitfire maiden I made a mental hit list of issues to work out.

- Ventilation
- Power management
- Adjust CG aft

This video walks through what I did to address the issues I uncovered in the maiden. I hope the measures I took around CG and ground handling are enough to mitigate nose overs. We'll see...

Tech Dynam Spitfire Performance Modifications and Upgrades (16 min 3 sec)

Posted by jmxp69 | Jul 28, 2016 @ 12:25 AM | 3,288 Views
I took the Spitfire out for its maiden flight today. As much as I like Dynam planes (I really do) the Spitfire suffers from some of the same issues as e-v-e-r-y o-t-h-e-r Dynam plane I've flown.

Namely: Power is marginal and it is prone to tipping on grass due to landing gear rake.

I flew the maiden with a 4s 2200 25c Zippy compact and it made 'good enough' power but I landed early due to loss of power I attribute to the ESC getting hot. Just like the Mustang, the Spitfire isn't molded with any ventilation. So I'll be cutting a hole under the spinner and in the bottom of the fuse near the tail to get some air moving through the plane.

Ok, gripes aside, the plane flies much like the Dynam P-47D Thunderbolt. It's very docile with a highly visible profile; although, the blue does blend with the sky. The Spitfire shares a similar wing shape and I suspect similar wing loading with the Thunderbolt which explains why it's such a cupcake to fly.

Planned mods:
- Rake the gear even more forward than I already have.
- Move CG back from 72mm to 77mm.
- Bend the tailwheel to lower the tail to try and cure the tip-overs.

- Stellar looking plane. Has the best paint and best fitment of any Dynam plane I have so far.
- Great in-flight profile aids visibility.
- Light wingloading makes it extremely easy to fly. After curing the tipping issues this would be a very good first warbird.

- No ventilation for the ESC.
- Gear rake is not enough for grass fields.
- Power on 3s is marginal. It flies, but lacks inspiration.
- Did I mention ventilation? Seriously Dynam, you have to flow air over electronics.

Hope you enjoy the video:
ParkFly - Dynam Spitfire Maiden Flight and Review (16 min 36 sec)

Posted by jmxp69 | Jul 25, 2016 @ 09:36 PM | 3,338 Views
While in California recently I had a chance to stop by General Hobby and pick up a couple of airplanes. I went to work right away on the Spitfire and here's what I learned during the build.

Tech - Dynam Supermarine Spitfire 1200mm (47") Build Review (16 min 2 sec)

I really have no idea from a production design timeline point of view when the Spitfire entered the Dynam lineup, but I get the feeling it is one of their later planes because they've cured some of the issues I saw in previous builds. First up, the wing attachment strategy is very good on the Spitfire. You connect both wing halves via carbon spar and set the entire assembly into the saddle beneath the fuselage. Four screws to secure and the wings are on.

In the retracted position, the retractable landing gear fit the wheel wells perfectly. They are night and day compared to the Hellcat whose wheel covers sagged below the fuse while retracted.

It seems Dynam also addressed the prop shaft on the Spitfire. The Mustang motor shaft is very short and the collet barely fits on the end by the time you fit the spinner backplate resulting in very little motor shaft surface area for the compression collet to grip. On the Spitfire, everything fits together much better. There is plenty of room for the compression fitting to grip the motor shaft and therefore, it was much easier to tighten the prop nut and get a secure grip on the shaft.

Paint seems better too. The Corsair had some uncovered areas...Continue Reading
Posted by jmxp69 | Jul 16, 2016 @ 11:34 PM | 3,482 Views
I maidened my GWS C47 today and got bit by the early takeoff tip stall due to the high wing incidence. Damage was minimal but the nose took a pretty good hit.

The video below shows how I repaired it with Foam-tac Foam Finish with no sanding other than the initial prep to remove paint and take the ridges down.

Tech - How to Repair EPS or EPO with Foam-Tac Foam Finish (12 min 36 sec)

Posted by jmxp69 | Jul 12, 2016 @ 06:14 PM | 3,773 Views
GWS had a crazy 4th of July Sale. They had their 47" C-47 (DC3) on sale: 4 planes for $20. With shipping, the price came out to $13 per plane. For that price, I had to give it a whirl. This isn't going to be a step-by-step guide. I'm just going to put some information together in a single place that I had to go hunt down. It will also provide some build tips I used to ease assembly.

Quick facts for anybody looking at this plane:

Foam: EPS (styrofoam)
Prop size: MAS 6x4x3 fits. MAS 7x4x3 does not fit.
Motors: Emax 2822 1200kv
ESC: 30a Hobbywing
Graphics: Callie....who else? Miss Virginia livery.
Glue: Foamtac. Thin layers!
Paint: Cheap acrylic from Michaels brushed on.
Battery: 3s 2200 if I can get it to fit.
Servos: 3x9g Towerpros

Originally I thought I'd put retracts, flaps, and lights on this plane. Once I got a look inside and realized how cramped it would be just getting the standard configuration put together, I abandoned that idea. Since this plane was designed to fly with brushed motors, it's very light.

The fuselage required some foam tac filler to even up the seams. Blue painters tape does a good job holding parts together without removing (much) of the base paint. Just peel very slowly with the tape folded over itself as you go to minimize paint removal.

Before I glued the fuse halves together, I used a razor to remove the top horizontal rib in the battery compartment. I did this to make room for...Continue Reading
Posted by jmxp69 | Jul 06, 2016 @ 12:37 PM | 6,070 Views
Ever since I saw the Crash Test Hobby Assassin marketing video repeatedly fly the plane into a brick with no more damage than an occasional broken prop I've had two of their planes. The first one was the 36" Assassin. I liked it so much I bought a 55" Grim Reaper. I've flown both planes a ton and both are every bit as rugged as the marketing video demonstrates.

After mixed results trying to get my young son flying with more traditional planes, and after I flew a friend's CTH Albatross, I decided it would be a great trainer to teach my son how to fly. We just came home from the field and the results exceeded expectations. After the hand launch and trim, I handed the radio to Christian. He flew a few laps and gave the radio back for landing. We swapped the battery out and attempted a ground take-off--no problem. I landed right away and turned the radio over to Christian. After two aborted take-offs, he got it off the ground, completed a few circuits, and landed. His first solo!

All-in, he flew 7 2200mah packs. There were a couple of unintentional landings, the last one cost us a prop and a couple of motor screws but the plane itself lived up to its heritage of being very durable. I have about 30 minutes of repair work to do, and Christian will be in the air again.

If you're looking for a durable, competent, slow flying, maneuverable trainer, you should take a serious look at the Crash Test Hobby Albatross. I opted for the Aileron version. After seeing this plane fly today, I know I made the right choice to get my son's skills up to the next level.

The video below is a summary of the build where Christian explains how we put the plane together.

Tech - Crash Test Hobby Albatross 46" Build with Christian (16 min 6 sec)

Posted by jmxp69 | Jul 02, 2016 @ 07:31 AM | 3,932 Views
I've been enjoying my Dynam Warbirds, but the Mustang has been a bit of a challenge. The build was relatively uneventful with a few significant standout items. The motor configuration makes securing the prop and spinner far more difficult than it should be. Reliability is a concern since so little of the prop shaft is accessible to the compression fitting due to the spacing required between the spinner backplate and fuselage.

In traditional Dynam fashion, the landing gear rake on the Mustang makes grass field operations tricky; however, the Mustang is worse than any of the other Dynam Warbirds I've flown including the Corsair, Thunderbolt, and Hellcat. Moving the CG back might help, but the Mustang is a tippy bird.

I cover this and the Big Beautiful Doll conversion from Callie Graphics in the video.

Highlights: Good looking plane although not a fan of the standard livery. Finally found a Dynam power system that doesn't stutter at lower power. Low price for a great looking plane.

Lowlights: The entire prop/spinner attachment arrangement is simply terrible. Motor shaft too short making correct seating of collet impossible. Landing gear alignment while up is the worst of any of my other Dynam planes. Strut skirts rub wheels AND do not sit flush with bottom of wing. 3s power is awful. 4s is a must. Pushrod quick links are terrible (replace with Dubro).

I will keep working on this Mustang to get it up-to-scratch but it is the budget airframe in an economy line-up.

Tech - Dynam 1200mm 47" P-51D Mustang Build Review and Post-Maiden Report (16 min 52 sec)

Posted by jmxp69 | Jul 01, 2016 @ 02:32 AM | 4,132 Views
This video covers configuration and installation of the Hobbyeagle A3 Super II Airplane Gyro paired with a FRSKY L9R using S.Bus.

I haven't had a chance to fly the plane with this stabilizer yet, so I'll reserve judgement on flight performance; however, the configuration software is well thought-out and easy to use. Hobbyeagle also includes the USB programming cable (you cannot use a standard USB cable for this device) and a capacitor which I thought was a nice touch.

The Super II supports multiple mounting options, dual ailerons, and dual elevators if your plane is so equipped.

Stay tuned for the flight review.

Tech - How to Configure and Install the Hobbyeagle Super II Airplane Gyro with L9R and S.Bus (21 min 38 sec)

Posted by jmxp69 | Jun 30, 2016 @ 04:51 PM | 3,955 Views
All I can say is holy smokes. Even after going down to 3s it's still over powered but I'm going to fly it anyway. Stay tuned for flight review.

Tech - Dynam F6F Hellcat SK3 3542 800kv Motor Upgrade and Bench Test (9 min 42 sec)

Posted by jmxp69 | Jun 25, 2016 @ 07:42 PM | 4,359 Views
Finally got the Hellcat out for the maiden. Thankfully it was uneventful, but just like the Corsair with the 500kv motor, power was merely sufficient. The dark/light color scheme of the Hellcat makes visual tracking noticeably easier than the all dark F4U. This is also the first Dynam plane I flew without raking the gear foward. As I fly off a grass field that step has been a pre-requisite for other Dynam birds; however, the Hellcat easily handled grass takeoffs and landings with the gear in the box stock location.

The small ailerons meant docile roll rates. I'll continue adding deflection to improve responsiveness in the lateral axis. I also had a little trouble getting the Hellcat to track straight through a loop but that may be due to a slight yaw. I'll keep working on it.

I guess I'd have to say the Hellcat is between the Thunderbolt (easy) and the Corsair (challenging) to fly. The Thunderbolt's huge wing chord and light loading make it a cream puff in the air. The Corsair's upgraded motor and all dark color scheme make it a little bit more of a handful. The Hellcat's paint scheme, huge waist section, and large fuselage markings are distinctive and significantly ease visual tracking. Overall it flies just fine and I'm glad to have another iconic warbird from Dynam in my hangar.

ParkFly - Dynam 1270mm 50" F6F Hellcat Maiden Flight (4 min 53 sec)

Posted by jmxp69 | Jun 24, 2016 @ 04:57 PM | 4,274 Views
I bought an upgraded Detrum motor for my Corsair and of course the prop nut that came with the Corsair didn't work on the prop shaft I bought with the ugpraded motor (thanks for that one Dynam). While trying to force the issue--and without the proper tools (tap and die would have done it)--I managed to cross thread the nut and one of the two prop shafts.

So....while whining about it to a buddy of mine, he told me to come over and he'd make a few new ones for me. While I obviously knew about the existence of this type of machinery, I'd never seen it up close or in action. I was fascinated and just a "tad" envious my friend had access to such awesome tools.

Anyway, I put together a little video showing how he went about transforming a few lengths of aluminum stock into spares for my Dynam Warbirds. The best part is he has these "programs" saved in his mill/lathe computers and can punch out more parts anytime. While this isn't a plane review or flight video it is related to manufacturing RC parts. I just thought the process was super cool and wanted to share. Hope you like it.

Tech - Machining Prop Shaft Adapters and Prop Nuts for Dynam Warbirds (12 min 14 sec)