invertmast

My Feedback: (23)

Your only option is either fly it as is or cough up the money for tires and brakes

No mixing in your radio or external Pcb board will ever make a single function esc (aka, low throttle to high throttle) reverse two of the power wire's going to the motor. The only way to get that to happen is to use a reversing esc for a car

kahloq

Yeah I know. And there aren't any reversing car esc's that run on 6s or could turn the 16x10 prop since most car motor shafts are very small use for having a gear installed and have rather high kv. There are boat esc's that can handle the higher voltage of 6s, but, no way Im carrying a water fed system to keep the esc cool...that would require more weight then just putting brakes on the wheels.
The only other option really is to have the rear motor set from the get to turn in the direction to give opposite thrust and it would only function when you flip the switch. But then you're not getting the benefit of that motor during flight

So...looks like coughing up the $400 is my only recourse. BTW...a pcb board type device could be used as others have scratch made something and done it on rcgroups, but only on power systems of 3s or less.

vertical grimmace

My Feedback: (1)

I think I would try to fly it and see how much you can slow it down. With full flap, that should help shorten the roll out. Dropping the flaps was not an option during your fast taxi runs. We have that huge runway, and you will just have to be low over the threshold. At least being electric, once power is removed, the props are just drag.Different than an idling engine.

kahloq

Ive already submitted an order through Robart for a complete brake setup including the wheels. These brakes will also fit the tires on my airworld me-262 if I find that the the do-335 lands ok and can stop without them. No idea how quickly robart will get them shipped out, so ill probably end up trying to fly it without them anyway.

vertical grimmace

My Feedback: (1)

Pics?

kahloq

Email from Robart says my brakes and wheels have been shipped and should arrive the 13th. Problem is, the 13th is Saturday.......so maybe FedEx will deliver it on Saturday. If so....ill have time to get them installed before Sunday when plane would make another appearance at field. If they don't arrive Saturday, I may not even bring the do-335 to the field......I've got plenty of planes to fly and there's no super rush to get this test flown this specific weekend.I'd much rather feel comfortable I can get the plane stopped having already installed the brakes then wish in hindsight I had waited to test fly once the brakes were installed having run off the runway causing damage without them.

jimkron

Correct. Don't rush.

I bought the expensive Sierra retracts and during taxi trials one of the wheels kept locking up. I scratched my head on consecutive Saturdays trying to figure out the problem. Turns out I needed a different axle grease. They've been perfect ever since. Moral to the story...take your time.

The flaps, retract, brakes, motors, lipos, steering, plane balance, etc need to work perfectly before you give her full throttle.

Also, My brakes from Sierra had a very cool proportional valve. I hooked it up to the elevator. The more I pushed up, the more it gripped. Very nice...but brakes will add more weight and will require a whole new balancing.

One final thought...I'm a chicken ****. I never maiden my own planes. I'm lucky to have some very good warbird pilots at my club. I find the team effort works for me.

jim

ps. Be aware that the color of this beauty makes it hard to see in the sky. It silhouettes like crazy.

vertical grimmace

My Feedback: (1)

Kahloq, did you get the rear motor figured out? My phone wont charge and will get new one this weekend. Not sure if you have txt me or not.

kahloq

The rear motor was just a problem of a loose/broken solder joint from the factory. Its fixed now and there won't be any mixing going on to limit motor spool up. It will be simply on a y harness with the front motor since ill need that channel for the brakes

kahloq

Edit...seems pics are working again.

kahloq

Seems pics are working again.

Someone on RCG had the idea of using a heli setup with collective pitch control to reverse the pitch angle of the prop blades to do what I had mentioned earlier about reversing the direction of the rear motor to act as a thrust brake.
Honestly, it could be done, but both front and rear motors would have to have the setup as there'd be no way to reverse the rear motor's blades and still have a one direction motor setup up front.....since on a heli with collective pitch ability....zero throttle is the middle of the stick, not at 0 position.
Could be done though and would work well say with an equivalent power 160 setup, but using a heli motor/gear. Due to the gearing, the power requirements would be less. Instead of a 12s up front for my rimfire 65cc, it could be a 6s heli motor(from like a t-rex 600) and use the two 6s 8000 packs in parallel vs series.

Too late for me to do that on mine, but an interesting idea none the less. Might have to try that on a test bed plane at some point in the future.

Here's a video of a guy that did it on a large 3D plane. Check it out:
http://www.youtube.com/watch?feature...v=0IDDWN-qTBI#

vertical grimmace

My Feedback: (1)

Uh, yah. That is really not a practical solution and asking for trouble! I would bet at our field, it would be fine without brakes, but we will see. If needed, I think you went the right way getting the Robarts.

kahloq

So do I.....and can always use them in my airworld me-262 at some point as well.

kahloq

Brakes arrived today Trying to get them installed, however, having to do some modifications to the ESM strut.....just some grinding off of some aluminum, but, we'll see. Doesn't matter if its done by tomorrow or not since its going to be rather windy...so it'll give me time to get it all buttoned up.

vertical grimmace

My Feedback: (1)

I will be in shop most of tomorrow if you wanna stop by. Got lots to do on Tripe. No flying for me. Oh, got phone to now! lol

kahloq

Yea...Ill stop buy Ill bring the electric start system for the gasser motor going in the Spit so you can look at it. What time you gonna be there?

vertical grimmace

My Feedback: (1)

after 3

kahloq

Pics of the brake installation

kahloq

I had to replace the ESM axles with 6mm bolts from Home Depot as the ESM axles weren't long enough and too small diameter wise after the strut attachment point.
No big deal though. The only real issue was with making room for the brake stop pins that keep the assembly from turning inside the wheel drum when rolling. Had to grind down the ESM aluminum strut some to get the stops to fit.

irocbsa

My Feedback: (12)

Nice work! Looks great, but it's absurd that they cost $400. [X(]

kahloq

Well...the brake kit and electronic air valve etc doesnt cost $400. The entire brake system is like $260 with air tank, brakes, air line, fill valve, electronic proportional actuating valve and tubing. However, I had to buy the Robart 4.5" wheels because the ESM wheels I have arent designed to work with brakes. No one else makes brakes for 4.5" size wheels that I am aware of except Glennis and those would be ridiculously expensive. I was informed of another place that makes brakes on RCG, but they only go up to a 4" wheel and this plane takes a 4.5 and could fit a 4.75 without mods.

So...rather then trying to retro fit something that may not work anyhow, I just coughed up the dough and got what will work.

vertical grimmace

My Feedback: (1)

The install does look good....But!........I would be a little concerned having the wheel bushing turning on the threads of that bolt. I do not think it will last. The threads will machine away the bushings and begin to roll rough after a while, possibly hanging up.

irocbsa

My Feedback: (12)

Would some heavy duty shrink tubing over the theads work to keep the bushing unharmed until you can find more adequate axles?

kahloq

I had the same concern as VG about the threads of the bolt against the bushing. I think grinding down the threads gently and then wrapping it in tape should work fine. Ive used painters tape as a spacer before to get a wheel hub to fit an axle and it worked well without long term issue.

Ameisenbar

Hi Kahloq, That doesn't sound like a very sophisticated solution to me. Iwould probably make an axle myself from a piece of high tensile steel bolt, but then I have a lathe here. One way to get a plain shank for things to run on is to look for cap head screws. One you get to a certain length, usually about an inch or so, they start to have a plain shank portion. With a bit of luck you can sometimes find one where the plain part is the length you need. There will then be a bit too much thread on the end, but you can cut that off with a dremel or similar....run a nut up the thread first, and file the cut clean before taking the nut off.

John