HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Apr 02, 2006, 01:02 PM
Fly it like you own it.
_Pattern_Man's Avatar
Canada
Joined Feb 2006
369 Posts
Mini-HowTo
GWS A-10 Warthog Modifications and Upgrades(Retracts,Brushless,glassing,covering,etc)

Well I've done some searching and read most of the A-10 related threads here on reinforcement and power systems. I've decided I enjoy my current brushless A-10 so much, I'd resurrect my battered stock one. This bad boy has been through it all, crashes, breaks, cracks you name it. The stock gear has been torn off countless times, the 300's int he EDF-55's barely even spin anymore and the fuse has been sliced back together almost every 6 inches. LOL it's a mess.

THE PLAN:
Strip it down to the bare foam and build a tough, powerful, aerobatic A-10 with retractable landing gear and Coverlite iron-on covering.

I've already cut open the nacelles (which were already broke off ) and swapped the 300H brushed motors for Fiegao 2045-4400kv brushless motors. I'll be running twin Thunderbird 18's and twin packs of Tanic 1000mAh 15c 11.1V.

I've just finished installing the main gear retracts and linkages and the retractable nose gear.

The compartments on the bottom of the forward fuse have been sealed up and the upper cockpit area cutout and turned into a magnetic hatch where the lipos and ESC's will go.

The stock A-10 is around 14 oz and modified brushless versions seem to fly even as high as 25 oz AUW. So I'm shooting for a finished weight of 20 to 22 oz.

Would anyone be interested in contributing to the thread with pictures and descriptions of their personal modifications they did to their A-10? Would anyone be interested in reading this if I post some pics and follow along while I build?

Just curious if there are still guys modding their A-10's out there.

Thanks boys,
_Pattern_Man is offline Find More Posts by _Pattern_Man
Reply With Quote
Sign up now
to remove ads between posts
Old Apr 02, 2006, 04:13 PM
Fly it like you own it.
_Pattern_Man's Avatar
Canada
Joined Feb 2006
369 Posts
I'll try to spark some interest with pictures. I finally broke down and bought my own digital camera. I've been living in the dark ages.

Here are some pictures of the "Beast" with retracts installed and after doing some sanding to get rid of the old paint.
_Pattern_Man is offline Find More Posts by _Pattern_Man
Reply With Quote
Old Apr 02, 2006, 08:13 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,494 Posts
Patternman, what are the motors rated to? At 4400Kv you are going to be pulling 32A at WOT on the EDF55 rotor. I have been through this already, was using 2030 motors, same size and weight as 150/300 series, I had both 3400Kv and 4400Kv. AUW right now is 24.5 ounces.

3400Kv - 16A WOT
4400Kv - 31.7A WOT

One of my 4400's burnt out, could not handle the current draw. I hit 320watts with these motors. the 3400's pull 200w, and they are rated to 14A each, so I am going to try 2s 1500mah hyperion packs in series this week once I have jerry rigged 12 cells together to emulate 14 volts and tested it on the bench for a brief WOT run.

How heavy are your tanics? I am using one 3s 1800mah 20c Hyperion and it weighs 136 grams and is a brilliant battery in the A10, yesterday sucked all the juice out of one over 8 mins flying at almost WOT the whole time, and was just warm to touch. No vertical performance on 3s 3400Kv, but I also have in the pipeline wemotec minis with hyperion 3600Kv or 4200Kv motors, although I am swinging towards the 3600Kv as it leaves me more play with battery cell count.

Look back through my threads u will see how I built it, glass wing and control surfaces, fuse glassed halfway, nacelles glassed to the fuse with strips of glass that overlap 1/2inch either side. I would leave out the carbon, just use the glass, I have no damage at all landing on grass, not even bum stains!

If you hit the deck at any reasonable speed the CF wont help you, but the glass will, coz it makes a clean break thats easy to repair. I used polyurethane to glass it up, 2 coats, next time one coat and wipe it off as its applied to reduce weight. Also the slope soarer I intend to buy to transfer the winning combo to will be unpainted, saves weight already. Plus I will know where to cut out everything inside before I actually glue the halves together! (yes will take detailed pics)

Your retracts are exactly how I planned to do it, but I was trying to plan a way of fitting a cable system using the real light weight Sullivan cable. I have the GWS "sparrow" ones ready to go for the next model, all I need is the nosewheel gear as its different to the mains, steerable I think??
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Apr 02, 2006, 08:16 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,494 Posts
Oh yeah, when u reassemble your nacelles, make sure the hole for the hex key is pointing outwards, and bore a hole in the foam. Then you can remove the motors without cutting up the nacelles, just unplug your motor wiring and slide em out the back, thats how I swapped mine back and forth.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Apr 08, 2006, 09:11 PM
That thing's operational!
birdlives1955's Avatar
New Orleans/Dallas
Joined Jan 2006
4,706 Posts
Good idea mocca.

Hey guys,

I just have a quick question,

I, like _Pattern_Man, am not a fan of those orange fans......So, I would also like to paint them black. My question is, does this add too much weight to the fans, or cause any other problems like making them unblanced or anything? The thing is, I'm running my A-10 on the stock motors with a 3S li-po right now, and I want to make sure that the performance will still be OK if I paint the EDF55 fans a little bit more pleasant color. Thanks a lot!

-Matt
birdlives1955 is offline Find More Posts by birdlives1955
Reply With Quote
Old Apr 08, 2006, 09:20 PM
EDF rules... :)
AirX's Avatar
Joined Nov 1999
13,566 Posts
Use a black magic marker, wont add any weight. Unsure if the chemical will make the plastic brittle or not.

Eric B.
AirX is offline Find More Posts by AirX
Reply With Quote
Old Apr 09, 2006, 03:56 AM
That thing's operational!
birdlives1955's Avatar
New Orleans/Dallas
Joined Jan 2006
4,706 Posts
Hhhhmmmmm......thanks for the help AirX!

Actually, I already painted the fans with some black "cockpit interior" Model Master's paint and a little brush. I shoud've waited to read this thread again to see if anyone had offered help, and you did so thanks a lot, but I had already painted the fans by the time I read the post. however, I only painted the visible parts of the fans and I tried to use a VERY thin coat on each of the blades in order to garuntee smoothness and low-weight gain. I hope it works out okay. One thing's for sure though, it definitely LOOKS a lot better. Really though, I'm not worried about it, it was really a minimal amount of paint and I don't think it'll cause any problems for the little brushed motors on a 3S pack. thanks again for the help, AirX!

-Matt
birdlives1955 is offline Find More Posts by birdlives1955
Reply With Quote
Old Apr 09, 2006, 07:55 AM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,494 Posts
Matt you can buy the black fan blades pretty cheap, a few dollars each, and soon you should be able to buy the new fan and hub with the screw in the front of the fan to help with retention.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Apr 09, 2006, 01:38 PM
That thing's operational!
birdlives1955's Avatar
New Orleans/Dallas
Joined Jan 2006
4,706 Posts
Oh really?

Okay, cool, thanks a lot for that help mocca! I will definitely check those fans out when they become avialable. For right now, I'm hoping that the painted fans will still work all right. Thanks a lot!

-Matt
birdlives1955 is offline Find More Posts by birdlives1955
Reply With Quote
Old Apr 09, 2006, 05:23 PM
That thing's operational!
birdlives1955's Avatar
New Orleans/Dallas
Joined Jan 2006
4,706 Posts
Hey guys!

I just have a quick question. I have a GWS A-10 with the twin EDF-55 fans and 300 brushed motors. Right now, I am running this set-up with a 3S li-po batt, but I was just wondering...... I have a Promax 370 Cobalt 3726 brushed motor that is made to be able to handle a 2S or 3S li-po batt. If, after the stock motors burn out, I were to purchase an extra one of these motors and put the two Promax 370's into the A-10's EDF55 fans, would performance be better than it is on the stock 300H GWS motors? Here is a link to a data-sheet on Promax motor. Mine is the PMX3726 model.

http://www.maxxprod.com/pdf/PMX37xx.pdf

If possible, it would be great to get a comparison of the amount of thrust that each set-up (both the GWS 300 motors and the Promax 370's)would produce with a 3S li-po. Thanks so much for you help! the reason I don't know this is because I don't have Motocalc and I don't know how to do the calculations without a program like Motocalc. Thanks again!

-Matt
birdlives1955 is offline Find More Posts by birdlives1955
Last edited by birdlives1955; Apr 09, 2006 at 06:22 PM.
Reply With Quote
Old Apr 10, 2006, 06:16 PM
Registered Hack
HACK's Avatar
Joined Aug 2005
232 Posts
Great mods! I would be interested in following your build. You've already helped me visualize the retracts better.

I like to 'personalize' everything I put my hands on, so your build thread is perfect for me and invaulable to my A-10 project.

If I can get something that looks half as good as your's, I'll post it here.

I really like the Magneto-Hatch for electronics access.

Any progress?


Quote:
Originally Posted by _Pattern_Man

Would anyone be interested in contributing to the thread with pictures and descriptions of their personal modifications they did to their A-10? Would anyone be interested in reading this if I post some pics and follow along while I build?

Just curious if there are still guys modding their A-10's out there.

Thanks boys,
HACK is offline Find More Posts by HACK
Reply With Quote
Old Apr 10, 2006, 07:19 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,494 Posts
Matt, your motor is too hot for 3s, its Kv is 4700rpm per volt, with 3s LiPo you will find it will want to pull at least 15-20 amps each, which will cook it pretty quick. It is also 8 grams heavier than a 300H so you will need to move your battery into the nose.

Below is an approximation of calculating your brushed setup:

The 300H is a 3200Kv motor, at 7.2v it spins at 22950rpm unloaded.
In the EDF55 at 7.2v it produces 107g thrust which equates to 17200rpm.
Therefore its efficiency is around 75%.

Your motor is 4700Kv and on 2s LiPo it spins at 34780rpm unloaded.
If we use the 75% efficiency as an approximate base line, your motors should be spinning in the EDF55 at 26085rpm.

This equates to just under 250 grams of thrust each motor.

To get 265 grams of thrust on 3s brushless my Hyperion motor was pulling 9.8 amps on the bench.

I would hazard a guess your motors will pull around 8-10 amps each on 2s LiPo, and I would suggest you use a high quality pack capable of 20c genuine discharge rates to maximise the performance. A Hyperion 2s1800-20c pack weighs 95 grams and is about USD$45.00 in OZ.

At 16 amps constant draw the hyperion maintains over 11 volts in my A10 on brushless.

You will need an ESC capable of 30A continuous to give a good safety margin. You can buy these for peanuts.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Apr 10, 2006, 09:00 PM
That thing's operational!
birdlives1955's Avatar
New Orleans/Dallas
Joined Jan 2006
4,706 Posts
Hey Mocca!

Thanks so much for the help! I really apreciate it. Actually right now I'm running my A-10 on the EDF55's and a 3S li-po, I know the motors won't last very long, but it's FAST!!!!! Actually, today I maidened my A-10 on this set-up, and it flew really nicely until the motors cut out. I was informed that the GWS 300 li-po ready controller would work if I used one for each motor. They did work....for a second. On my first downwind run after a turn, the LVC mysteriously kicked in and my plane got a good mouthfull of dirt and grass. The damage wasn't terrible because I had enough elevator control to keep it from totally nosing in on the grass, but it was moving way too fast for an emergency landing, so a bunch of parts are cracked. I've already got the forward fuse pretty much back intact, but there are a few more repairs that'll have to be done before it'll fly again. Time for some a way bigger ESC!

So the amount of thrust that you brushless motor porduces is only about 15 grams more? Wow that's hard to believe...... Sounds like the Promax Cobalts would be a pretty good replacement set for the stock 300's in an EDF55 A-10 on 2S. I really appreciate your help.

-Matt
birdlives1955 is offline Find More Posts by birdlives1955
Reply With Quote
Old Apr 10, 2006, 10:37 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,494 Posts
Only thing you have to watch is the cobalt motors as I have heard that they can be too hard on LiPo batteries, this would need to be confirmed. They may very well pull way too many amps, you need to install one and run it on its own, get yourself an Eflight meter or similar, its a neccesity when doing this kind of thing.

Sorry for the confusion, the 265 grams I was quoting was just over half throttle! see below..

My little brushless chinese motors are only 40 odd grams, fit in the 150 size EDF55 housings, produce approx 210g each at 7 amps each and are flying a 700 gram A10 very well now I have ESC's sorted. They are also very cheap. They are actually a very good choice for someone wanting a brushless setup without the amp draw, if you build the plane stock, use CF tubing and flat rod to brace, you will keep the weight low. Two TowerPro 15A esc's cost AUD$40.00 here, the motors cost AUD$40.00 each and will run on any 3s lipo. They dont get very hot, and after a 6 min flight flat out 95% of the time I used 700mah out of an 1800mah battery.


My next A10 coming soon will be glassed again, but incorporating different build techniques to keep it light and strong, and will have Hyperion motors which during testing have each produced 430g of thrust on 3s lipo at 17.9 amps.

I have switched to TowerPro brushless ESC's and the first flight I had on them was completely glitch free, plane flew better, fans maintained their RPM right through the flight and I used less current and less mah, cannot argue with that!!
Extreme_RC is offline Find More Posts by Extreme_RC
Last edited by mocca; Apr 10, 2006 at 10:59 PM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold RTF built twin brushless EDF55 GWS A-10 Warthog shschon Aircraft - Electric - Airplanes (FS/W) 0 Mar 24, 2007 07:48 PM
GWS A-10 Warthog Intrepid3 Electric Ducted Fan Jet Talk 30 Dec 07, 2005 05:31 PM
Gws A-10 Warthog Intrepid3 Electric Ducted Fan Jet Talk 0 May 03, 2003 05:16 PM
GWS A-10 Warthog heli-nut50 Parkflyers 2 Jan 10, 2003 08:09 AM
GWS A-10 (Warthog) alterego Electric Ducted Fan Jet Talk 4 Jul 01, 2001 06:11 PM