M41A Bulldog, dual 540 motors in worm gear drop in housings, all ball bearings
08-01-2014, 05:26 PM
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M41A Bulldog, dual 540 motors in worm gear drop in housings, all ball bearings
I have been working on this project for weeks and finally got these 540 motors in a Heng Long 1/16, M41A3 Walker Bulldog Tank. It turned out so good, wanted to share it with you.
Man what a tight fit! Tried several different layouts, this configuration was most efficient, but just barely fits. The yellow gear housings and frames are 3D printed pieces that I designed with CAD. They drop right in and use the original gear housing screw holes. Motors on fabricated 1 1/2" x 1/8" flat aluminum motor rail. Worm gear drives with ball bearings. I had to custom make the Spur gear hubs from several parts purchased from Servo City. The drive axles I fabricated from 5/16 bolts and RC truck axles on my lathe. The drive axles go through a 3D printed yellow button housing with a 16X8x5 Ball bearing for output. What is really cool is you can change gear ratios with motor gear and sur gear. Will play with ratios and see what happens. Just got the mechanical part going today will start on the electronics and let you know how it runs. Would these drop into any Heng Long tank?
What do you think of the setup? Has anyone ever put dual 540 motors in a M41A?
Man what a tight fit! Tried several different layouts, this configuration was most efficient, but just barely fits. The yellow gear housings and frames are 3D printed pieces that I designed with CAD. They drop right in and use the original gear housing screw holes. Motors on fabricated 1 1/2" x 1/8" flat aluminum motor rail. Worm gear drives with ball bearings. I had to custom make the Spur gear hubs from several parts purchased from Servo City. The drive axles I fabricated from 5/16 bolts and RC truck axles on my lathe. The drive axles go through a 3D printed yellow button housing with a 16X8x5 Ball bearing for output. What is really cool is you can change gear ratios with motor gear and sur gear. Will play with ratios and see what happens. Just got the mechanical part going today will start on the electronics and let you know how it runs. Would these drop into any Heng Long tank?
What do you think of the setup? Has anyone ever put dual 540 motors in a M41A?
Last edited by fastmike57; 08-02-2014 at 09:54 AM.
08-02-2014, 09:51 AM
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https://www.youtube.com/watch?v=SA1vb0Ua6vg
Here is a link to YouTube video of the first rough run. It works!
Here is a link to YouTube video of the first rough run. It works!
08-03-2014, 10:22 PM
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You know it is actually a lot slower than I thought. My project tank has 2.5" drive wheels and this tanks drive wheel are about an 1 3/8", so it goes a lot slower. Maybe someone can help me figure out the final drive raito. I always hear guys talking about 3 to one and 4 to one. The pinon on the motor is 25 tooth the spur gear is 66 tooth and the worm drine is a 21 turn. so I fiugure the motor turns 2.64 times for every rotation of the sput gear in turn 21 rotations of the spur gear for 1 rotaion of the axle. So I think the final ratio is 55.44 to one.The drive gear curcumferance is about 4.33", so if the motor is turning 18,000 rpm that is 117 feet per minute at 55.44 to one. but if you went down to a 13 pinion from 25 that is 38 feet per minute. A 19 tooth pinion would be 61 feet per minute. I made room for a 1 1/2 spur gear so might be able to get a 70 tooth in there max. So wide range of gear ratios.
The other thing is the sabertooth 2x12 speed controller is very responsive, it acts like a robot not a tank. Sure with the edmon or regular tank controller it would act more like a tank, but have a lot of extra power.
The other thing is the sabertooth 2x12 speed controller is very responsive, it acts like a robot not a tank. Sure with the edmon or regular tank controller it would act more like a tank, but have a lot of extra power.
04-14-2015, 05:21 AM
#10
That's a wonderful engineering job!
Using 540's on a light tank will fly over anything and the weight looks well distributed and mostly sealed.
Don't know about the plastics, but hope it holds up to the stresses.
Nice job, really. Not a big fan of worm gear style boxes, but I have to say I'm impressed with what you have designed there and looks robust.
Using 540's on a light tank will fly over anything and the weight looks well distributed and mostly sealed.
Don't know about the plastics, but hope it holds up to the stresses.
Nice job, really. Not a big fan of worm gear style boxes, but I have to say I'm impressed with what you have designed there and looks robust.
11-17-2019, 04:26 PM
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Worm Gears in rc tanks
Have you tried a direct bevel gear drive (no spur gears)? I have a M1A2 Abrams tank with the Heng Long upgrade (blue motors and steel gears) and would like more speed.
Last edited by Lew_Zee; 11-17-2019 at 04:28 PM. Reason: Add info
11-17-2019, 04:43 PM
#12
FastMike hasn't posted in a long time and this thread is over 5 years old. He has an Ebay store and doesn't have these gearboxes listed in it anymore so I don't think he makes them anymore, but you can print them yourself minus the metal parts: https://www.thingiverse.com/thing:2725197 Not sure where you could get the metal parts needed to finish them. The bevel gearboxes that are made for our tanks are expensive. ETO makes some and https://www.modellspiegel.com/.
11-17-2019, 08:32 PM
#13
I had one of the Fastmike worm drive gearboxes (since given to RichJohnson here on RCU to mess around with) and I can tell you they are nowhere near as fast, powerful, quiet or reliable as the 3:1 upgraded HL or Taigen gearbox running 390 motors at 7.2 volts. The worm drive gearbox was cool to play with and look great in my Abrams but just did not offer anything special even with 390 motors.
11-18-2019, 10:51 PM
#14
ETO makes some and https://www.modellspiegel.com/.
https://etoarmor.com/?product_cat=et...ns-made-by-eto
My units are for Tamiya only but others are available on special order. Installation of my units is simple with no modifications of the tank lower hull beyond two additional 3.5 mm holes in the hull floor, the additional holes keyed off two existing Tamiya transmission mount holes. Detailed instructions for installation and the simple location of the two additional holes are included, with photos.
