Imex-Erik

Hello fellow tankers,
First, let me start by saying this is not a REAL build. Nor is this your average build. This is just a fun project I finally got some time to do. I have wanted to do a brushless motor setup since I started working here but as always I am short on time. I did find a few things like brushed to brushless converters and such, but they were for low amp applications and even 5A was too much. I could of had bossman buy me an elmod or something equivalent, but why not make a brushless tank that anyone can make? While I'm at it, why not explain how to do it and what to use? Enter project brushless....

I started with one of my Tiger 1 plastic tanks. I do have a few and the weight is minimal while still providing a metal chassis to work with.


I did add metal drive wheels and our new 2pc screw together type idlers we just redesigned. After that I gutted the tank. I removed the stock gearboxes, motherboard, smoke unit, and switches. Then I ground down all the nubs on the motherboard plate that is inside the Tiger 1. You are left with a empty tank. Forgive me for not having a picture of this, I figured it wasn't needed
Next it was time to find some brass gearboxes and remove the motor and pinion. The pinion we will reuse later. I then found a 28mm outrunner motor (2838 motor, 1200-1500kv I cannot remember) and bolted it right up. 20mm bolts up directly, while my 28mm motor had 2 different mounting arrangements. The 28mm motor bolted directly up, but the pinion needed to be drilled out a bit to 3.175 to match my output shaft on the outrunner. After drilling the hole out, I ground a flat spot on the shafts for the pinion to grab on to. The result looks a bit like this:


If you notice you will actually see you have MORE room than with a stock motor. The choice is yours here to pick your KV. Outrunner motors are great with torque, so best to pick a low KV if you are looking to get some more scale speed. I would suggest around the 500kv rating for 2 cell lipo. Anyways, now for the install....


As you can see I did install two crossbars to help with flex. I also installed two of the same ESC to match with the same motors. Now comes the tricky part... getting it to work with one receiver. There are a few ways to make this work, the two I recommend are to use two ESC with no BEC and power the receiver with a separate battery, or use two ESC with BECs and disable one BEC. I chose the second way as it is the easiest and doesn't require a second separate battery (I dont need 3 haha). So to do this you must hook one ESC up as normal, but the second ESC you must cut the red wire going to the receiver. This needs to be cut to stop 2 ESCs worth of power going to your receiver.



This will be your end result. I have since taken the gearboxes out and straightened them since this picture. I turned the motor plate upside down and screwed a screw through the bottom plate to help the gearboxes seat in position a bit as reaching the hole I screwed is impossible from the top. This makes the gearboxes quite solid now and I am sure 3 cell and even 4 cell would not budge these guys

I am uploading a video now, but it is over 1.5GB so it might not be up til tomorrow. Once again, this is not scale nor is it meant to be! This is just a fun project, more of a test for brushless motors than anything else. It is quite fast and will drift like a car. Future plans will be:

• New radio system 2.4GHz with mixing
• Look into getting other stock functions working, and the effort involved.
• Higher KV outrunners
• Bigger or different ESCs

I might take it out to the track with me the next time I go, but those 1/8th trucks are vicious. I might have to wait til I get a new radio system first Well I hope you guys enjoy!

Imex-Erik

First video here: https://www.youtube.com/watch?v=6IAe...ature=youtu.be
I will get some more video probably this weekend if I find some time (my gf's bday is this weekend) else I might take some video outside the warehouse. It has quite the pickup outside and will wheelie on 3 cell For now it is quite enjoyable on 2 cell, so I think I might leave it there for now. Estimated top speed is close to 20mph right now. I was aiming for 35ish, but currently I'll have to wait until I get a new radio before I go faster.

Green Amphibian

I used brushless motors in my LVT's. They are really a trip on hard surfaces and work well in the water too. I found that I had to go to steel gears because the brass ones did not hold up very well.

Herman

Ex_Pat_Tanker

I must admit that was my thought too - I've bent the shafts in those gearboxes with the stock 360 motors

Now, if we could get them there motors fitted to the 4:1 steel gearboxes, and somebody comes out with a controller that battles with Tamiya and its clones... ?

Strato50

This is cool & ambitious, looks good Erik.

The advantage of big stubby outrunners like these is the smooth application of low speed torque. With the right combination you can get a tank crawling at slow speed while looking realistic & now bouncing around.

...I also assume it's easier on the battery with most setups as brushless is incredibly power efficient :P

MAUS45

OK, just watched the Tokyo Drift Tiger I. What a Beast!!!!!

mustclime

fyi.....I found this on youtube years ago...


http://www.youtube.com/watch?v=KuPTvwP61uA

grass drifting ftw

Imex-Erik

Yea my first choice actually was the steel gears. I started with the 4:1 steel gearboxes (to my surprise is 48 pitch) and inrunners but did not get the results I was wanting with 4:1. I also got nice 28mm motors to fit on the High/Low gearsets with no modification to the gearbox, it was direct bolt up. I will most likely return to the steel gearboxes later but use outrunners to get the torque needed for heavy tanks.
I tell you what, I put the gearboxes through hell and so far no issues. I do have lots of replacement shafts for the brass gearboxes just in case, both long and short. As for fitting the steel gearboxes, that will come soon, I am awaiting pinions now
Yes, at a reasonable KV you could have a very efficient, quiet, and powerful setup, all while maintaining scale speed. Then with just a few bolts change to something a bit faster for outside. Brushless is a bit easier to tune and also find motors and specs for. But yes, the problem is finding tank controllers for it Elmod is very expensive and is the only board I know of atm that supports brushless output. I would be very interested in trading for one, if you have one with brushless output and are willing to part with it for a trade please PM me
Haha, that was just the first video! I am getting much better now. When the boss was watching I did almost a full 360 in a drift. Where it really was nice was outside in the sand. The extra speed made it kinda toyish, but very enjoyable as a speed nerd.
Yes I did see that, I searched around forever on youtube but no one really documents the motors in the gearbox, just the completed build. I wanted to show a bit more detail of the motor and application of it. I will do a more detailed video when I do the steel gearboxes with new motors I will open and install the motors on camera to show how easy it is.

Imex-Erik

Project brushless has taken a large turn. I felt I should update everyone to my new plans for this tank... This will be an outside rough driver. It will be the one I take to the track, and also the one I take mudding and more with later after I try to waterproof it
As of now the project tank has changed from a Tiger 1 to a Stug 3 platform. I have had my broken Stug 3 waiting since Feb. to be fixed and be used for something, now I found the perfect option for now. The Stug 3 was a metal version so my gearboxes would fit fine, as well as the rest of the electronics. I went and swapped them around and with the shorter barrel I now can climb a bit steeper angle. Since I currently do not have control of the other functions of the tank (yet) this was a big deciding factor. I went ahead and painted it the ugliest color possible as it was a few colors when I patched it back together. I figured black would be great, and we could call it the SWAT tank lol.
My next plans are to find a mixer for the radio. I do now have a better way to control things inside of the tank, but I do not think I will put a sound system in the basher. It is too much wiring and will be difficult to waterproof later on. I also have a few of the brushed to brushless signal converters coming to me from HK as well to see if those will work too. After that will be changing the gearboxes to either the new 3:1 steel we just got or the 4:1 steel gearboxes. This will allow me to run some really long can 28mm (or 380 motors) brushless motors. I saw a 2874 motor that should give some very impressive stats. Next will be to find some waterproof ESCs, a single big battery, and to hook up the firing and elevation if possible with the lack of space I will have.
Everyone at the local track LOVES the tank and I honestly think I spent more time talking about it than actually driving it. I even used it to flip over a few cars. The hobby shop owner was laughing up a storm and loved it when I let him do a few laps. After I get all the internals done I will have our painter redo the tank and make a NICE paintjob for me with SWAT wrote over it and a few other things.

Imex-Erik

Project brushless is now two separate tanks! The Stug III is still in commission though I have had a motor issue overheating on 4 cell Right now it is awaiting funds for some new motors. As much as I like the outrunners the high RPM of the inrunners makes a large difference in torque at the tracks. With the limited space of the Stug chassis I might be stuck with outrunners for now. While I was looking at that I figured it was time to look back at the Tiger 1 chassis I originally started with...
I knew I wanted the steel gearboxes and inrunners. That much I was sure, however the type of motor was a difficult one... 28mm motors fit just fine directly mounted and you could get all the way up to 60mm depending on how the wires came out of the can! I didn't have any matching KV 28mm motors sitting around so I figured why not 36mm motors?? Well I did happen to have a few 3650 3000kv brushless motors sitting around from VRX Racing and was sold! The problem with these big motors (540 equivalent brushed motors) is that they interfere with each other's mounting positions. The only way to get the 4:1 to work was to actually remove the first reduction gear and use that space where the gear was to mount a motor. Then mount the other motor in the Mid position you see on the low profile gearboxes as close to the front of the 1st reduction gear possible. I actually have to go back and try to get it a bit lower as it is interfering with my top hull currently and I'm not happy. Then you use some nice 120A 1/8th scale ESCs and a receiver and you are all set! This new setup is for 2-4 cell only but I will be using at 2 cell for now. The KV rating was more than doubled on the motors but the voltage was cut in half as well so it is about the same speed but with TONS and TONS of torque. Also at this voltage I can creep very slowly or get up to about 20mph very fast! Remember these motors were on a brushless SCT so they are VERY happy to go fast. I will take it to a new local hobby shop near me I'll be visiting this weekend and get some pictures for you guys! This thing is SUPER fun to play with!

Imex-Erik

Ok so yea.... a bit ugly with the giant purple motors, but we now have enough torque to walk a medium sized dog! This is the original Tiger 1 I started with, I just cleaned it up a bit from the last few uses/tests. The tank now runs fine with dual 3650 brushless 3000kv motors from a 1/10th SCT. It has dual 1/8th 120A ESCs and is for the most part waterproof.

https://www.youtube.com/watch?v=DJe5NjYoO7s https://www.youtube.com/watch?v=hLYSq3kFK1M Next my goal is to get the top back on this guy (more gearbox modifications). After that I will look into more scale speed motors, but I do want to keep the 36mm motors. The amount of torque on these guys is insane. When offroading, the only thing that stops you is weight. If the grass gets too high it lifts the chassis up off the ground, other than that.... it is pretty unstoppable. I will look for some motors in the 800kv range instead of the super high KV ratings now. Next week I'll try to get some video at the track, this weekend I had to take a swim in the pond (yea no joke, neck deep in a lily covered poop smelling pond) to retrieve one of my cars and had to leave early The car still lives though!! It sunk to the bottom of a pond for a few minutes before I jumped in and I didn't even let it dry and it still runs perfect!