Do you still ride a horse to work?

Hope that was not written intending a sarcastic tone, because Rich is a good guy with years of experience in the r/c world. If he prefers NiMh so be it he has his reasons and they best meet his needs. You do not prefer NiMH, so be it thats good too. I use use both, but actually prefer NiMh for most of my R/C tank applications as 2C 7.4v LiPos are to low voltage and 3C (11.1v) are to high. For my set ups the sweat point is 9.6v and that means NiMh batteries. You will find that there is not a one size fits all with tanks more so than with other R/C hobbies. Some guys like slow with torque, some high top speeds, some like the middle ground not to slow but not to fast and all might be running the same model tank. Some have very heavy tanks some have light weight tanks. One has to find the right combination of power, motors, gearbox, track, sprocket, road wheels, suspension, spring rates all to achieve THEIR end goal. For some like you the power aspect is LiPo and for some it is NiMh. I respect your R/C background, but please understand other have extensive R/C backgrounds too and might disagree with you. That does not make you wrong or them right it means you are both looking at things from a different point of view. Trust me I am one of those guys that does things a bit unconventionally / outside the box and have had a few counterpoints to my way of doing things brought up.

But the 54 Willys is harder to get parts for! ;)

I need to post some progress so this thread can get back on target... :) Got my motor connectors and M3 mounting screws for the motors so I can finish mounting the motors/ESCs. Have a few parts from overseas on the way also that have cleared customs in the US so they should be here this week sometime. I want to track down a Henntec track tensioner. ETO is showing out of stock. I guess I'll have to order it direct from Henntec.

The metal road wheels, suspension arms, idlers, and rubbber/metal track is the package due here this week... Not sure what brand the track is.

Was going to say I think I know what your tensioning solution is...you removed the bottom stops on the suspension arms? I also ordered some upgraded suspension springs so I will see how well the tracks stay on and go from there. The point of making the chassis as stiff as it is was to reduce any flex that could cause the tracks to come off.

No NOT the suspension mod. Though it works beyond belief, it is more complex and gives the Abrams a more athletic stance. I am referring to something MUCH simpler, the use of a M41 idler wheel. The metal/rubber tracks when installed with / on an Abrams idler to the same link count as the plastic HL track tend to be about 1/2 a link to long depending on the brand (there are really only two brands, but one is sold under many names). It works if driven gently, but then that is no fun. If you attempt to go one link less the track is far to tight and one link more it it far to loose. The M41 idler wheel is slightly larger than the Abrams idler and as such mimics the movement forward that a tensioning system would provide for taking up the extra 1/2 link track length, but at a fraction of the cost and complexity. I now run them on two of my three Abrams (I can post photos if you would like) and if I was not to point them out they would almost never be noticed as they are 90% hidden under the side skirts. I have NO issues with loosing metal/rubber padded tracks (also running metal road wheels, suspension arms and sprocket) except in the rare instance where a large rock or other large debris get between the sprocket and track while slamming the tank into a hard turn at high speed. But when that happens nothing would be of help anyways.

The springs, road wheels and suspension are all great buys. In regards to the springs, I have found they are only needed on the #1 and # 7 suspension arms. These are the two arms that have the most impact on the Abrams track retention. Using the heavier spring settings or heavier springs on all the suspension arms makes for a very bouncy tank, even on heavy ones like mine (11+ lbs). The stiffer chassis is more of a myth (based on my experience with testing on side by side HL Abrams) as it plays very little into track retention on the longer modern designs of tanks with their factory screw together "unibody" like hull mounting system. In my experience the stiffening only adds weight and little else (the last statements might light a fire with some and are a subject for another thread discussion). Vastly more important is having road wheels that are tight with very little "wobble", properly adjusted springs, a sprocket with retention rings and through hull drive axle bearing supports. That said given your extensive hull mods and the power plants you are using it will be to your benefit as you will have loads of extra power to overcome any added weight. Plus I like your design it is very a clean and should prove incredibly strong.

Thanks for the tip. I'll probably order a set just in case. Tracks tend to stretch some with use also. Yeah, I had to increase the tension on my paintball combat Sturmtiger on the front and rearmost road wheels to keep the tank from sagging so I know where you are coming from. Making them stiffer also helped the track tension on the Sturmtiger although it's track is so stiff that it would take an act of God to get it off the sprockets. I guess I tend to overbuild my tanks so beefing the chassis up just goes along those lines. If it never breaks, I never have to fix it... :)

Actually made more progress on the Abrams. Did my first runs with all the metal parts (tracks, wheels, idlers, sprockets, and arms). Everyone was so concerned about the brushless motors being too fast. I think they are too slow, but I'm running at 7.4V for the tests. Running a 3S LiPO might give me the speed I need to get it up to scale speed. I did discover that the brushless HK Car-30A ESCs I'm using aren't good for tanks. They have a minimum of 6% neutral/deadband that can't be programmed out. It's adjustable, but not to zero. Causes some control issues when using single stick driving. Just ordered some non-programmable ones that look promising. All of the programmable ones I found had a minimum neutral setting. I know it's the ESC and not the TCB since I ran the ESCs directly off of the receiver and bypassed the TCB to test.

I was going on the specs of the first guy that upgraded his DKLM gearboxes with brushless motors. He drilled new holes. I didn't want to drill any new holes so I went with 540 sized motors to avoid that. He used 1500kv motors. I'm glad I went with the 1650s. They were cheaper actually and seem like they have plenty of torque. I couldn't get the stock motors to fit in the Abrams which is why this whole experiment started. The brushless motors seem smoother and quieter than their brushed counterparts. My new ESCs arrived today. Just need to source a decent 3S battery now for testing. Just make sure your ESCs don't have a deadband you can't program out. That's why I'm trying another set.

How/s this working out? Which ESC did you end up going with?

The new ESCs were worse than the Hobbyking Car30A so I've gone back to them. I actually just installed a Henntec idler system in it the other day since I was shedding tracks. Not because of speed, but because the front idlers seemed to move around a lot. I still haven't been able to determine what is causing the forward/reverse delay or lack of response at times. I need a couple of longer bolts for the Henntec to finish it's install and then some more testing will follow. I bought a second set of sprockets with a track retaining guide to use also if I still have issues shedding tracks. I also got some 3S LiPos to run the tank on and I think I heated up the battery switch too much trying to solder new battery leads onto it. The joys of coming up with new solutions... If I can't get the ESCs to act like I want I may try to use a brushed 540 motor on the gearbox since it would be shorter than the 550 that came on the gearbox. It's the end of the year and my work is project based so everyone is trying to get their projects done by mid-Dec when my company goes on mandatory holiday. Haven't had a lot of time to play with my tanks as of late. Hoping I'll get some time to figure out the issues over the holiday break.

I know you said you tested the ESC's strait off the receiver and bypassed the OP board but I thought I'd mention that I had some similar driving behavior using the OP board. The tank wouldn't change direction for a second or two. It wasn't until I tweaked the driving mode (1,2, or 3) and the momentum/inertia/nudge settings that it started to give me instant reverse or change of direction. I also changed the transmission settings so there wasn't a delay at all. I'm using Taigen 390's, not brushless. Don't know if that helps you or not. Would sensored brushless motors make a difference?

Not sure. This really is my first foray into the brushless world. I have played with the settings on the TCB board also. How did you set it up to remove the delay? I've been seeing the delay on different ESCs and motor types (brushed and brushless). I love the TCBs for what they are, but there is a learning curve to them. I backed up my config the other day before an update came out. After the update it deleted my config. I thought no problem I'll just restore it. Then the config wouldn't restore due to the difference in code. Now I have to set all the settings back manually. I've been trying to use driving mode 2 with zero nudge or inertia and the transmission set to zero. It didn't produce the results I was looking for. I guess I've gotten spoiled from my large 1/6th scale tanks with the fancy ESCs that do instant reverse and direction changes.

There are some VERY nice multirotor ESCs that can do much, much more than most of the cheap ESCs out. Look for BLHeli_32 ESCs. They can be programmed to be 3D mode which is good for tanks and has everything from adjustable/auto timing to current limiting built in for less than $10 each or so. I use lots of BLHeli_S and BLHeli_32 ESCs and I think you might have a much better experience with it. However unless you have a $20 flight controller you will need an Arduino to program them. As far as I'm aware the BLHeli_32 ESCs are some of the best out for the general public. Let me know if you are interested, I would be happy to help with this.
I have x2 3660 motors at 3000kv with x2 120A 1/8th scale ESCs I pulled off a RC car here and they are on 3:1 gearboxes and it is WAY too fast on 4S but hilarious to take to the track. I have it still sitting around somewhere but I had nothing but trouble with idler wheel arms and such. I keep telling bossman people want a nice off road basher, he might actually be coming around to it too! I posted a video a while back of me drifting it in the warehouse, it was kinda neat. I'll see if I can find the tank, pretty sure it is in the garage at home somewhere... For the ESCs, what kind are you looking at?

Ok so please forgive me for possibly the dirtiest thing I have ever posted on the internet haha. Found it deep in the garage, been a few years since I had this one out. I seemed to have removed/lost one of the ESCs at some point too... Also is a picture of a (very used) flight controller and x4 30A ESCs in one board :) The mounting holes are 30.5x30.5mm and it can be used on a tank technically with all kinds of adjustments such as max speed and expo. The problem is there are no sounds at all but operating other things like servos are easy and you also get a built in OSD if you FPV it. If you really are looking into brushless I would like to help, I would also be seriously interested in the performance difference between brushed and brushless per dollar and I can make a setup that makes it USB plug and play for software so you can change settings on the fly (or even with your phone actually).
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