T-maxx going brushless...tips?

[J3110]

Howdy.
So I just got a new E-Maxx(3905) and I'm pretty stoaked with it.
After my old T-Maxx decided the one-way bearing didn't wanna grip the crankshaft anymore, I shelved it for a bit(5 years).
I knew I was getting the new E-maxx no matter what, so I made a deal with myself that if I got the new one, the old one wouldn't go to waste.

Let's face it...I suck at dealing with nitros or the TRX pro 15 sucks. Either way, I have a solution...I hope.

I've asked around a bit and it sounds like this should be rather straightforeward:

1.) Yank all the nitro gear out.
2.) Install brushless motor, esc and batteries.
3.) Go!

So, that's it, right? :)

So far, I have a pair of twinforce battery trays on the way. Figure I'll bolt those up under the chassis.
I also went with the E-Maxx combo from starluck RC which should take care of the motor, ESC and BEC. Unfortunately, it's one of the 540C cans, so I won't be able to use one of those nifty rcmonster heatsink/clamp gizmos...perhaps if I decide to do the 3905 one day.
The T-maxx already has the servos and RX.

The reason I'm posting this thread is because I anticipate needing some help and I read this place is the best for these kinds of projects and general RC monster-type advice.

I figured I would use the reverse lockout on the ESC and then just use the standard reverse that comes with the t-maxx via the third RX channel.
I also plan on making use of the mechanical brake to save the motor even more abuse.
All I know about the MM ESC is that it has a proportional brake, but I am hoping that I'll be able to swing something to make the servo at the very least, take most of the braking load.

Someone mentioned I'd need to also get a 32 pitch spur for the tranny. I am guessing that's because the pinion which I don't have yet(but will probably come with the motor...or not?) will also be a 32 pitch. At any rate, what I gather is I wanna use the same pitch on the spur and pinion...k, got it.

Not sure about gearing, but I'm not in a huge rush, so I've been taking it one step at a time since there isn't really a bluprint for doing this.

Any advice or help would be much appreciated.

Jelo

[JERRY2KONE]

You are correct about the RCMonster site being the best for e-conversions. There have been quite a few done in just the last year that are easy to find if you pan through this site. Plus there are a few guys on here that have done just that and I am sure they will pop in and give you their advice. Welcome to the number one RC site and have fun doing your research and getting your e-conversion up and running. Good luck with that.

[lincpimp]

I am also doing a tmaxx conversion, heres my thread, have a look and feel free to ask any questions.

T Maxx Conversion Thread

[J3110]

Any ideas on where I can get a motor mount for the Feigao 540C-7XL?
Being that it's got cooling fins, I'm planning on making my own motor clamp using some threaded rods sheathed in carbon, aluminum locknuts and then a strip of aluminum at either end of the motor.
Ideally, I would use a motor mount that has tabs on either side of the motor with drilled and tapped holes for the threaded rod, but I may be asking a bit much there.

My guess is a 1/4" L bracket-type mount would work. Unfortunately, I don't have any decent metalworking skills/tools and my experience trying to work aluminum with a dremel has been less than satisfactory.

I have some thinner aluminum that I could chop with a dremel, but my fear is it'd be too thin and bend.

I saw some posts about a dude named ColdFusion who has had some motor mounts made and was thinking of asking if he could have a custom mount built.

Any other keen ideas?

[JERRY2KONE]

You could try calling Mike here at RC Monster to see if you could work something out with him. He has access and skills for making dreams come true with RC CNC issues.

Also you can still try DIY and see what you can come up with. Working with aluminum is a little tricky if you have done it before. It is very soft and requires a little patients. Don't depend solely on a Dremmle tool, but they can be very useful for tinkering with manufacturing small RC parts. The main thing is not to get in too much of a rush with your project, hence forcing shortcuts. Once you cut things the way you like them it will require some grinding, sanding, and polishing with super fine sand paper (1000 grit) to make it look professional enough to meet your own standards. You won't really know what you are capable of unless you give it a shot. Aluminum is not that expensive for experimenting with, and as the saying goes "if at first you don't succeed, try try again". Honestly you may surprize yourself. Good luck with that.

[J3110]

You've encouraged me.
See what I can scrounge up at the local junkyard and go at er with the trusty dremmel.
I do remember trying to grind at a cooling head awhile back and the aluminum kept gumming up the grinding stone or sanding drum.
Should I be using carbide tips or something? There's gotta be something that works better and isn't a cutting disc...I'll google it.

Danke-

[JERRY2KONE]

I am glad to hear that. I have been using one of the newest Dremmel cutting wheels myself and it seems to work ok for me. It is a little bit heavier than the usual ones in the kits. Just about anything you use for grinding or sanding will gum up over time or if you use to high of a speed. You can either clean them off or have spares to switch out heads. Like I said it tends to be kind of soft and a little tricky, but it all works out in the end. Using a mill of drill press works a little better in some cases, depending what it is you are trying to accomplish. There are a few guys on here that do a lot more aluminum work then I do, so maybe they will chime in and give some supportive advice. Mike, Metalman, Linc, Serum. You guys are the master in here. What do you think???

[lincpimp]

I am far from master status! But thanks for grouping me with the greats Jerry! I am flattered!

I usually cut al with a fine tooth metal blade in a std cheapo reciprocating saw, soem people call it a jig saw. You could use a sawzall, but they are not as handy as the jig saw, the blades are too wide to make good cuts in tight areas. Variable speed is handy too. Get some good metal files, they are very handy too. And a drill press, even the 50 dollar harbor freight kind are invaluable. Also buy a good set of drills, and some cutting oil while you are at it. I also have a bandsaw, but mainly use that for cutting plastic, it is not the best tool for cutting al or steel.

I do intend on buying a small mill, or combo machine (mill and lathe). Small ones can be had for less than 500 bucks and that would most likely let me hone my machine tool skills (which are non existant at the moment!)

Paitence is a good thing for doing metal work, Jerry is right about that one. You will have to make a few items and then you will get better, at least I had to do that!

[J3110]

Oodles of weasels....man, I was just thinking about that on my way home from work today when I heard this noodle commercial on the radio.

Cool, so get a drill press and some good cutting gear.
Check:


I jest...that's not mine. :)
...but I have seen the aluminum metalworking live and in the shavings, so I know what you mean.
Home depot, here I come.

[JERRY2KONE]

Now that is just sick. Someone is having way toooooo much fun there. Nice shop whom ever it belongs to. I wonder how much time is spent playing in that little hole in the wall.

[J3110]

I've spent days down there prior to each of the final 3 seasons of battlebots.
An old friend of mine used to run a superheavyweight bot asked me if I wanted to help him out. Sounded like fun, so I figured why not.
I'd help him tear it down, clean it, solder stuff, put it all back together and operate the weapon during competitions.
He spent most of his time doing complex math and milling heavily lubricated 6061 and 7075.

The jet was just over 10 grand, I think...
DooAll here:

was about 30...grand in parts and materials.
The speed controller alone was about $2,500.
375lbs driven by 2 wheelchair motors in the trackpods being fed with 6 plates of 18x3000mAh panasonic nimh C-cells.

It actually ran better on the older gel cells, but they were fairly heavy.

Anyways, to bring it back around to the topic at hand...I don't have this guy's budget, so I'll most likely have someone else craft a motor mount for 1/2 the cost of a cheap drill press.
I like to keep the material posessions to a minimum if possible and don't see myself needing a drill press before, say, a decent makita or something a little more useful to me ion a daily basis.

Where do you folks think I should start with the pinion and spur? Currently I have a 70 tooth(I think) RRP spur. I was thinking about going with maybe a 13 and a 17 tooth pinion for starters and after runing those, maybe have a better idea of what's needed if neither of them will work out.

[J3110]

Slight change of plans.
Since the EVX-2 took a dump the day my starluck combo arrived, I just decided to slap it into the 3905 to see how she runs.
Think I'll try and sell off all the stuff I don't use anymore and maybe invest in a buildup using decent components while I thrash on the 3905.
First run with the 7xl, I tried the stock settings, but had the punch down at 10%.
I could tell the driveline was crying for mercy(or at least it sounded like it).
Melted the glue in the 7-cell 4200mAh nimh packs I'm using at the moment.

So, I'm thinking I should just invest in a solid driveline, get a nice chassis and I should have the beginnings of a(hopefully) bulletproof brushless setup.

I'd like to have one of those crazy things that just dances on it's hind wheels when the throttle's pegged.

Currently, this setup is almost there.
Fast as I want it to be with aggressive settings and just faster than stock on mildest settings, yet easy on the gear. Only difference I'm after is I'll have to build something to withstand the constant abuse that is coming.

[J3110]

Check it out, yo!
A recycled t-maxx, pair of twinforce battery trays, few screws and plastic bits, 7XL and MM ESC. Should be fun.



It's been raining so I haven't had a chance to really open it up, but so far, it seems to be working.
Still needs a body and a couple new servo harnesses to get power to the fan and I forgot to disable reverse on the ESC, but other than that... :)

[Modding_out]

sweet! I did the same thing once. just like you have it there, but I disabled reverse on the esc and ran a ''y'' connector to the brake servo, this gives you the standard throttle/braking procedure with out having to hit the 3 channel. link>http://www3.towerhobbies.com/cgi-bin...?&I=LXPWA6&P=0

How do you like the 7xl 540c? there a hard to get/not very popular motor. But I like mine, every one opts for the cheaper 7xl 540.

[_paralyzed_]

nice. my t-maxxes may have to be converted. and thanks for the update, a year later!