HPI Nitro MT brushless conversion, where do I start?
 

I got an old HPI nitro RS4 MT (http://www.hpiracing.com/kits/nitromt/nitromt-m.htm) and im sick of keeping up with intro maintenance and wanted to convert it to brushless electric, where do I start? I've tried searching on google without any helpful infos, there some vids showing its been done but not much discussion about how to actually doing it. I'm opened to all suggestions, links, parts, etc.

Well, all you really need is a motor mount and battery tray. The motor mount will be the most difficult part since the nitro MT is so old. TBH I haven't seen where you could get a mount from, but you may be able to get away with a piece of aluminum angle.

thats exactly why i wanted to make it brushless instead of selling it, its so old that I dont think I can get more than a $100 for it on eBay, so I would rather keep it. I was thinking of the piece of aluminum angle too but where can you find such thing? I can do some mod to it but I need something to start with. Are the Tekno motor mounts any good?

The Tekno motor mount will work. You'll just need to drill 4 additional holes in the chassis, but it should work great for you. For aluminum angle, you can also use a Revo motor mount, and just drill the holes to mount that as well. Just something to think about... :yes:

where can I get the revo motor mount you're talking about? if its cheaper than Tekno, i'll go for that instead. Also with Tekno i really have to think about which motor I will be using as it offers 3 different sizes. I still dont know which motor I should use, what Kv? motor size? I got a spare Mamba Max esc that I will be using.

Here is the Revo motor mount:
http://www.rc-monster.com/proddetail...d=RCMrevomount

well I guess Tekno is a better choice for pice :)

but before I get it, what kind of motor would you suggest? I would imagine something of higher Kv? since I can't run too many batteries due to the weight and balance, may be 3s lipos?

this is what i want to get: http://www.impaktrc.com/product_info...d477cc85b119a2

also how can I find out which pinion I need and im guessing that with a nitro to electric conversion there will be no reverse?

it sounds like your on a budget so go for a 9L motor, 3s lipo, use your mm, and get a ccbec. gear it for about 35 to start with and go from there.

btw mike can make you a mount, if you send him one of your center diff mounts, as for a battery tray you coul use one off an emaxx, use an rcm tray, or make your own.

Use BrianG's speed calculator to figure out pinion. You will have reverse, unless you have a two speed on it.

ok thanks guy, looks like I have some ideas on how to start this thing. but BrianG speed calc doesn't have HPI intro MT and haven't a clue what settings (transmitter ratio, pinion pitch, etc.) to use, how can I find out? This is a one speed so I guess I will have reverse, cool. But what about that mech brake? remove it?

You just need to get your gear rations and enter them into the calculator under the correct positions. IE: transmission, spur, pinion, differential, etc.

The diff ratio should be 38/13 (2.923), and since there is no transmission that ratio is just 1, then enter spur size, and throw in a random pinion size, like 18. Press calculate, and adjust the pinion size to match the desired speed.

well that was the problem, I don't know those infos. im kinda new to this hobby too so i haven't a clue how to calc these things.

Edited: thanks MetalMan, you're a life saver

Not anymore, I quit lifeguarding about two years ago :lol:.

Just finished my Super RS4 convert
 

And the hardest thing was the mount. i made mines out of a piece of aluminum angle. I did a lot of parts out of dremelled aluminum. Getting a gear to mesh right with the stock gears was the next challenge. Mike's Mod1 pinion solved that one.

Yeah the pitch of the pinion is my next concern, i dont know which one would mesh up with the stock gear, but I have a few 32, 48 pitch to try out first.

Where do you get the piece angle aluminum at? Im pretty good with the dremel myself, I could probably make one

Lowe and Home Depot both carry aluminum angle. You could also order it online from www.mcmaster.com

I know the MT2 uses mod1 gears, I think the MT is the same.

cool, i got 13t mod1 I could try it out, i've just check the manual they used 52t for spur and 12t for the pinion

Well it seems most places i have look only sell them in really long length I dont need, do you know anywhere that sell for shorter length?

the one I put, www.mcmaster.com

They are a wholesale industrial supply place. A billion dollar company and have a little bit of everything.

i hear this can bend with a sick torque motor, maybe weld a brace or use it as a template http://www.offshoreelectrics.com/products.php?cat=43 .. I received a Tekno mount today, the ones for the losi 8T conversion, nice solid mount if you dont need to adjust it lol

wow thats beat the price of everything else i've been looking at and look like it could work, im not gonna use any powerful motor, the truck is pretty light weight. thanks Jay

Well after a whole day of searching for parts, nothing good come up and offshore is off on vacation so I said screw the retails and their products and decided to make one myself. I spent almost 3 hours to cut out a piece of alumium from a sheet that i had back when i was building a custom xbox case, then try bending it to angle with some steel bars with my dad's help, this is a toughtest part!!! Here is what I got to so far screwed to the chassis, now I have to figure out how to mount the motor and make it adjustable while getting a perfect mesh with the spur. It's not done yet, im just trying to see how it fits in and I will cut and make it smaller later, may be intergrate in a Feigao clamp as well. Let me know what you guys think and again suggestions/comments are welcome!

http://img.auctiva.com/imgdata/1/5/2...61091356_o.jpg

Here's what I did on my MT2

http://www.rc-monster.com/forum/atta...4&d=1167618322

Great job! very neat, I love it! did you make the mount? if so, how? how many cells are you running? which CC motor? gearing? speed? run time? does that CC motor run hot? how do you mount the servo to the bottom? mine is mounted to top chassis part and I dont like it, i want to get rid of the whole black thing you can see there on the other half on the chassis. Also, where do you get that carbon upper brace or whatever? is there one for MT1? where can I get a battery box like that? can I see the other side of the truck? Thanks for your help

Yes I made the mount, bent it up out of a flat piece of aluminum. Running 3s lipo. Tried the 5700, but it ran too hot, switched to the 4600 and it worked out better. I ran 12/52 gearing, about 45mph with the 4600 and about 55mph with the 5700. The servo is actually mounted to the upper deck, it is an hpi upgrade for the MT2 (may fit the MT). I will see if I can find some more pics tommorow. I used industrial wire duct for the battery holder, with a gorilla strap. PM me and I can send some of the stuff for the battery holder.

thanks for the info, also sent you a PM :)