Custom Carbon Fiber Brushless RC8T Pics - Page 5 - RC-Monster Forums

Ryu James · 12.24.2008, 01:32 PM

thanks rootar,
i have already moved the chassis brace after talking with Mike. and i mounted the esc where it is for better l/r balance but i dont like it there so i am going to move it behind the battery today. i am also putting im mech. brakes today. i think it will be sweet when done.

12.24.2008, 01:36 PM

take lots of build pics for this noob.

Ryu James · 12.24.2008, 02:40 PM

Quote:

Originally Posted by BL Dreamer

take lots of build pics for this noob.

already was planning on it. i will post them all when finished.

Ryu James · 12.26.2008, 06:51 PM

here is the build pics of version 4 as promised. still needs some adjusment though. because the center diff sits so high off the chassis with the RCM conversion i had to use 3 shims on the servo stands and 1/8" of spacers on the servo arm and the servo still doesnt sit high enough. so i am going to somehow try to make the setup work without the huge center diff shim.

i also had to use a Tekno long shank pinion after making the spacer so that the motor can didnt rub the brakes. anyway, the pics tell the story for the most part.

i also move the esc behind the battery. looks much cleaner.

2 pices of 3mm carbon glued together for a 6mm piece. just enough to clear the brakes now. one side had to be ground down to clear the brakes. 2 screws hold the piece against the motor and the other two screws hold themotor to the mount.

Ryu James · 12.26.2008, 06:55 PM

a couple more pics. the things seems to drive great now. havent been able to test on track yet but will soon. love the mech brakes finally.

pic of the shims and nut used for spacer on servo arm

MetalMan · 12.29.2008, 01:17 PM

Aluminum may be a better material for the brake spacer because it is thermally conductive - as is the motor mount. CF won't transfer any heat, so your motor might run a bit warmer than with an aluminum brake spacer.

Here is something else to consider: you could use a smaller servo for the rear brake only to save weight, and then mix in motor brakes since the motor brake tends to get transferred to the front anyways (this is what causes these conversions to push with motor brakes only). With this setup you can tune the braking from your radio without messing with any linkages. It's just a thought, and this is the setup I am using on my 1/8 buggy.

Ryu James · 12.29.2008, 01:43 PM

so this weekend i had it on the track finally. it did seem to run hotter than normal. after 20 minutes of hard driving my motor temp was 144*, esc was 135*. this is on an indoor track so ambient temp was roughly 70*. this is alittle warmer than i like to see so i may try the alum suggestion but i dont have any thick enough right now.

i have made some adjustments since the last pics. i got rid of the center diff shim so that the brake servo lines up without all the shims and also this really lowered my CG. i am able to run 13/46 gearing now for less rotational weight.

the thing drove amazing at the track. after a few suspension tweaks it was perfect and absolutely nobody was even keeping up. there was a lot of interest in it. hope this spurs others to build their own 1/8 conversion since it is in its infancy here.

anyway, i am pretty pleased with it right now and dont plan to make any changes to this current setup for a little while. i still want to build a carbon chassis that will work so i will be building a milled 3mm carbon chassis with kickup. i think this will provide the flex that is needed. i also now have the tekno chassis for the RC8T and it looks very nice so i plan to try that soon also, maybe with a complete separate build though.

Spencer! · 02:05 PM

im not sure if anyone has mentioned this before about the kickup on the front section of the chassis but carbonfiber can be heated and bent the trick is rapidly cooling it off to maintain strength and shape. Just remember to much heat can hurt you where as not enough heat will not ruin anything.

I also made a carbon fiber chassis (4mm) except mine was for my 8ight buggy...
here is a picture from way back when it was still in building/planning stages and investment in a neu motor

Ryu James · 12.29.2008, 04:19 PM

so i tried the idea of heating up the carbon to bend it and it worked but it also ruined the integrity of the carbon as i suspected. its still pretty tough but i dont think it will hold up off a big jump. its actually really strong if i push on the nose upward but if i push against it downward i can hear it cracking. i could probably break it with my hands. however, most of the force put on the kickup is in an upward motion so it might hold. this chassis has become just a test/throw away chassis so i am not too worried about it. i am going to order some 3 and 4mm pieces to find the best mix of strength and flex. this 5mm piece is just too stiff.

you can see in the pics that the layers of carbon have slightly separated and the outer layer has bubbled away from the others. also, this produced a large wrinkle on the surface that i tried to dremel down but it still may affect how the front diff case mounts up. might not sit real flush.

i think with some practice this could be done without ruining the piece at all. i didnt think to try it a few times on some other scraps before doing it on the chassis. oh well. thanks for the tip.

pb4ugo · 12.29.2008, 06:15 PM

Quote:

Originally Posted by Spencer!

im not sure if anyone has mentioned this before about the kickup on the front section of the chassis but carbonfiber can be heated and bent the trick is rapidly cooling it off to maintain strength and shape. Just remember to much heat can hurt you where as not enough heat will not ruin anything.

I also made a carbon fiber chassis (4mm) except mine was for my 8ight buggy...
here is a picture from way back when it was still in building/planning stages and investment in a neu motor

The epoxies used in CF are not thermoformable. The only way to have a structurally sound bend in it is to mold it there.

pb4ugo · 12.29.2008, 11:40 PM

Quote:

Originally Posted by Ryu James

this is completely true and apparent after trying this out. i do have a source now that is going to make a custom matched tool so that i can get some carbon sheets with the kickup angle molded in. these will be absolutely awesome and should be available for retail purchase. i will know more soon.

Didn't you buy this piece from Dave Inkel (D.A. Graphite)? He used to do chassis back in the day with the kick up molded in. I spoke with him about doing it for me a couple years ago and he said he could if I sent him the form. I never did because I decided it would be cheaper and more fun to do it myself.

slimthelineman · 01.01.2009, 06:29 PM

i know its for a losi but check this out http://www.matrixconceptsinc.com/

Ryu James · 01.02.2009, 06:48 PM

yeah, i have seen those. i dont like how they are a 3 piece design though. i think that would make it weaker. i have never raced one but the guys at Tekno race against drivers that use the Matrix chassis and say they have held up great.

i have another carbon plate coming next week that i will be using to build a chassis for my RC8T and my Losi 8t. these will have the kickup molded into the plate and be 3.2mm so that there will be flex. i am hoping this will be the right combination to be a great setup. last time the 5mm plate was just too stiff. i have test the 3mm carbon and it flexes nearly the same as an alum 3-4mm chassis. cant wait to get these built. i will post the results.

Chadworkz · 02.22.2010, 09:31 AM

I know this is a little bit old, but I just wanted to mention that the method Matrix uses to build their CF kick-up chassis is just as strong as a regular sheet of CF. They use a bonding agent that is stronger than the CF itself, and the aluminum inserts are just plain awesome...they keep the droop screws from digging into the CF causing rough holes, and help in other areas where parts will me moved around a lot, such as the motor-mount etc..

Anyway, Ryu, awesome build and work on your CF chassis, and everything else you did...excellent job! I work with CF quite often, and know its pitfalls and benefits, and even know, or have discovered, quite a few tips and tricks to use when working with it.

I am actually getting ready to start building my own custom brushless CF E-Maxx Truggy (LCG) Chassis (with kick-up) and custom brushless CF Revo Truggy (LCG) Chassis (with front kick-up & rear kick-down), so keep an eye out for those threads.

Ryu James · 02.22.2010, 08:51 PM

Quote:

Originally Posted by Chadworkz

I know this is a little bit old, but I just wanted to mention that the method Matrix uses to build their CF kick-up chassis is just as strong as a regular sheet of CF. They use a bonding agent that is stronger than the CF itself, and the aluminum inserts are just plain awesome...they keep the droop screws from digging into the CF causing rough holes, and help in other areas where parts will me moved around a lot, such as the motor-mount etc..

Anyway, Ryu, awesome build and work on your CF chassis, and everything else you did...excellent job! I work with CF quite often, and know its pitfalls and benefits, and even know, or have discovered, quite a few tips and tricks to use when working with it.

I am actually getting ready to start building my own custom brushless CF E-Maxx Truggy (LCG) Chassis (with kick-up) and custom brushless CF Revo Truggy (LCG) Chassis (with front kick-up & rear kick-down), so keep an eye out for those threads.

Hey Chad,
thanks for the post. i had no idea that much work went into the matrix chassis'. they sound like they are very solid and i have only heard good things about them. i havent worked with carbon for a while now but only because i havent been doing any builds. i have held off RC spending for $ reasons for the time being but i have my sights set on my next project and i will be doing lots of carbon work on it. i plan to convert the new 1/5 MCD RaceRunner V4 that just came out. i am waiting for the ultimate version to come out though which is due this fall. the chassis on the MCD is flat and caster is achieved through the gearbox parts instead of bending the chassis. so it will be a perfect candidate for a carbon chassis that wont require any bending. for those of you who havent seen the V4 yet you got to check it out. they have stretched it to the same length as the Baja 5B now but of course it has 4wd. should be sick!
anyway, Chad, if you are willing to share i would love to hear what things you do to work with carbon. have you found a good way to CNC it? if you dont want to post PM me at least. i have done a lot of stuff with carbon but have yet to perfect the process. the last time i had it on the CNC i was still running into issues of fraying etc. any tips you can give would be much appreciated. thanks.