grimlock 97 Posted January 25, 2020 Hi! I am working on my MF-01X Jimny SJ30 but found out that the rear part of the body will be very, very close to the stock 540 engine. I think when the engine gets hot, that would not be good for the lexan causing it to warp or something similar bad. So my idea was to fit a smaller diameter engine. i.e. the 380. Which would also allow more runtime and make the car slower like the 1:1 ;-). Does anyone has put a 380 in the MF-01 X chassis? Any advise appreciated. Best Martin 3 Share this post Link to post Share on other sites
Juggular 4964 Posted January 25, 2020 I'd say any experiment is fun. You could use a heat sink to cool the motor. But the gear ratio of 9.5:1 is quite low. I don't think the motor would get hot enough to need a heat sink. (but I like to use heat sink anyway) Or you can use the End Point Adjustment on your transmitter to limit the throttle down to 70% or so. It would run slower, and it wouldn't get hot. But if you want, you can experiment with a 380 motor. The biggest difference might be from its weight. 540 motor weighs about 190 gram. 380 motor weighs 71 gram. That's as much as 21 quarter coins (or sixteen 1 Euro coins). The weight change can turn it into a new chassis. The tail end would get much lighter. Theoretically, MF-01X should behave more like a mid engine car. If you want it to perform better, you can get "380 Sport Tuned" motor. Less than half the weight, faster speed, but less torque. Below video was for the FDR (Final Drive Ratio) of 6.6, which is why it accelerated slower. But for FDR of 9.5 (MF-01X), it might be a good fit. 1 Share this post Link to post Share on other sites
Blissard 359 Posted January 25, 2020 I was thinking about the same thing for my SJ30, slower, lighter and more run time. But from what I see 380 motors won't fit 540 mounts because of screw holes. Or do they ? Also does the electronics we use on 540 motors work with 380 motors ? 1 Share this post Link to post Share on other sites
J@mes 2326 Posted January 25, 2020 1 hour ago, Blissard said: Also does the electronics we use on 540 motors work with 380 motors ? I got a sport tuned 380 running on a TBLE-02S in my mini lunch box no issues 1 1 Share this post Link to post Share on other sites
WillyChang 1814 Posted January 26, 2020 2 hours ago, Blissard said: I was thinking about the same thing for my SJ30, slower, lighter and more run time. But from what I see 380 motors won't fit 540 mounts because of screw holes. Or do they ? Nope. Screw hole location different. Need some form of adaptor plate. Motor pinion shaft smaller. Need some form of "tube" spacer for 540 pinion or different pinion. 2 hours ago, Blissard said: Also does the electronics we use on 540 motors work with 380 motors ? Electrons are agnostic, they don't discriminate. The vital specs are voltage and (max) current. Brushed motors aren't too fussy, 380 runs fine on same volts as 540. Smaller motor smaller current so ESC for 540 will enjoy easier job. 1 Share this post Link to post Share on other sites
WillyChang 1814 Posted January 26, 2020 4 hours ago, grimlock said: I think when the engine gets hot, that would not be good for the lexan causing it to warp or something similar bad. Line the body to protect with aluminium foil tape. Make a heat shield with sheet metal... eg cut up a coke can Lexan gotta be heated to at least 150degC before anything goes bad, wouldn't worry too much. Even with nitro cars & their hot exhausts... don't see much damage on the lexan from touching hot engine parts, it'll usually be lost paint rather than melted. If 540 ever got to 150degC on the OUTSIDE of the can... I'd be more worried about the ABS chassis melting. The motor screws will probably cut thru the chassis Share this post Link to post Share on other sites
Blissard 359 Posted January 26, 2020 8 hours ago, WillyChang said: Nope. Screw hole location different. Need some form of adaptor plate. Motor pinion shaft smaller. Need some form of "tube" spacer for 540 pinion or different pinion. Electrons are agnostic, they don't discriminate. The vital specs are voltage and (max) current. Brushed motors aren't too fussy, 380 runs fine on same volts as 540. Smaller motor smaller current so ESC for 540 will enjoy easier job. Thanks for the information. I should have known that about motor shaft. Share this post Link to post Share on other sites
WillyChang 1814 Posted January 26, 2020 1 hour ago, Blissard said: Thanks for the information. I should have known that about motor shaft. If needs be... recently noticed my Mini Lunchbox kit supplies that very adaptor tube to use 540 pinion on 380 motor. Don't need to DIY anymore! 1 Share this post Link to post Share on other sites
WillyChang 1814 Posted January 26, 2020 And if you need 380-to-540 adaptor plate, maybe the Grasshopper kit can provide. (or is it Hornet kit that will leave that plate free, since Grasshopper uses it. But then you'll have to find a 380, not just steal the Grasshopper's motor.) 1 Share this post Link to post Share on other sites
Blissard 359 Posted January 26, 2020 2 hours ago, WillyChang said: If needs be... recently noticed my Mini Lunchbox kit supplies that very adaptor tube to use 540 pinion on 380 motor. Don't need to DIY anymore! Awesome! Just found it in the manual. I haven't looked into mini Lunchbox before, it looks like a great chassis. Share this post Link to post Share on other sites
grimlock 97 Posted January 27, 2020 Thanks for all these ideas. I may try the easiest solution first and use some heat shield. Hope it works out. Share this post Link to post Share on other sites
nowinaminute 2815 Posted January 27, 2020 You could try a 390 motor, same dimensions except it's a bit longer and more powerful. It is to a 380 what a 550 is to a 540.... 2 Share this post Link to post Share on other sites