It was funny watching your son jumping out of the way!

The CRT looks good. I'll bet it runs plenty fast when on a track.

So brian are you saying you have a screw loose ?:eek: .

Procharged: Like I said, he knows how I drive. :) He's probably still a little gun shy from when I literally knocked him off his feet when I was tooling around with the Hyper 8. That'll teach him for standing... well... pretty much anywhere. :) Yeah, it's plenty fast for the track I plan to race at. I figure ~30-35mph.

rchippie: Like you need me to tell you that? I thought it was obvious. :)

Brian your truck looks pretty fast. I have a 13t hardended pinion if your interested.

sweet truck, brian... looks so nimble and quick!

you shouldn't feel bad about your son jumping out of the way - you're sharpening his reflexes! :026:

rchippie: I might just take you up on that. I want to see how it runs on a track again where the pinion isn't loose first to see if the motor/ESC still gets hot.

Clod: LOL, I'll tell him that- I'm sure he'll appreciate it. :) Besides, It's not like I was anywhere close and when he did jump, it was a tad delayed so he needs his reflexes sharpened. :)

Cool video. Nice drive way for drifting. :027: Have fun with it!!

I thought it was pretty funny how your kid jumped right after the car passed him, lol. You've got to keep him working on those reflexes. :005:

Yeah, but those rocks hurt! One of the kids was at the other end of the driveway and got hit by a small rock from the Hyper 8. I need to sweep it clean of all rocks I guess, but then turns into a mudpit in the spring. Yuk.

Looks awesome Brian. Mine arrived today. I'm going to shoot Mike an E-Mail to order me my motor right after this post. I also made my own thread. Preliminary measurements show that the motor will fit with the stock brakes (wohoo!).

I'm already loving this little thing. I just need to get some stuff sold to get some funds for this thing. (My 18T, HV4.5 motor, and some other stuff).

I think you'll be happy with it! I can't drive worth a crap and I think it's a blast! :)

:005: I can't drive either but this truck makes up for a lot of that! It's so forgiving. I was able to get some video at my track that I just uploaded. I'll post a link as soon as Youtube processes it. Then you can all see how poorly I drive:D

Good News For Me
 

I just bought a CRT.5 it should be here thursday. I'm going to run it nitro i will be using a TRX 2.5. My friend orderd two he owns a hobby shop, so i got it at a real good price. I also ordered the ofna starter box for mini's .

Just ordered mine too. Mine will probably take a little longer then your to get running though because I will be converting it to brushless.

Boy, it seems like these are going to be popular little trucks! They just came out and there are already three conversions on this forum alone! If we keep this up, Mike will have to have two Monster Bashes; one ofr just CRT.5's, and another for everything else. :)

I ran my CRT around the house a bit more and am not very happy with the ESC and motor temps.

What's weird is that it is geared lower, is lighter, and the tires are smaller than the Jato, but the Jato stays cool despite the fact the Jato goes MUCH faster. CRT Mesh is just right - not too loose and not too tight. Everything spins smooth as silk so it's not the drivetrain. I want to keep this thing in the mid 30's speed-wise, so more voltage is out. I'm already using the MM 4600 motor.

I'm thinking that the motor isn't being loaded enough because the truck is too light and geared low. Things heat up just like if I were to run with the truck off the ground (unloaded). Everything I can think of to increase the motor load makes it run faster. Setting the radio EPA would solve the speed issue, but not the underlying problem.

So, was thinking of trying a Feigao 380c/9 (kv=4386). This would make the motor loaded perfectly I think. Any thoughts?

This is interesting. I haven't had any issues with my 4600 running 2S with 12t/46t. I'm going to kick it up a notch and put in a 13t pinion.

What temps are you getting? I'm right around 160*F on the motor and around 150*F on the ESC, which is WAYYY too hot for my liking. Some people think this is OK, but I don't. Batteries are at about 120*F.

I'm using a 16T pinion, but that only creates a FDR of 9.5, while the Jato (running larger tires) is running a FDR of 9.638. The Jato, which is bigger and heavier, runs forever without getting anywhere near as warm as what the CRT.5 is getting.

The temps lead me to think it's overgeared, but then I compare the Jato and I just don't see it. The only other thing I could think of is that it's not loaded enough...

Could not being loaded enough make that much difference? I kind of doubt it but I'm certainly open for some education on the matter.

lol, I don't know. Oddly enough, this is the hottest conversion I have and the lightest. Like I said, the temperature rise feels just like if I were to put my truck on a stand and run it near WOT.

Well adding load seams easy enough. Give it taller gearing and see what it does. I'm betting it will run even hotter.

Well, I don't have anything higher than 16T. Nor do I have anything smaller. Plus, I'm currently running the hardened steel pinion so my options are limited.

How you manage to run a MM motor on your Jato without melting it is a mystery to me. Too me this looks like another epidemic classic case of running too high kv motor on a 10th scale truck.

Well, the Jato is 1/10th scale, which is what the MM is designed for, and everything runs cool. Don't know why, but it does. I'm lucky if the temps get to 140*F on a really hot day after two battery packs (~90 minutes) and doing constant high speed runs or track use.

Since the CRT.5 is 1/12 scale, it should be fine, especially since I chose the lowest KV motor in the MM series. Plus, I'm running only 2s.

I can see having issues trying to run the 7700 motor on 3s geared high, but I'm not. Gearing is a little high, but not too bad IMO.

The Jato probably runs cooler because it's 2wd vers 4wd with the crt.5 your running the power through 2 more diff's and 2 more tires. :)

FYI my crt.5 with the 5700kv Mamba and 3s lipo runs around 150deg with a 13/46 Kyosho gear.

Brian, it wouldn't surprise me when your temps come down once you get the chance to try a higher gearing.

BTW, this 160/150 temps, how long does it take to get there?

Yeah, higher gearing would load the motor more, but then it's too fast. That's why I was thinking about going with a smaller motor, like the Feigao 380c/9. Then, I could get the same speed with the proper gearing. This is for a small track, I wanna keep it under 40.

I haven't checked at various times throughout the run, just at the end of the 5Ah pack, which takes about 30 minutes, maybe a little more. So, the temps could rise quick and stay there, or they could gradually increase, I don't know.

Instead of getting another motor, I would simply set the throttle EPA down some...

I thought of that, but that doesn't change the load. I like the speed I'm at now, the temps just get too high. I figured a faster motor would be loaded correctly and then I could use the EPA to dial down the speed.

150F after 30 minutes doesn't seem terribly hot to me. Not cool, mind you, but not too hot, either. I have 20 tooth hardened gears if you want to try getting more speed and dialing back the epa. Typically, if the controller temps at 150 and you feel this is hot, less load would be appropriate. The motor could go either way, though(too much or too little load can cause heat in the cheaper motors). You could always use the dreaded $10 fix as well("f" word), though I know this is against your religion or something. :)

I spent a few hours last night working on a delrin spur for this little gem. I got the file worked out perfectly and proceeded to cut 5 spurs(40 tooth delrin). I was using a molded spur gear and machining both sides to replace the stock spur directly. After the first operation, all the spurs seemed fine. The second operation, however, revealed the flaw of a molded spur gear....air pockets from the molding process. Not a single usable spur after hours of work(though the file and cutting program are perfect, the air bubbles are all in the middle-right where I need the strength)). I will spend the early part of this week sourcing a suitable spur(hopefully) so I can complete the conversion. I did modify a kyosho spur to work as well. It will require an 8x14 bearing(which I happen to have) - not a big deal, as I can make this into the motor mount, but I prefer a custom spur rather than modifying the Kyosho and requiring a special bearing). I ended up with around 6.5mm toothwidth vs 5mm on the Kyosho - the Kyosho spurs also rubbed the diff mount a little. The Kyosho gears themselves are pretty cheap, though.

Any thoughts on plan B(modifying Kyosho spur and including the bearing into the motor mount)?

OMG, you used the F word! :036: lol. No, no fans for me. I hate them (as you seem to know).

Well, it's hot compared to everything else I've run, which is 140*F at the absolute worst, and I hate electronics getting too hot. It's amazing how much the specs of the FETs are derated when the temps get that high. A 100A ESC turns into a 40A ESC.

I've been running like this simply because I'm waiting for your drop-in CRT.5 mount (hint, hint ;)). Hopefully whatever you make will allow me to still use the battery tray I spent hours making! :) I still think it would be relatively easy for someone with a mill to make a diff adaptor "cap" (in place of the stock spur) that bolts to a hollowed out Kyosho spur. This spur would slide over the diff cup. But I'll leave the designing to you.

Not that I'm trying to rush you, but if the custom mount looks like it may be a few weeks away, let me know via PM and I'll probably look at using the 20T pinion.

lol, you posted again while I was typing.

Anyway, that sucks that you spent so much time for nothing. I know how it feels. Imagine using a hand dremel to do that! Any little bit off and you have to start over. Arrgg.

I think that any solution you come up with will be most popular if there doesn't need to be any new chassis holes drilled for the diff mount. I can't see any way of using the Kyosho as-is without moving one of the diff mounts due to the rubbing - the geometry of the stock vs Kyosho are just too different IMO. Of course, if a combo diff mount/motor mount is made, there are more options since you can use pretty much any existing chassis holes and you don't necessarily need to use the standard diff mount holes.

I am right there with you on the heat, Brian(heat is the enemy), though I have no aversion to any of the "f" words really. :)

Adapting the Kyosho spur is pretty easy - a few minutes and a steady hand on the lathe is all it takes. It is tedious, though(and if you cut too much, the gear is junk - this is why I prefer cnc - the machine doesn't get distracted and make mistakes). I guess a brass spacer could allow use of the stock bearing as well(similar concept to the bore reducer). Maybe I am making it too difficult here. I wanted a custom spur(hopefully a few teeth options as well) for the best fit, but the Kyosho spurs may be the easiest and cheapest way to go.

I agree - I like to make parts that bolt in without requiring chassis mods(I take drilling and stuff for granted, as I do it every day and have the equipment - I try to make stuff for the folks that don't have these assets). Most people have an aversion to drilling holes it seems. :)
I think I could make the kyosho fit after modifying it - I could simply change the bearing depth and move the lower mount drill/tap location to offset the rubbing. Still, I am a sucker for a custom part. :)

Hey Mike I'm going to check into the custom gear thing... I'll call you if it sounds promising. If you are willing to consider outsourcing for it anyway... I know some guys who might be worth talking to. They used to machine a lot of plastic gears years ago....

I will be happy with what ever you come up with. I just ordered the little sucker and should have the truggy later this week. anyways let us know what you come up with.

Yeah, I was looking at using the Kyoshos because they were available and fairly cheap. I do know that even the 44T spur will rub the chassis, so the whole mount may have to be raised - unless a whole different spur is used (Revo?).

It's funny that such a simply little truggy could be so difficult to find a usable solution to use a plastic spur...

Dustin - I am always searching for new sources. I don't mind machining them, but if I don't have to then that makes it even sweeter.
Brian - The gear I modified was a 44 tooth kyosho - I did notice it was dangerously close to rubbing, but I didn't actually run it to verify(it rubbed the mount anyways, so I scrapped it and machined the molded gears I had here).
Tom - trust me, I will be sure to post when I have it done - I want to get mine going(could have it done, but I want to make something everyone can use) and this little unit seems to be quite popular so far(too new to tell long term, but a bolt on conversion should help). Mine may ultimately get another inch of wheelbase as well(custom chassis). :)

Well, at any rate, thanks for stopping by tonight Mike! Now get back to work! ;) J/K

LOL. I am on the forums pretty much every day, actually. I just don't log in most times - just browse the boards and see what's kickin'. I couldn't help myself hen I saw another Revo support mounted backwards, though. Besides, I wanted to mention the progress(or lack of) on this little conversion project.
:)
While I source the spur, I hope to finish the Kyosho buggy/truggy mounts and the losi 8T mounts this week(along withe a few custom/customer projects). :)