Gruber
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M.L. Toys
KidsWheels
Gruber
HobbyMasters
M.L. Toys
KidsWheels
HobbyMasters M.L. Toys
Gruber
KidsWheels
Need new motors? Grind a gearbox? Adding teeth to a pinion?
User avatar
By Nateo
#148792
I am new on here and have spent the last few days reading through alot of great posts on hear. I am not very forum savy though. I am having a hard time compiling all the data into one place for what I am looking for. I know these questions have been asked and answered, so if I am out of line here let me know.
I have a dune racer I just acquired and am looking for a little more speed but keeping it somewhat simple and reliable. I have played around with batteries in another car so I am somewhat familiar with that aspect. I was contemplating putting 24v to the racer, with 775 motors and a steel pinion and first gear. The question I have is these nichibo 775 motors say they are 12vdc, can I put 24 to them, and is anyone doing it successfully?
User avatar
By Hammer-fm
#148794
The highest I've run any of mine is 22V and that's with a current limiter (40A max). So far so good but that particular vehicle hasn't had a ton of use. That being said, that same vehicle did previously burn out a Banebots 18v 775 motor (Mabuchi 8514) at 22V (after ~6 months of more-regular use). I think it's going to depend a bit on the load: The Banebots failed after it was driving for an extended period of time by two 4th-graders, so figure a 150lb load. With a single child it likely wouldn't have gotten hot enough to fail, at least on pavement.

At 24V the Nichibo is running 30k RPM. It probably won't last "years", but if the failure ends up just requiring a motor swap and doesn't break anything else, that may be fine. Buy a batch of 4 of them and if they're burning out way too quickly, you're only out $15. :D (oh, and if you do build that, let us know how it comes out).

(BTW, I'm assuming that when you say "Nichibo motors", you're talking about the 7013F I posted in the motors/gearbox section, not the older 9009F or other models. Someone was running a rig using 9009F motors at 24V with an ESC and said it lasted a few years, and that is 40,000 RPM, so there's a chance the 7013F will survive 24V ok...)
User avatar
By Nateo
#148798
Thank you hammer. Yes I was referring to the 7013, I have gotten alot of good info from your advice. My son is 5 so as of now the load shouldn't be much. I ordered 4 for 16$. I will definitely keep and update going. The biggest problem I have is i m not sure the boy can grasp the esc system yet, and I am trying to keep it simple for him. I have steel gears coming, but I don't know how long the gear boxes will last. Guess we shall see.
I had originally thought about better 550 motors and 18v, but I figured 775 with 18 or 24v would be more reliable and hopefully a little faster. Are the 550 motors at 18v faster, or will I get more rpms out of the 775 at 24v?
will the high low lever still work? Or will it just be in high all the time? Sorry for all the questions.
User avatar
By Hammer-fm
#148799
If you are just wiring batteries in series to get 24V, then the high-low switch will still function normally.

We've had a few "guest" drivers and they pick up the ESC pretty quickly (in fact, one of the guest drivers was very reluctant to drive their family's normal Corvette PW because it was "too fast", but was happy driving the faster Mustang because she figured out quickly how to control the speed). But ESC is a bit bigger rewire job.

The 7013F run pretty much exactly the same speed as the stock 550 motors, so at 24V they'll be twice as fast as what you have now -- assuming you're using the same # of teeth (you'll buy a 16T pinion for the Dune Racer so it fits the gearbox properly, but I don't know if they come with 15 or 16T from the factory).

You can buy faster 550 motors (such as the other Nichibo in the thread, or many of the RC car ones) but you won't get the higher thermal mass and heat dissipation capabilities that a 775 motor gives you. If you used the KC3- 23k RPM one from my thread at 18V it would be slightly faster than the 775 @ 24V, but would likely have a very very short life.
User avatar
By Nateo
#148800
Awesome. Thank you for the info. I am looking for some reliability as well so sounds like the 775s will be what I am looking for. So long as they last a little while. I am going to look into the esc, but not right away. I will update with more info when I get going on the project. I really appreciate the help. Thank you.

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