RC10 rebuild and some questions

[stealthboy2600]

Hello! New to the board so I appreciate the opportunity to post here. Looking forward to a lot of great discussion and getting involved.

This past weekend I tore down and rebuilt my gold pan RC10 from my childhood. I have a newer Hobbywing ESC, flysky receiver, basic NiMH batter, and put an older Fire Hawk brushed motor in it. It's setup with the stock 32pitch 54T spur and 14T pinion. So, it was great to tear it all down, clean it really well, built it back up... but then I went to run it and it seemed so... slow. Now, granted, I have a new RC10B6.4 that is screaming fast with a brushless setup, so I'm probably just experiencing skewed expectations and revisionist history, but I really don't remember it being so slow running it before.

Long preamble, but my question is, what can I look for in debugging first (if perhaps part of the setup just seem off to you), or what you would recommend for a brushed setup for my vintage RC10 if I'm looking for decent speed without using a brushless motor? Probably a huge question so I apologize in advance.

Here's a pretty picture of my rebuilt RC10 with the same shell I painted this way circa-1990.

[Frankentruck]

Welcome! Cool paint job!

What condition is the Firehawk motor in? Is the comm shiny copper or dark and burnt? Are the brushes worn and short? Do the brush springs have good tension?

For the ESC, are you certain that you have it wired to go forward correctly? If the ESC reverse direction is used to go forward, sometimes the ESC reverse is only partial power to the motor.

Does the radio have % reduction of CH2 signal put?

[stealthboy2600]

Hi, thanks for the followup. As far as I can tell the motor looks to be in excellent condition for its age. The brushes look great, the springs are excellent. No unusual burning or dark marks. And as far as I can tell the ESC is wired correctly because it definitely goes slower in reverse at full throttle reverse (just testing on the bench) but I'll look at this to verify. Good points!

Do you think my stock 54 /14 gear setup is fine? I know back in the day I played with odd ratios but I've completely forgotten about what I did. So on the rebuild I just went back to stock to be safe. But that could very well be part of it.

[juicedcoupe]

Did you verify that the transmission was smooth before assembling everything else? If the thrust bearing gets knocked out of place during assembly, it will bind the transmission.

[stealthboy2600]

Did you verify that the transmission was smooth before assembling everything else? If the thrust bearing gets knocked out of place during assembly, it will bind the transmission.

Yeah, the transmission was very smooth after I rebuilt it - Honestly I was quite impressed with myself, haha . It was so much better than before the rebuild. But that is absolutely something to check so I appreciate the question! All good points so far.

[juicedcoupe]

That gear ratio sounds a little tall for a 24°stock motor, especially for anything other than dirt or gravel.

A 12 or 13T pinion may be better suited.


I don't believe that the Firehawk was considered to be fast to begin with. More like a kit motor or stock replacement.

You mentioned a Hobbywing esc. 1060? They are known to go into a sorta "limp mode" when in high load conditions (like being over-geared and/or in tall grass). I've got capacitor packs on the battery side of some of mine to limit this. Just something to keep in mind.

[stealthboy2600]

That gear ratio sounds a little tall for a 24°stock motor, especially for anything other than dirt or gravel.

A 12 or 13T pinion may be better suited.

I don't believe that the Firehawk was considered to be fast to begin with. More like a kit motor or stock replacement.

I'll try a smaller pinion and go from there. Thank you for the suggestion - I honestly do not remember what even motivated me to get the Firehawk. It was a long time ago!

You mentioned a Hobbywing esc. 1060? They are known to go into a sorta "limp mode" when in high load conditions (like being over-geared and/or in tall grass). I've got capacitor packs on the battery side of some of mine to limit this. Just something to keep in mind.

Now this is interesting - because a little while ago (before the rebuild) I tried a newer Reedy Radon motor and it seems like it did what "going into limp mode" describes. It ran decently for maybe 30 seconds, then the max throttle went way down (by half?). Sounds like that was the issue. So perhaps I'll try the capacitor addition and put that Radon motor back in and see what happens.

I really appreciate the insight! I apologize for the stupid questions - I'm just now getting back into things and I'm having to learn a lot all over again. Just for a bit of backstory, my son recently got into R/C cars and we built a Tamiya BBX kit together. So I've caught the bug again.

[JosephS]

That gear ratio sounds a little tall for a 24°stock motor, especially for anything other than dirt or gravel.

A 12 or 13T pinion may be better suited.

I don't believe that the Firehawk was considered to be fast to begin with. More like a kit motor or stock replacement.

I'll try a smaller pinion and go from there. Thank you for the suggestion - I honestly do not remember what even motivated me to get the Firehawk. It was a long time ago!

You mentioned a Hobbywing esc. 1060? They are known to go into a sorta "limp mode" when in high load conditions (like being over-geared and/or in tall grass). I've got capacitor packs on the battery side of some of mine to limit this. Just something to keep in mind.

Now this is interesting - because a little while ago (before the rebuild) I tried a newer Reedy Radon motor and it seems like it did what "going into limp mode" describes. It ran decently for maybe 30 seconds, then the max throttle went way down (by half?). Sounds like that was the issue. So perhaps I'll try the capacitor addition and put that Radon motor back in and see what happens.

I really appreciate the insight! I apologize for the stupid questions - I'm just now getting back into things and I'm having to learn a lot all over again. Just for a bit of backstory, my son recently got into R/C cars and we built a Tamiya BBX kit together. So I've caught the bug again.

If you are using a NIMH pack, have you set up the 1060 to be in Nimh mode? Is the battery new as well? The voltage falloff is higher for NiMh than Lipo and and can cause odd behavior you are noting.

[stealthboy2600]

If you are using a NIMH pack, have you set up the 1060 to be in Nimh mode? Is the battery new as well? The voltage falloff is higher for NiMh than Lipo and and can cause odd behavior you are noting.

Yep - configured for NiMH mode, and it is a new battery.

[JosephS]

If you are using a NIMH pack, have you set up the 1060 to be in Nimh mode? Is the battery new as well? The voltage falloff is higher for NiMh than Lipo and and can cause odd behavior you are noting.

Yep - configured for NiMH mode, and it is a new battery.

It sounds like you have another car that works. Is the calibration correct on the radio? Can you see if the speed stay the same with different calibrations/setups from a different car?

[stealthboy2600]

Thought I'd post an update! I decided to put in a newer Reedy Radon motor, which I had in briefly before but it kept slowing way down after 10-30 seconds of running. Thanks to this thread, that was identified as an issue with the ESC going into limp mode. I installed the capacitor upgrade, put the motor back in, and with a fresh battery it worked perfectly! I still have the original 14/54 gearing but I have a 12T pinion coming in this week.

So, it's back to what I would call "decent" performance, the ESC does not go into limp mode, and I'm a happy vintage RC10 owner once again. I think I'm going to stick with the brushed setup to keep it at least vintage in spirit.

I really appreciate all the help here. Such a great community!

[Frankentruck]

Which Radon motor are you using? Is it a Radon or a Radon 2? If a Radon 2, is it the 15, 17, or 19 turn motor?

[stealthboy2600]

Which Radon motor are you using? Is it a Radon or a Radon 2? If a Radon 2, is it the 15, 17, or 19 turn motor?

It's a 17 turn Radon (doesn't specifically say "Radon 2", just Radon).

[juicedcoupe]

Which Radon motor are you using? Is it a Radon or a Radon 2? If a Radon 2, is it the 15, 17, or 19 turn motor?

It's a 17 turn Radon (doesn't specifically say "Radon 2", just Radon).

The red one. It was the kit motor for brushed SC10's, maybe some others.

The SC guys weren't crazy about them. But I suspect that improper maintenance, overgearing, and inexperience probably account for most of it.

I have a couple of them. While it isn't anything special (a far cry from a true 17T mod), I don't think that it's particularly bad in any way.