OVER REV on Holmes Puller Pro..

[MattySlimz1987]

So today I hooked up the Castle Link to change the throttle percentage down or the startup speed because after a short full throttle pull, I did a finger test through the rolled down window on the body I'm using and it was unusually warm. I did a full throttle run for about 20 yards out and 20 yards back. The motor is a PP 2700 standard and was ran on 3s. Esc is a Mamba x. When I originally installed this motor and controller it was with the prior firmware from Castle which I believe was version 1.82 and I set the power to 90% figuring that would be all I need and would be in the safe zone. Also set the start-up speed to Medium. When update 2.02 came out, I left everything the same and just changed to the new feature of race/rock mode. Mr. John Holmes' website states the PP"s max rpm is 50,000. Now tonight when I go to adjust the settings I decided to download and veiw the data log. Low and behold there it was, I saw that the motor rpm went all the way to 62,000!! Now I know these motors (especially 4 pole sensored) were designed for smooth technical crawling but also for rock racing, so I'm hoping no damage was done. The other sensorless motors I have in bashers get hot, but I'm not as much worried about them because they have blowers wrapped over most of them and are 2 pole sensorless. This one I'm more concerned about.

As you can see on the data graph, they were only about 3 short burst's and the motor wasn't very hot, I could keep my finger pressed hard on the can for a longtime without having to back away. Temperature in the area on this beautiful Easter afternoon was a mere 76 to 79 degrees. Everything seemed fine afterwards, smooth crawl, no weird noises, just hoping no damage was done to the stator or anything else in there. Set the level down to 60% now as thats all I need and so that this doesn't happen again!

*note: Temperature is the esc shown, temp for the motor is only logged while in "sensored only" mode. My setting is SmartSense mode. Graph indicates readings that are set at 1 per every 2 seconds.

Only info I could find was here::

Originally posted by John Rob Holmes from this thread. HH Puller Pro 3500kv standard owners? - RCCrawler
"The voltage recommendation doesn't max out the motors. 3500kv will take 4s, 2700 will take 5s, 2200kv 6s. But systems get finicky and easy to destroy without very detailed testing at those voltages. Possible, but not generally recommended."

Any other experience/suggestions on settings or info about if the motor is ok would be greatly appreciated. Also do you believe this information the log is giving me is accurate? The temp noted for the esc on start up says 24 degrees Fahrenheit... it was almost 80 degees out today.. has me questioning the accuracy of the data it collects..
Thanks!

 

[svt923]

Exceeding the recommended max RPMs in momentary spikes isn't normally going to damage the motor if heat is not an issue. The rotors on some motors will shatter under high RPM situations but I would suspect Holmes is being rather conservative with their 50K max recommendation and it would take much more than a few seconds at 62K to cause failure.

 

[supra_89t]

Hopefully Holmes can chime in. In order to achieve 62kRPM on a 2700kv motor, the motor should have to see 23volts. So either, your battery is going to look like a balloon very soon, your motor is mislabeled (5000kv on 12.6v = 62kRPM), or the data is inaccurate.

Can you post up the rest of the screen so we can see the rest of the data along the bottom?

 

[whitrzac]

IIRC 4 pole motors report 2x the RPM that they are actually spinning.

Use smart sense VS sensored only. You still maintain the sensored startup but gain efficiency up top where the sensors are less useful. At higher RPM the sensors can give inaccurate readings do to the EMI from the motor too. "thumbsup"

 

[bigstu]

I might be wrong, but if I remember right the speedo is set up for counting RPM on a 2-pole motor. Since you are running a 4-pole motor, the speedo is taking the motor RPM and doubling it. Your magnet has 4 N and S segments, not the 2 that a normal 2-pole motor has. So when counting the magnetic changes, it is doubling your RPM.

Put the throttle back up to 100% and check for other issues. If you ran it through grass, that is quite a bit of resistance against a RC car. Check your gearing for tight gears that are binding. Look for drive line binding, putting too much angle on a drive shaft is a common problem on crawlers and will heat up a motor quickly. Also, the biggest issue I have seen, if you are running overdrive gears in the front and under drive gears in the back, on a heavy scale truck , it causes the drive line to bind when on high traction surfaces and make a LOT of heat in a motor quickly. I went from a OD/UD set up to UD/UD and my motor temps went down drastically. Literally from almost burning down a motor to running a 13.5 brushless on 3s with no issues.

 

[351Beno]

kv x volts= rpm

 

[MattySlimz1987]

Hopefully Holmes can chime in.  In order to achieve 62kRPM on a 2700kv motor, the motor should have to see 23volts.  So either, your battery is going to look like a balloon very soon, your motor is mislabeled (5000kv on 12.6v = 62kRPM), or the data is inaccurate.

Can you post up the rest of the screen so we can see the rest of the data along the bottom?

Yes, I can get a bigger picture when I get home today. The battery that was run was a 3200mah 30c discharge 3s Venom battery. I've also ran a 3800 Gens Ace 4s in this set up but did not take readings and did not go full throttle for long on that battery much either.

IIRC 4 pole motors report 2x the RPM that they are actually spinning.

Use smart sense VS sensored only. You still maintain the sensored startup but gain efficiency up top where the sensors are less useful. At higher RPM the sensors can give inaccurate readings do to the EMI from the motor too.;

Thanks! I hope that is the case for 2x's the reading. I've always had it set to SmartSense.

I might be wrong, but if I remember right the speedo is set up for counting RPM on a 2-pole motor. Since you are running a 4-pole motor, the speedo is taking the motor RPM and doubling it.  Your magnet has 4 N and S segments, not the 2 that a normal 2-pole motor has.  So when counting the magnetic changes, it is doubling your RPM


Put the throttle back up to 100% and check for other issues.  If you ran it through grass, that is quite a bit of resistance against a RC car. Check your gearing for tight gears that are binding Look for drive line binding, putting too much angle on a drive shaft is a common problem on crawlers and will heat up a motor quickly; Also, the biggest issue I have seen, if you are running overdrive gears in the front and under drive gears in the back, on a heavy scale truck , it causes the drive line to bind when on high traction surfaces and make a LOT of heat in a motor quickly; I went from a OD/UD set up to UD/UD and my motor temps went down drastically. Literally from almost burning down a motor to running a 13.5 brushless on 3s with no issues.

I do have a Robinson 13t pinion tbat will fit as its an 1/8th inch bore and 32 pitch. I can try that and than see the results, hopefully that will be better. The 13t will be a drop down from the currently stock 15t. Ring and spool gears are the stock Axial"s, was only going to upgrade later down the road if the locker or gears fail.

I'm still worried about setting it back to 100%..

 

[MattySlimz1987]

kv x volts= rpm

The 2×'s the reading is starting to make more sense now with the type of battery I'm running. 3200mah, 3s (11.1)

 

[R_2]

The 2×'s the reading is starting to make more sense now with the type of battery I'm running. 3200mah, 3s (11.1)

Valuable information for me too.. Yesterday I was running and setting up my new Mamba X + 4600kv sensored motor (with 3S battery..) I noticed from the log that max rpm had been 109000 wich was little suprising.. Now calculating it was quite exactly double "thumbsup"

 

[Thomas Porfert]

Following up on what others have already stated, you are seeing 2x the actual mechanical RPM. The Graph Viewer by default is set for a 2-pole motor, this will result in 2x the RPM output for a 4-pole motor. The ESC is recording electrical RPM and doesn't know (or need to know) the number of magnetic poles your motor has to actually run. So the data in the log is the electrical RPM and the graph viewer needs to be told the number of magnetic poles.

You can change the number of poles within the Graph Viewer so it displays the correct RPM.

In the Graph Viewer, go to Edit > Change Motor Pole/Count Gearing. This will open the "Motor and Gearing Information" dialog box. Use up the arrow on the "Magnetic Poles in Motor" and change it to "4"; click "Ok" and the RPM values should now be correct.

Thomas Porfert
Tech Support
Castle Creations

 

[MattySlimz1987]

Following up on what others have already stated, you are seeing 2x the actual mechanical RPM. The Graph Viewer by default is set for a 2-pole motor, this will result in 2x the RPM output for a 4-pole motor. The ESC is recording electrical RPM and doesn't know (or need to know) the number of magnetic poles your motor has to actually run. So the data in the log is the electrical RPM and the graph viewer needs to be told the number of magnetic poles.

You can change the number of poles within the Graph Viewer so it displays the correct RPM.

In the Graph Viewer, go to Edit > Change Motor Pole/Count Gearing. This will open the "Motor and Gearing Information" dialog box. Use up the arrow on the "Magnetic Poles in Motor" and change it to "4"; click "Ok" and the RPM values should now be correct.

Thomas Porfert
Tech Support
Castle Creations

Very good to know. Thank you sir! The Castle Link (Feild card version) did come with a little info card, but did not go into detail about its actual progam that needs to be downloaded if you want to connect to pc. I should have took more time and checked all the options in the upper taskbars before freaking out. Big sigh of relief. Not concerned about throwing my 4s battery in now either. Thanks again.

I will probably go back and change power output to 90% now that I know its only running 31,000 rpm (would like to get the most out of using a brushless motor) and change the setting to 4 pole. Also, switch out the stock 15t pinion for a 13t and see how that perform's.

 

[MattySlimz1987]

I might be wrong, but if I remember right the speedo is set up for counting RPM on a 2-pole motor. Since you are running a 4-pole motor, the speedo is taking the motor RPM and doubling it. Your magnet has 4 N and S segments, not the 2 that a normal 2-pole motor has. So when counting the magnetic changes, it is doubling your RPM.

Put the throttle back up to 100% and check for other issues. If you ran it through grass, that is quite a bit of resistance against a RC car. Check your gearing for tight gears that are binding. Look for drive line binding, putting too much angle on a drive shaft is a common problem on crawlers and will heat up a motor quickly. Also, the biggest issue I have seen, if you are running overdrive gears in the front and under drive gears in the back, on a heavy scale truck , it causes the drive line to bind when on high traction surfaces and make a LOT of heat in a motor quickly. I went from a OD/UD set up to UD/UD and my motor temps went down drastically. Literally from almost burning down a motor to running a 13.5 brushless on 3s with no issues.

Going back to what you are saying about the slight heat issue, yes the trans is slightly tight (not mesh). The Scx10 ii kit trans came with top shaft play and needed a very small shim to keep the grinding down and/or tighten up play. I still have a little play, but the 6'oclock rotation noise is gone which was my main concern with that issue, not so much the play.(Have video of prior noise upon request) Now with that small shim in there, the trans does have more resistance, thus causing more heat. I dont think this light rig would cause this motor to get anywhere near hot. Only solution to this maybe would be to put in the VP Top Shaft, I will get it, but have to find it in stock somewhere..first is to install the 13t pinion. any other suggestions will be taken to the bench for testing

 

[Dbx]

If the shim is making a the trans tight (which it will), take it out. If your trans is anything like mine, there is no room for a shim in there. Grind or file the corner off the larger lower gear to correctly clear the shoulder on the smaller input gear. You'll get a quiet, free running trans that way.

 

[bigstu]

Another thing to think about, I am running a 13.5t Tekin motor on my 10+lb scaler. To be able to run for extended time periods and not worry about smoking the motor, I changed to 48 pitch gears. And I run a 13-87 gearing on my trans, then have under drive gears in both axles. With this combo I can run in just about any condition and with no worries. And I'm if you say, what about mud and water? This is the solution.

TowerHobbies.com | Robinson Racing GEN3 Unit Hi Perf 87T 48P SCX10

 

[MattySlimz1987]

If the shim is making a the trans tight (which it will), take it out. If your trans is anything like mine, there is no room for a shim in there. Grind or file the corner off the larger lower gear to correctly clear the shoulder on the smaller input gear. You'll get a quiet, free running trans that way.

I will attempt to file that little extra metal that sticks out from the hole (bore) and rubs the shoulder of the parallel small gear here soon. I will just file it my best with these stick files in the tool box or maybe use an angle grinder? I don't own a table grinder or vise so I'm hoping a hand held angle grinder will work.

*This next paragraph is just a thought* If I still have binding and/or noise when I put this back together, I'm dishing out the whopping 13.99 for the VP top shaft. I'm pretty sure it does not come with the large gear that I believe that should be corrected and strengthened, but rather, it should have a corrected smaller gear that doesn't fade out like the current one, so it will not spin and hit hit that large gears existing metal that everybody is taking off. An idea for one of these companies would be to make a complete "Trans Perfection kit" for this since it's obviously so common. Include the exact shim and proper shaft specs but ALSO include a improved smaller gear thats on the top shaft. (Selling the small corrected gear instead of a revamped larger gear without the extra metal , is just a cost saving option) I'll have to check out SSD or Xtraspeed* and see if there's any last resorts. The 2 speed kit from SSD comes with some gears that I could steal and replace it with. But than that would be pointless, paying for the whole 2-speed kit, it might as well be put to use right? Could just gear it down even more and find a matching UD front and rear, have a 2-speed on the fly. (Probably would be the only person running a brushless 2-speed in this particular rig, as most people would say its totally not necessary) Yea, sure its just another thing to go wrong, but the truck is not comped etc. plus it wouldn't be a big deal pulling it out if something decides to not cooperate, as its been torn apart more times than it should have for being a couple month old rig. I dug into the rtr Twin Hammers 2-speed and looks like a very simple and tough unit. I can slam it into 2nd with a little more than half throttle on the TH and it grabs.

Sure if the kinks are worked out with that kit either (if there even are any) as I've researched it and found 1st gear is smooth as silk, but some have found that 2nd makes some pretty noticeable noise. Claims are; that the kit does not come with instructions so the noise could very well be consumer fault. Any input from #SSD on that one would be very cool, such as an update? Again this is all just speculation and off topic rambling, but figured I would get somebodys attention that DOES care about noise and binding with this new trans. I've noticed the noise and play doesn't bother most people.

 

[Dbx]

It's the outside edge that interferes with the shoulder. You should be able to file it down ok. This sorted my trans out.


I have the SSD 2 speed. I wish i'd not bothered. I love high speed with my other rigs, but the D90 i've built is purely a crawler/trail rig. I have a puller pro 2700kv in there too, and 2 speed just isn't needed for me. Anyway, the point is, the SSD kit replaces the bigger gear.... but it had the exact same issue, and i had to grind the corner of that gear too.

 

[MattySlimz1987]

Ok I see now, I was thinking it was the extra metal coming out from around hole. Thankyou for the clarification. I would have taken it out and filed down the wrong area. This picture here, should be in the thread all about how to fix the shaft play/fix grinding for the 10 ii.