Holmes HObby 3100kv heating up issue

[JDIRCC]

I appreciate the input. No I havent checked the temps yet but I am borrowing a temp gun tomorrow. And a pinion that small? I thought that would.increase the heat.

[dna4engr]

Originally Posted by JDIRCC

I appreciate the input. No I havent checked the temps yet but I am borrowing a temp gun tomorrow. And a pinion that small? I thought that would.increase the heat.

Nope. The verbiage around gear ratios is kinda backwards. A "taller" gear ratio actually means a smaller total ratio (the spur and pinion are closer together in size). Taller ratios give you more speed and more heat, especially when crawling. A taller ratio gives you more tire rotations per motor rotation, which is why it's faster.
A "lower" ratio has a bigger gap between the pinion and spur size. This results in a bigger number for the ratio. Lower ratios give you less speed, more torque, and lower temps. You get less rotations if the tire for every motor rotation.

Gear ratios are a measure of the gear reduction in the system. In the equation for your rig it goes like this.

56/14=4/1
Axial trans=2.6/1
Axles 38/13= 2.92/1
Total gear reduction = 4*2.6*2.92=30.4/1

So for every rotation of the motor you divide by the ratio (gear reduction) to get the rpm the axle is spinning at.
3100kv*11.1v=34410 rpm at motor
34410/30.4=1132 rpm at the axle (tire)

Lowering your pinion to 9 has the effect of lowering the rpm at the tire.

56/9= 6.22
Trans=2.6
Axles =2.92
Total gear reduction= 47.3/1
Now we have. 34410/47.3=727.5 rpm at the axle (tire).

That's 36% reduction in rpm at the tire. This translates to less load on the motor so it can run cooler and not generate the heat you are having. Gearing high is great for racing when speed is the only thing. Gearing low with the right motor is key for crawling.

Hope this helps,
Dna

[JDIRCC]

Thanks for the input. I def have a Bette understanding of how that works on these. Im a mechanic by trade and have done gear.changes on teucks and crawlers.before but not with that kind of understanding. I ordered a few different p inions and will go from there once they come in.

[JDIRCC]

Ok. Got the 9t pinion on there and did some testing. Esc heated and I checked it with laser temp gun. It was right at 100°f but the fan kicks in and kept it round the low 907s and upper 80s. The motor itself said 87° and didnt fluctuate much at all. Is that an ok temp dor the esc though? And I might add that that was with ALOT of full throttle hill climbing.

[allanon1965]

Those temps are fine as frog hair

[dna4engr]

Yea, those temps are low by normal standards. So you are on the right track.

I just installed my BLS 540 in a 10 lb scaler turning 2.2 Pitbulls. 9/56 pinion/spur, 43/13 axle gears, metal gear axial trans (total ratio about 54/1). Running on 3S lipo. I ran through several scenarios in my back yard and my mini crawling course. After about 10 min of crawling, temps on different parts of the motor were between 120*F and 150*F. Then I did some full throttle laps in the grass (approx 5" tall). After about 3-4 minutes I measured anywhere from 90*F to 160*F. The closer I get to the trans mount the warmer it got. I'm using a laser temp gun for these measurements.

I will say that this motor is super super torquey for a 2 Pole. There is no lying about that. Actually quite impressive. The super low speed wasn't exactly where I wanted it but I haven't tried reprogramming my MMP to tailor it to this motor. I normally run a 2300kv Roc412 running the same setup as above but a 12t pinion for a total ratio of 40/1. I'm going to throw the Tekin back in and see what differences I can tell in heat. Never actually measured that one. Right now my gut says this will be going into my 1.9 scaler.

Dna

[JDIRCC]

Originally Posted by dna4engr

Yea, those temps are low by normal standards. So you are on the right track.

I just installed my BLS 540 in a 10 lb scaler turning 2.2 Pitbulls. 9/56 pinion/spur, 43/13 axle gears, metal gear axial trans (total ratio about 54/1). Running on 3S lipo. I ran through several scenarios in my back yard and my mini crawling course. After about 10 min of crawling, temps on different parts of the motor were between 120*F and 150*F. Then I did some full throttle laps in the grass (approx 5" tall). After about 3-4 minutes I measured anywhere from 90*F to 160*F. The closer I get to the trans mount the warmer it got. I'm using a laser temp gun for these measurements.

I will say that this motor is super super torquey for a 2 Pole. There is no lying about that. Actually quite impressive. The super low speed wasn't exactly where I wanted it but I haven't tried reprogramming my MMP to tailor it to this motor. I normally run a 2300kv Roc412 running the same setup as above but a 12t pinion for a total ratio of 40/1. I'm going to throw the Tekin back in and see what differences I can tell in heat. Never actually measured that one. Right now my gut says this will be going into my 1.9 scaler.

Dna

I did another test run today. And before i broke my tie rod (again) i got a few good tests and temps in. The MMP is still heating up quick (3-5 mins) but the temps don't break too much over 100 degrees at the highest and the fan does its job of keeping it at those temps and lowering them quickly as i ease off or stop running. I checked the motor again and checked the end of the bell where you can see the bearing and I was getting temps at the hottest at around 140 degrees and it was a decently hot day today in the 90's. So with John from HH saying the normal run temps are up to 160 i think its ok. It still worries me that i am going to fry my MMP. But i think it will shut itself down if it gets to that point.

Another thing i have noticed is that even when running my 3s 5000mah lipo i still am seeming to run through the batter life rather quickly. it may not be a issue with the electronics at all considering i have given this set of 3s batteries the worst torture tests by not waterproofing them and running them through virtually any and all conditions. So I'm leaning toward it just being a bat issue there. Have you noticed anything of that nature with yours?

[dna4engr]

I haven't run a complete pack through yet so I can't say on the life. I switched back to my 2300kv Roc412 and the temps were much cooler 80-90*F. This time it was geared 14/56 at the trans. The speed still didn't match the Holmes Hobbies BLS540 but the cooler temps are what I need for this scaler. The BLS is definitely going in my 1.9 scaler that is is only 7 lbs. It will give that one some torque and speed it needs.

What are you comparing your run times to? A brushed motor or a different brushless.

Dna

Originally Posted by JDIRCC

I did another test run today. And before i broke my tie rod (again) i got a few good tests and temps in. The MMP is still heating up quick (3-5 mins) but the temps don't break too much over 100 degrees at the highest and the fan does its job of keeping it at those temps and lowering them quickly as i ease off or stop running. I checked the motor again and checked the end of the bell where you can see the bearing and I was getting temps at the hottest at around 140 degrees and it was a decently hot day today in the 90's. So with John from HH saying the normal run temps are up to 160 i think its ok. It still worries me that i am going to fry my MMP. But i think it will shut itself down if it gets to that point.

Another thing i have noticed is that even when running my 3s 5000mah lipo i still am seeming to run through the batter life rather quickly. it may not be a issue with the electronics at all considering i have given this set of 3s batteries the worst torture tests by not waterproofing them and running them through virtually any and all conditions. So I'm leaning toward it just being a bat issue there. Have you noticed anything of that nature with yours?

[JDIRCC]

Originally Posted by dna4engr

I haven't run a complete pack through yet so I can't say on the life. I switched back to my 2300kv Roc412 and the temps were much cooler 80-90*F. This time it was geared 14/56 at the trans. The speed still didn't match the Holmes Hobbies BLS540 but the cooler temps are what I need for this scaler. The BLS is definitely going in my 1.9 scaler that is is only 7 lbs. It will give that one some torque and speed it needs.

What are you comparing your run times to? A brushed motor or a different brushless.

Dna

Honestly its just compared to my HH crawl master on 3s. but is still thought i would get a lot of run time out of it. But also to be honest i don't even know what kind of run times i should be getting on a brushless running 3s.

I really would like to try a roc412 motor. I enjoy trying new products and i haven't tried any tekin products. I do really like my HH brushless though and i can second what you said on torque and wheel speed. my wraith probably ways a lil over 10lbs if not more. And it has no trouble bashing around. I will also add that after i took the advice and dropped my pinion down to a 9t that i honestly haven't found too much that it won't climb or crawl up. I'm thinking of under driving the rear to better that even more.
I recall you saying that yours didn't have the low crawl speed that you were wanting. mine does a fairly decent crawl with a little tuning. Definitely as good as one of Johns hand wound brushless motors lol. In my opinion you can't beat his brushed motors.

[67mustang]

FYI, I have a roc412 1200kv and 1800 kv. I can run/"bash" at constatnt throttle for 2000mah and I can hold my finger on the motor. I don't know how hot that is, but in usual trailing situations they barely get warm and never once even hiccup or a 'glitch'. Super reliable.

[JDIRCC]

Originally Posted by 67mustang

FYI, I have a roc412 1200kv and 1800 kv. I can run/"bash" at constatnt throttle for 2000mah and I can hold my finger on the motor. I don't know how hot that is, but in usual trailing situations they barely get warm and never once even hiccup or a 'glitch'. Super reliable.

Whats the wheels speed and crawlability like?

[67mustang]

Great...but my rigs are on 40 series tires so wheelspeeds will differ. I run 3s.

1200 kv at any gearing will strip something before it ever thinks about stalling. When I went to an 1800kv and 9:1 gearing and I can get 8" rok loks to really rip. You really won't see what kind of torque these motors have to offer in a crawler setup. They will straight rip and be totally efficient. I could strap 5lbs to my rig and it would still rip. The 3100/3300 have gotten quite a following on 2s, but if I had a 2.2 wraith, I would go with a 2300 on 3s. It would still rip and have more low end control/torque. This horse has been beat, but I don't think people realize how easy a life these motors live in these crawlers. Knowing that, I don't know if I would have any patience with a motor running hot.

[JDIRCC]

Originally Posted by 67mustang

Great...but my rigs are on 40 series tires so wheelspeeds will differ. I run 3s.

1200 kv at any gearing will strip something before it ever thinks about stalling. When I went to an 1800kv and 9:1 gearing and I can get 8" rok loks to really rip. You really won't see what kind of torque these motors have to offer in a crawler setup. They will straight rip and be totally efficient. I could strap 5lbs to my rig and it would still rip. The 3100/3300 have gotten quite a following on 2s, but if I had a 2.2 wraith, I would go with a 2300 on 3s. It would still rip and have more low end control/torque. This horse has been beat, but I don't think people realize how easy a life these motors live in these crawlers. Knowing that, I don't know if I would have any patience with a motor running hot.

I hear that but i wouldn't say mine has had an easy life. i use my wraith as my expensive don't give no **** rig i crawl it, bash it, bog it, sink it, anything and everything. I don't care that i drive that one throttle happy like a complete noob. Thats why i have built it the way that i have. Now my scx10 g6 is my scaler and crawler. i drive it way more conservative. Im currently waiting on a huge thing of parts for another scaler scx based build. And after your words i think I'm gonna throw the tekin setup in this one and try it out and see what all i can tear up.

[dna4engr]

Like JRH said in a prior post, this motor runs hot. None of my Tekin motors run hot (2 Pole or 4 Pole). You kind of have to weigh the performance vs. cost.

These are what I have or have used - All on 3S
Tekin Pro4 3500HD - $160
Tekin Roc412 2300 - $150
Tekin Redline 13.5 (w/ hi torque rotor) - $70+30
Tekin Redline 17.5 - $70
HH BLS540 - $80

Torque:
The HH BLS540 equals the Roc412 in torque (not measured, perception)
The 13.5 with rotor was really good but struggled under severe loads
17.5 is a great little motor but it is not very torquey
3500HD is just stupid

Speed:
BLS540 is close to the 13.5 and faster than the 17.5 and the 2300 (it should be)
The 2300kv Roc412 has one advantage - it can run on 4S and I have done that. It easily meets any speed expectation then.
The 3500HD surprisingly wasn't as fast as the kv would make you think. I didn't run a tach on it, but I would say the BLS540 is close.

Run Time (on 3S 5000mah Gensace)
Tekin Redline (both) - 2-4 hours depending on how its driven
Roc412 - 2-3 hours depending on driving style
BLS540 - TBD
3500HD - 1-2 hours (it's just too hard not to run full throttle when you have that speed )

Temp:
Redlines can get warm but not "hot"
3500HD gets warm but no too much
Roc412 is a cool cucumber
BLS540 does exactly what John says, it gets upto and runs close to 160. I am uneasy with this even though I know it's "okay"

Low speed crawling:
Redlines and Roc412 were easy to tune with an MMP and get superb startup and control.
3500HD became acceptable with a lot of tuning
BLS540 was not as good as the Roc412 with the same tune. Will be tweaking this in my 1.9 rig (it's replacing the 17.5 Tekin).

Overall:
The Gen 1 Tekin motors are harder and harder to find (Gen 2 have vent holes so not great for a scaler in the mud). So comparing to the available Tekin motors, the BLS540 is a great compromise if the temp stays in the range that JRH says it should be. Almost half the price and extremely good performance.

I've heard good things about the Hobbywing 3656SD 3400kv, but I've never run one so I can't comment.

Dna

Originally Posted by JDIRCC

I hear that but i wouldn't say mine has had an easy life. i use my wraith as my expensive don't give no **** rig i crawl it, bash it, bog it, sink it, anything and everything. I don't care that i drive that one throttle happy like a complete noob. Thats why i have built it the way that i have. Now my scx10 g6 is my scaler and crawler. i drive it way more conservative. Im currently waiting on a huge thing of parts for another scaler scx based build. And after your words i think I'm gonna throw the tekin setup in this one and try it out and see what all i can tear up.

[Shinjari]

I have the HH BLS and agree the low end is a little lacking and runs warmer than I'd like. I was considering a ROC 2300kv. Granted the HH is in an ultra4 so it doesn't need to crawl nearly as slow as my dedicated scalers. What tuning were you running in your MMP for the ROC 412 (2300)?

[evan03]

I would chase all solder connections.
Even a bad connection on the battery to esc can cause all kinds of havoc


Yes no patience for hot running motors.

Just toss a 900 kv 800 watt out runner in it. Itl run cold and smooth with enough power to peel your tires of the wheels and eat your mip's for break fast.

Most brushless motors can handle 160 but I won't do it. I like 80-90 temps. That's just way to hot special when you factor in 105 outside air temps. They just won't last long. There's a reason Holmes is working on making then run cooler

[JDIRCC]

Originally Posted by evan03

I would chase all solder connections.
Even a bad connection on the battery to esc can cause all kinds of havoc


Yes no patience for hot running motors.

Just toss a 900 kv 800 watt out runner in it. Itl run cold and smooth with enough power to peel your tires of the wheels and eat your mip's for break fast.

Most brushless motors can handle 160 but I won't do it. I like 80-90 temps. That's just way to hot special when you factor in 105 outside air temps. They just won't last long. There's a reason Holmes is working on making then run cooler

I don't like the running hot at all but i like the performance of this motor so much so far that I'm just gonna run it and see what happens. I do have this want to try one of the HH high end brushed motors. I had so much luck with the 28t i have that the better end models can only be better. But i may save the brushed motors for the scx10. i enjoy beating my wraith too much.

[JohnRobHolmes]

Everything we build the motor with is 200c rated materials. 160f is hardly warm in reality. But, we are still improving the motor to reduce temps and allow for higher output power and torque.

[JDIRCC]

Originally Posted by JohnRobHolmes

Everything we build the motor with is 200c rated materials. 160f is hardly warm in reality. But, we are still improving the motor to reduce temps and allow for higher output power and torque.

I didn't figure it was a too warm to be honest. And with your motors i honestly can say that your motors will last through a lot of it. I have had one of your 28t brushed motors smoke on me twice and it still hasn't died. Looses power when super hot yes but let it cool down and its back at it like its new. Freaking amazing. I recently proved this when we spent a good 6hrs crawling at a local spot. at the end of the almost 6 hrs of continuous beating and swapping batteries lol we came to a hill out there we call The Stairway to Heaven. I wish a camera would do the justice for the steep angle this hill is. Its nearly impossible to walk up and would be a crazy line for a 1:1 bouncer to try. Its easily 100yrds long as well as super steep. But back to my point. Out of the four of us there, mine was the only one to make it all the way to the top. Two of the others overheated well before making it anywhere near the top and there MMP's shut them down. Mine kept consistency all day and all the way through the end of that hill.

After that day i took that motor out and put it on the shelf lol. it deserves a break

[Calderwood]

Originally Posted by evan03

I would chase all solder connections.
Even a bad connection on the battery to esc can cause all kinds of havoc


Yes no patience for hot running motors.

Just toss a 900 kv 800 watt out runner in it. Itl run cold and smooth with enough power to peel your tires of the wheels and eat your mip's for break fast.

Most brushless motors can handle 160 but I won't do it. I like 80-90 temps. That's just way to hot special when you factor in 105 outside air temps. They just won't last long. There's a reason Holmes is working on making then run cooler

Because 900kv is comparable to 3100kv how?