donaldsneffe
Rock Crawler
Hey guys,
Made some tests and measurements with 550 brushed 5-slot crawler motors during the last months and thought, some of you could be interested in the results. I did also make and upload two videos about those tests, the first one turned out far too long (2 ½ hrs), so I cut a short version (30 min); you’ll find the links to the videos at the end of this posting.
Some words first: I know the tests wont withstand scientific standards, I know setup and equipment are not professional, I know force should be given in Newton and not in kilogram (but everyone understands kilogram
), etc. etc. – but this is a hobby forum with hobby people and my posting is not a scientific publication. I find the results interesting, and I guess they could also help other hobbyists to choose their budget motor.
I used a Holmes Hobbies Crawlmaster Sport 550 12t and a Surpass Hobby 550 Crawler Motor 12t, both 5-slot motors.
Holmes Hobbies website says 12t 550 5-slot motors are comparable to ca. 30t 540 3-slot motors in speed, and since I also had two new ones of those here, I included a Holmes Hobbies Trailmaster Sport 540 27t and a supercheap 35t 540 China motor (I had paid only about 8 bucks for this motor incl. shipment some time ago).
For the driving tests I used a Reely Free Men Kit chassis (similar to SCX10 2, mega-super popular here, not known in America or Asia) with stock 13t pinion, a Hobbywing Quicrun 1080 ESC, cheap China metal beadlocks and tires and a 5000 mAh 2s Lipo. I put lead weight to the chassis, so the overall weight (incl. battery) was about 3.4 kg, an “average scale crawler”.
All four motors tested were brand new, never had run outside and had been broken in for about 10 min at 2 V; equipped with AWG 14 wires and 4 mm gold plated plugs.
At the time I bought the 550 motors both were 19.99 US$.
However, I paid 15.99 for the Surpass incl. shipment, using some BG points, and 24.50 for the Holmes with shipment from the US to Europe. But this price difference is not relevant, and also strongly depending on where you live. Nevertheless, the Surpass motor is much easier available for people outside the US than the Holmes motors (Banggood, Ali, Ebay, …), and the Holmes motors are often out of stock.
The Surpass motor comes well packed in a box and with foam, and with 14 AWG wires and gold plated plugs (unfortunately 3.5 mm and not 4 mm – I changed to 4 mm because all my “larger cars” ESCs and motors do have 4 mm plugs).
The Holmes Hobbies motor comes packed only in a simple plastic bag. In my motor the “black” soldering tab was bent 90° outwards. No big deal, I thought it was damaged during transport. But later I bought two more Holmes Hobbies Crawlmaster Sport (540), and those two motors also arrived with 90° bent “black” tab, but inwards. The “red” tab was totally fine in all motors. So maybe this is on purpose, or simply by chance?
The Surpass motor comes with two ball bearings, while the Holmes motor comes with one bearing and one bushing.
The Holmes motor does have a fan inside, the Surpass motor not.
The shafts of the two China motors are 2 mm longer than the shafts of the Holmes Hobbies motors. For my Reely Free Men pinion (and in the chassis) the Holmes shafts are more than 2 mm too short. That’s not a big deal, and I know that the China motor shafts are too long for some other models.
Weight of both motors is on spot, 215 g, as specifications say.
All in all the Surpass motor looks “shinier” and better built than the Holmes motor (but this is only the look).
The Surpass 550 is rebuildable, and brushes can be changed. The Holmes Hobbies Crawlmaster Sport is a sealed can motor, so one cannot take a look inside (by simply opening some screws).
Timing can be changed in the Surpass motor, not in the Holmes motor.
Of course I took a look inside the Surpass motor, … 2 magnets, some blue trim weight, … I am not a specialist and not the person to judge the inside build quality.
Tests und measurements:
Timing:
First I checked timing of both motors, both should come with timing 0°.
Therefore I checked the amp-draw on a given voltage in forward and reverse direction, and I checked the rpms in both directions on a given voltage with a 0° propeller (foam sanding stick) and an optical heli-tacho.
Results:
The Holmes Hobbies Crawlmaster Sport 550 came with timing 0 spot on, perfect. But in the Surpass 550 motor timing was extremely retarded, nevertheless the scale on the motor showed 0°. I had to put timing on 7° (scale on motor bell) to get 0° timing. After this I disassembled the Surpass motor, before I had marked the sweet spot (0 timing) on bell and endcap. After reassembling the motor and turning the endcap to the “sweet spot”, timing again was retarded. Finally I had to put the motor to 9° (scale) to get a timing of 0 in the Surpass motor.
No Load Amp-draw:
I measured the Amp-draw of the motors on the bench from 1 V – 13 V with a lab power supply.
Here the results of all four motors:
Results:
The Surpass motor drew a lot more ampere than the Holmes Hobbies Crawlmaster Sport 550, but also the Holmes Hobbies Trailmaster Sport 540 drew a high amp, the cheap China 540 35t drew least.
The Holmes Hobbies Crawlmaster ran much calmer than the Surpass 550 motor. I did not have to fix the motor during the measurements on the work bench. The Surpass 550 motor showed a lot more vibrations, I had to fix it during measurements in higher voltages.
However, the amp-draw of the Surpass 550 motor was much more constant than the amp-draw of the Holmes Hobbies Crawlmaster Sport. In the Holmes Crawlmaster the display with Ampere never really settled down, there was always a slight up and down.
Ampere, rpm, temperature, max Voltage under load:
I measured Ampere and rpm with 0° propeller with (full) 2s and 3s Lipo batteries, at voltages from 1 V up to the maximum voltage the motor received at 2s and 3s.
Therefore I used a Hobbywing 1080 ESC and a servo-tester for regulation. I measured the Amp-draw between battery and ESC with an old Hobbyking Wattmeter, the voltage directly at the motor with a multimeter and rpm with an optical helicopter tachometer.
After testing I checked the temperature of both 550 motors with an IR-thermometer.
Here the results of the Holmes Crawlmaster Sport 550 (red/orange) and the Surpass 550 (blue) in a graph, with 2s and 3s Lipos. Right y-axis and dotted lines show the Ampere, left y-axis and full line the rpm at voltage (x-axis).
And here the results of all four motors tested, 2s, 3s, rpm, ampere:
Noticeable:
None of the motors received the voltage of a full 2s or 3s Lipo battery, 8.4 V or 12.6 V; maximum was about 7 V at 2s and about 10 V at 3s.
Sometimes the Hobbywing 1080 ESC shut off during those tests and then ran in a kind of “safety mode” (weaker than normal). Then I had to switch off the ESC and switch it on again, and everything was ok again.
All motors drew on same voltage more ampere with the 2s Lipo than they did with the 3s Lipo, and rpm was higher. I guess, this is because I used a rather old 1500 mAh 3s 30c Lipo for those measurements, and a rather new 25-30c 4000 mAh 2s Lipo. Not only c-rating, but also capacity will affect the power of a Lipo. Maybe the results would have been different, if I had used a small 60 – 120c 3s Lipo or a larger 3s Lipo.
The Holmes Crawlmaster Sport 550 always drew fewer amperes than the Surpass 550 motor at the same voltage and additionally ran on higher rpm.
The Holmes Hobbies Trailmaster Sport 540 27t drew a lot of amps, but did not (as I would have expected) show higher rpm than the other motors.
Positive surprise: The supercheap China 540 35t motor.
Temperature: After those tests the Surpass 550 motor was much hotter than the Holmes Hobbies 550 Crawlmaster Sport motor. The Surpass showed temperatures in the 60 degrees, maximum 71° C, while the Holmes stayed cool in the forties, maximum 49° C.
Pull force:
I made a simple winch and connected it to a luggage-scale. The motor was connected to the winch by a kardan-joint, “direct drive”.
I measured the pull force (in kg, not N ;-) ) of all four motors with 2s and 3s Lipos. Therefore I used the Hobbywing 1080 and the servotester for control.
I tested all four motors 12 times, 6 times with a 2s Lipo (3 times with a 4000 mAh Lipo and 3 times with a 5000 mAh Lipo) and 6 times with a 3s Lipo (3 times with a 1500 mAh Lipo and 3 times with a 3000 mAh Lipo).
All motors but the Surpass motor showed smoke signs at times, but not on each measurement; however, this seemed not to affect their performance. But after those tests the Surpass 550 motor, which showed no smoke, again was much hotter than the Holmes Hobbies Crawlmaster 550.
Here are the results shown in a graph:
Left y-axis pull-force in kg, right y-axis amp-draw. Each motor in a different colour, the left bars show the pull-force on 2s and on 3s, the right bars (black outline) the amp-draw on 2s and on 3s. Each bar shows the mean of the 6 measurements, error bar shows standard error, X shows the single highest value measured.
Noticeable:
The Holmes Crawlmaster Sport 550 was much stronger than the Surpass 550 5-slot motor, however, amp-draw was not higher but similar.
The Holmes Hobbies Crawlmaster Sport 550 was by far the strongest motor in those tests.
Highest „single pull“ by the Holmes Crawlmaster 550 in a 2s measurement (not 3s).
The Holmes Trailmaster Sport 540 pulled more kg on 2s than on 3s, but drew more amperes on 3s and showed the highest single value amp-draw of all motors tested.
The supercheap China 540 35t motor again did surprisingly well.
There is a small downside in those pull-tests:
Probably I should have let cool down the motors totally after each test, what I did not do. This seemed not to be a problem for 3 of the 4 motors tested, but the Holmes Hobbies Trailmaster Sport 540 seemed to get weaker by time (but drew more amperes).
...
Made some tests and measurements with 550 brushed 5-slot crawler motors during the last months and thought, some of you could be interested in the results. I did also make and upload two videos about those tests, the first one turned out far too long (2 ½ hrs), so I cut a short version (30 min); you’ll find the links to the videos at the end of this posting.
Some words first: I know the tests wont withstand scientific standards, I know setup and equipment are not professional, I know force should be given in Newton and not in kilogram (but everyone understands kilogram
), etc. etc. – but this is a hobby forum with hobby people and my posting is not a scientific publication. I find the results interesting, and I guess they could also help other hobbyists to choose their budget motor.I used a Holmes Hobbies Crawlmaster Sport 550 12t and a Surpass Hobby 550 Crawler Motor 12t, both 5-slot motors.
Holmes Hobbies website says 12t 550 5-slot motors are comparable to ca. 30t 540 3-slot motors in speed, and since I also had two new ones of those here, I included a Holmes Hobbies Trailmaster Sport 540 27t and a supercheap 35t 540 China motor (I had paid only about 8 bucks for this motor incl. shipment some time ago).
For the driving tests I used a Reely Free Men Kit chassis (similar to SCX10 2, mega-super popular here, not known in America or Asia) with stock 13t pinion, a Hobbywing Quicrun 1080 ESC, cheap China metal beadlocks and tires and a 5000 mAh 2s Lipo. I put lead weight to the chassis, so the overall weight (incl. battery) was about 3.4 kg, an “average scale crawler”.
All four motors tested were brand new, never had run outside and had been broken in for about 10 min at 2 V; equipped with AWG 14 wires and 4 mm gold plated plugs.
At the time I bought the 550 motors both were 19.99 US$.
However, I paid 15.99 for the Surpass incl. shipment, using some BG points, and 24.50 for the Holmes with shipment from the US to Europe. But this price difference is not relevant, and also strongly depending on where you live. Nevertheless, the Surpass motor is much easier available for people outside the US than the Holmes motors (Banggood, Ali, Ebay, …), and the Holmes motors are often out of stock.
The Surpass motor comes well packed in a box and with foam, and with 14 AWG wires and gold plated plugs (unfortunately 3.5 mm and not 4 mm – I changed to 4 mm because all my “larger cars” ESCs and motors do have 4 mm plugs).
The Holmes Hobbies motor comes packed only in a simple plastic bag. In my motor the “black” soldering tab was bent 90° outwards. No big deal, I thought it was damaged during transport. But later I bought two more Holmes Hobbies Crawlmaster Sport (540), and those two motors also arrived with 90° bent “black” tab, but inwards. The “red” tab was totally fine in all motors. So maybe this is on purpose, or simply by chance?
The Surpass motor comes with two ball bearings, while the Holmes motor comes with one bearing and one bushing.
The Holmes motor does have a fan inside, the Surpass motor not.
The shafts of the two China motors are 2 mm longer than the shafts of the Holmes Hobbies motors. For my Reely Free Men pinion (and in the chassis) the Holmes shafts are more than 2 mm too short. That’s not a big deal, and I know that the China motor shafts are too long for some other models.
Weight of both motors is on spot, 215 g, as specifications say.
All in all the Surpass motor looks “shinier” and better built than the Holmes motor (but this is only the look).
The Surpass 550 is rebuildable, and brushes can be changed. The Holmes Hobbies Crawlmaster Sport is a sealed can motor, so one cannot take a look inside (by simply opening some screws).
Timing can be changed in the Surpass motor, not in the Holmes motor.
Of course I took a look inside the Surpass motor, … 2 magnets, some blue trim weight, … I am not a specialist and not the person to judge the inside build quality.
Tests und measurements:
Timing:
First I checked timing of both motors, both should come with timing 0°.
Therefore I checked the amp-draw on a given voltage in forward and reverse direction, and I checked the rpms in both directions on a given voltage with a 0° propeller (foam sanding stick) and an optical heli-tacho.
Results:
The Holmes Hobbies Crawlmaster Sport 550 came with timing 0 spot on, perfect. But in the Surpass 550 motor timing was extremely retarded, nevertheless the scale on the motor showed 0°. I had to put timing on 7° (scale on motor bell) to get 0° timing. After this I disassembled the Surpass motor, before I had marked the sweet spot (0 timing) on bell and endcap. After reassembling the motor and turning the endcap to the “sweet spot”, timing again was retarded. Finally I had to put the motor to 9° (scale) to get a timing of 0 in the Surpass motor.
No Load Amp-draw:
I measured the Amp-draw of the motors on the bench from 1 V – 13 V with a lab power supply.
Here the results of all four motors:
Results:
The Surpass motor drew a lot more ampere than the Holmes Hobbies Crawlmaster Sport 550, but also the Holmes Hobbies Trailmaster Sport 540 drew a high amp, the cheap China 540 35t drew least.
The Holmes Hobbies Crawlmaster ran much calmer than the Surpass 550 motor. I did not have to fix the motor during the measurements on the work bench. The Surpass 550 motor showed a lot more vibrations, I had to fix it during measurements in higher voltages.
However, the amp-draw of the Surpass 550 motor was much more constant than the amp-draw of the Holmes Hobbies Crawlmaster Sport. In the Holmes Crawlmaster the display with Ampere never really settled down, there was always a slight up and down.
Ampere, rpm, temperature, max Voltage under load:
I measured Ampere and rpm with 0° propeller with (full) 2s and 3s Lipo batteries, at voltages from 1 V up to the maximum voltage the motor received at 2s and 3s.
Therefore I used a Hobbywing 1080 ESC and a servo-tester for regulation. I measured the Amp-draw between battery and ESC with an old Hobbyking Wattmeter, the voltage directly at the motor with a multimeter and rpm with an optical helicopter tachometer.
After testing I checked the temperature of both 550 motors with an IR-thermometer.
Here the results of the Holmes Crawlmaster Sport 550 (red/orange) and the Surpass 550 (blue) in a graph, with 2s and 3s Lipos. Right y-axis and dotted lines show the Ampere, left y-axis and full line the rpm at voltage (x-axis).
And here the results of all four motors tested, 2s, 3s, rpm, ampere:
Noticeable:
None of the motors received the voltage of a full 2s or 3s Lipo battery, 8.4 V or 12.6 V; maximum was about 7 V at 2s and about 10 V at 3s.
Sometimes the Hobbywing 1080 ESC shut off during those tests and then ran in a kind of “safety mode” (weaker than normal). Then I had to switch off the ESC and switch it on again, and everything was ok again.
All motors drew on same voltage more ampere with the 2s Lipo than they did with the 3s Lipo, and rpm was higher. I guess, this is because I used a rather old 1500 mAh 3s 30c Lipo for those measurements, and a rather new 25-30c 4000 mAh 2s Lipo. Not only c-rating, but also capacity will affect the power of a Lipo. Maybe the results would have been different, if I had used a small 60 – 120c 3s Lipo or a larger 3s Lipo.
The Holmes Crawlmaster Sport 550 always drew fewer amperes than the Surpass 550 motor at the same voltage and additionally ran on higher rpm.
The Holmes Hobbies Trailmaster Sport 540 27t drew a lot of amps, but did not (as I would have expected) show higher rpm than the other motors.
Positive surprise: The supercheap China 540 35t motor.
Temperature: After those tests the Surpass 550 motor was much hotter than the Holmes Hobbies 550 Crawlmaster Sport motor. The Surpass showed temperatures in the 60 degrees, maximum 71° C, while the Holmes stayed cool in the forties, maximum 49° C.
Pull force:
I made a simple winch and connected it to a luggage-scale. The motor was connected to the winch by a kardan-joint, “direct drive”.
I measured the pull force (in kg, not N ;-) ) of all four motors with 2s and 3s Lipos. Therefore I used the Hobbywing 1080 and the servotester for control.
I tested all four motors 12 times, 6 times with a 2s Lipo (3 times with a 4000 mAh Lipo and 3 times with a 5000 mAh Lipo) and 6 times with a 3s Lipo (3 times with a 1500 mAh Lipo and 3 times with a 3000 mAh Lipo).
All motors but the Surpass motor showed smoke signs at times, but not on each measurement; however, this seemed not to affect their performance. But after those tests the Surpass 550 motor, which showed no smoke, again was much hotter than the Holmes Hobbies Crawlmaster 550.
Here are the results shown in a graph:
Left y-axis pull-force in kg, right y-axis amp-draw. Each motor in a different colour, the left bars show the pull-force on 2s and on 3s, the right bars (black outline) the amp-draw on 2s and on 3s. Each bar shows the mean of the 6 measurements, error bar shows standard error, X shows the single highest value measured.
Noticeable:
The Holmes Crawlmaster Sport 550 was much stronger than the Surpass 550 5-slot motor, however, amp-draw was not higher but similar.
The Holmes Hobbies Crawlmaster Sport 550 was by far the strongest motor in those tests.
Highest „single pull“ by the Holmes Crawlmaster 550 in a 2s measurement (not 3s).
The Holmes Trailmaster Sport 540 pulled more kg on 2s than on 3s, but drew more amperes on 3s and showed the highest single value amp-draw of all motors tested.
The supercheap China 540 35t motor again did surprisingly well.
There is a small downside in those pull-tests:
Probably I should have let cool down the motors totally after each test, what I did not do. This seemed not to be a problem for 3 of the 4 motors tested, but the Holmes Hobbies Trailmaster Sport 540 seemed to get weaker by time (but drew more amperes).
...
