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View Full Version : New Motors - Open Letter to Everyone


Hood
2007.06.20, 03:49 PM
This came from one of the top HFAY racers that is very knowledgable about motors and building them for many years. He was into slotcars and is very good with them.

I don't know what to make of it, but here it is..


I decided to test out the new OLPS motors last night. In short, Very Dissapointed! I selected and installed the first one with the same gearing, 8/43, as I run with my 'Atomic Stock' motor. It was no faster than the factory 'Kit' motor around my 2L track and was very VERY hot after only a few minutes. I tried gearing all the way down to 6/48 and while performance increased, the motor continued to run very hot. At his point a started looking for the problem. I put an 'Atomic Stock'
motor, geared 8/43, in the car and it hauled ass...as expected. This verified that there was a problem with the new motor and not the car. I removed the brushes to check the motor for internal drag and found that the arm would not even come close to spinning as it should. Next step, pop the end bell and investigate. Here is what I found:

1. Too many axial play shims on the arm causing a large axial preload on the bearings and lots of drag.
2. After a couple of shims were removed the motor still did not spin as freely as it should. I found that the bearing in the can was installed at an angle. I removed and
reinstalled this bearing correctly using at slot car tool designed for this purpose.
3. Found the same problem with the end bell bearing. Corrected that also.
4. I noted the advanced timing of the com. I estimated it to be 30+ degrees. I find this unusual as all other Mini-Z motors I own are timed at, or very close to, Zero.

After correcting all these problems, except the non-adjustable timing, I reinstalled the motor in my car. It now ran much better but still very hot. The advanced timing of this motor, along with other factors to be discussed later, obviously needed gearing below what is possible on a Mini-Z.

These findings led me to pop the top on the remaining four motors that I had purchased. The axial shimming and bearing alignment problems were present in all four units to varying degrees. Non were within what I would consider to be acceptable assembly tolerances. I corrected all deficiencies found with respect to axial shimming and bearing alignments and reasembled these motors.

What really shocked me was the com timing variation found. As it turns out, the first one I tried running had the most timing. That figures, I installed the one that sounded the fastest when tested at 4.0 volts on my power supply. One motor looked to be about zero degrees and the remaining two looked to be somewhere between these two. I will try the one with the least timing tonight and see how it works.

The last problem I found was with the week magnets being used. When you combine a lower turn arm with advanced timing AND week magnets, you get
a motor with a very high RPM power band. This is OK as long as you can
gear the car as needed. Unfortunately, the motor I tested needed gearing lower than what is possible on a Mini-Z. Another way around this problem is to use much stronger magnets. This will bring the motors power band way down the RPM scale. This is why other Atomic Motors work well. Although Atomic offers many motors with even less turns on their armatures, they all have very mild timing and much stronger magnets.

Did anybody do any testing on these motors before deciding to use them?

Please send me Robin's And Dusty's E-Mail addresses so I can send them a copy of this. I also feel that a copy should be posted in the 'How Fast Are You' website but do not have a Log On ID yet. I believe Robin can do this as I have read postings of his there before.
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Good luck with yours,

Hood
2007.06.20, 03:52 PM
I just got another email from Bill personally..

Fellow racers,

By now, I hope you have read my findings on the 'New' HFAY motors. I hope you don't have the same problems with your's that I found in mine.
But, assuming that Dusty selected my five at random, the odds that yours have the same problems are pretty good. Here are a few ways you can check the status of your motors:

The first and easiest thing to check is the armature end play and bearing alignment. You should be able to easily move the armature axially by hand. You don't want a lot of play but there should be some
(.005 to .010) to allow for thermal expansion of the armature. If you can't, you have too many shims and/or misaligned bearings. Try moving the arm axially by grabbing the output shaft with a pair of pliers. If you get some play with this method, your axial shimming is OK and only the bearing alignment is bad. Either way, the only cure is to disassemble and reassemble correctly.

To check your com timing: You may first have to fix the axial play and bearing alignment problems to be able to do this test with any sort of repeatability. First remove your brushes. Next, while holding the motor in your left hand with the output shaft facing towards the right, spin
the arm. Now look at the com. A slot in the com should be exactly
centered on where the brush would be. This is 0 degrees of timing. If the slot is below where the brush would be; you have advanced timing.
If the slot is above where the brush would be you have negative timing.
Most motors shoot for about 5 degrees of advanced timing. This gives them an acceptable window during assembly of plus or minus 5 degrees which assures them of a finished product with timing somewhere between 0 and 10 degrees. By the way guys, this is the major variation in 'Stock'
motor performance and the reason that I buy five at a time.

If you feel that you have a good motor, one that you can easily move the arm and has somewhere between 0 and 10 degrees of timing, perform this final test. Run the motor on a power supply. At 4.00 volts your current draw should be below 0.75 amps. If not, you have one or more of the aforementioned problems.

Good Luck,
Bill

Jonny
2007.06.20, 04:33 PM
That's quite some information. I'd like to hear more from others who have these motors. Our club has just ordered 15 of these for next season.

Jonny

arch2b
2007.06.20, 05:25 PM
the spec motor was spec'ed basically from the atomic standard motor which several judges ran for review. the ONLY difference we asked for in assembly was the use of a ball bearing can and pre-installed leads.
with a couple exceptions (there are always some) everyone loved the atomic standard motor the spec motor was based on.

i am very disappointed to find there are quality issues with the spec motor we asked atomic for. due to the deadline for ordering these, testing them again before approval was not possible but in hindsight should have been done.

season 4 rankings are to have a column listing drivers motor choice ie, stock or spec.

we ran a practice race and an 8 minute heat with our spec motors and i don't recall them beign very hot, unless they were used in an awd. regardless this points to fluctuations in quality which again is disappointing to hear.

mk2kompressor
2007.06.21, 01:02 AM
on the back of jonny's post we will be using my muchmore motor tester to test and break in all 15 motors,do you want me to record and post the findings?
it will be current draw and rpm

arch2b
2007.06.21, 06:06 AM
please do. :)

pinwc4
2007.06.21, 12:09 PM
I broke in 12 of our 15 motors using the slave drive method. I then tested them at 4.8 volts with no load and got the following results

RPM Amps
37530 .91
37860 .83
37080 .78
35490 .68
37380 .94
36120 .72
37860 .77
35310 .73
34170 .69
36810 .91
36120 .92
39030 .87

One thing I noticed when breaking them in is that some motors took a lot longer to break in than others. Another member here mentioned that they were seeing variance in the brush tension which was leading to the different amp draws.

I only had 7 of these left so I checked the movement of the armature the remaining ones. 5 of them had plenty of play and moved smoothly axially within the can. 2 of them still had play but did not move as smoothly. All of them could be moved easily by my fingers and the ones that did not move smoothly did not correlate with higher amp draws.

I did not have time to use calipers to check the amount of play or look at the timing. Something as bad as 30 degrees would be obvious without having to take the motor apart unless there is a lot of binding.

This variance does not seem any different that the stock motors we were running. When I tested them if I remember correctly I got anywhere from 18000 to 25000 RPM.

Overall our club is excited about using these. I will try to give them a closer look this weekend.

arch2b
2007.06.21, 12:21 PM
thank you for the feedback. we naturally have to assume there will be some variation in the spec motors. these were not dyno'ed for tolerance testing and it's not unexpected to see some level of variation in performance. as pin has stated, there is an obvious variation among stock motors already, we could be seeing this same thing with the spec motor line.

i am still disappointed if anyone received an obviously defective motor however the label 'defective' can mean different things to different people. to me a defective motor is one that simply does not work and or causes some level of damage. if anyone feels they have a defective motor please submit a support ticket. i do not believe variations in performance within an accpetable range will consitute a defective motor however as this will be true for nearly every mass produced motor line.

rest assured the hfay judges are researching the issue and working to resolve any potential issues.

shuter
2007.07.10, 01:22 AM
Last week I installed 3010 fets and the new HFAY spec motor in two cars for club members. They ran very fast..... Uncontrollably fast for anyone in our club. (I thought this was supposed to be a stock class motor) Unfortunately, both cars are now dead. Won't know for sure until I get home and check them out but I am betting on fried fets. I have installed 3010 fets on a half dozen other cars running MR-02 motors and MA-010 motors without any fet frying problems. Anyone else frying fets with the new HFAY spec motor?

Fried fet issue aside. The new Kyosho stock fet standard is 3010s. When combined with the MA-010 motor the result is a fast, controllable, fet safe car with all Kyosho stock parts. If the HFAY goal is still to have a stock class, out of the box anyone can be competative racing format. This motor does not fit. It is anything but stock and requires an experienced racer to run.

imxlr8ed
2007.07.10, 02:44 AM
I broke in 12 of our 15 motors using the slave drive method. I then tested them at 4.8 volts with no load and got the following results

RPM Amps
37530 .91
37860 .83
37080 .78
35490 .68
37380 .94
36120 .72
37860 .77
35310 .73
34170 .69
36810 .91
36120 .92
39030 .87


What version motors did you receive (pinwc4)? It is said that the newer versions have vent holes in the can.

Also curious which ones you had these issues with Shuter...

Flashsp-2
2007.07.10, 03:31 AM
The variance in those motors is definitely within a reasonable amount. I did 8 identical pattern handwound motors and the variance was from 38,900-43000 RPM and the Amp draw was 0.89-1.12. Getting a large set of perfectly matched motors is very close to impossible, but the range that reported seems pretty solid for the most part.

shuter
2007.07.10, 08:29 AM
imxlr8ed - I am not sure about the vent holes. I'll have a good look when I get home in a few days.

arch2b
2007.07.10, 09:05 AM
shuter,
we have only 1 reported case of fried fets using this motor and it likely had more to do with the car do to mismatched fets.
while i'm sure it will happen, many clubs haev run these without this happening.

please continue to keep up updated. :)

pinwc4
2007.07.10, 10:42 AM
What version motors did you receive (pinwc4)? It is said that the newer versions have vent holes in the can.

Also curious which ones you had these issues with Shuter...

I do not remember seeing any vent holes on the motors I broke in. Is there a picture around showing the difference between the two?

Also I broke the motors in using a slave drive method at 2.4 volts for >2 hours. It took forever to get the brushes to seat on the batch I got. Not really a problem except I had volunteered to break in 12 of the motors for our club.

shuter
2007.07.10, 11:22 AM
shuter,
we have only 1 reported case of fried fets using this motor and it likely had more to do with the car do to mismatched fets.
while i'm sure it will happen, many clubs haev run these without this happening.

please continue to keep up updated. :)

The fets were newly installed 3010's. What do you mean by "mismatched fets" ???

arch2b
2007.07.10, 11:54 AM
The fets were newly installed 3010's. What do you mean by "mismatched fets" ???
he said he had both 3004 and 3010 fets on an awd.

if these were new installed fets you open it up to possibility of install issues as the potential source as well.

shuter
2007.07.12, 10:27 PM
[QUOTE=arch2b]he said he had both 3004 and 3010 fets on an awd.

I read early on that replacing the left or forward fet rather than doing them both was acceptable for stock motors. I did my first one that way and race it regularly with no problems. I run MA-010 motors in my MR-02's. Have things changed?


[QUOTE=arch2b]if these were new installed fets you open it up to possibility of install issues as the potential source as well.

As you know I am relatively new to fet replacements. Since my first failed attempt when I lifted a couple of pads I have had no failures on the half dozen 3010 fet replacements on my cars. It has been my understanding that where fets are concerned, if they work then the install is good. I guess nothing is that simple. I'll get a chance to look at them in about 10 days. If the fets are fried I will replace them and install MA-010 motors.

Appreciate the input and guidence.

arch2b
2007.07.13, 08:57 AM
i'm sure what you had in your awd worked for the absolute sotck level however any time you alter the fet arrangement you increase the risk. if we were discussing this about an mr-02 i think you would have less potetnial for failure however the awd came with paired 3010 and it really does use them with all the additional power the car has to produce. i would always advise against installing any fet that would reduce capacity no matter what channel it's servicing. that's just me though and fet experts can chime in on thier more intelligent review.

when your dealing with precision electronics, there is no such thing as 'if it works it's good'. it's more than possible for something to work adn not be working to it's maximum efficiency. again, the fet experts can chime in on with more intelligent review. my practical experience tells me though that any fet job has the potential atleast for some fault. i've seen plenty go up in smoke that took awhile to diagnose.

shuter
2007.07.14, 12:53 AM
While I do have a pair of AWD's I have not run them for about a year. All the fet jobs on my cars are on MR-02's. The cars I just converted from 3004 fets to 3010 fets for club members were also MR-02's.

mk2kompressor
2007.07.15, 07:48 AM
he said he had both 3004 and 3010 fets on an awd.

if these were new installed fets you open it up to possibility of install issues as the potential source as well.

i had a think about this and figured,electricity flows from - to +,if one fet is of lesser quality surely it will heat up and fail as it cant flow as much as its being fed by the other fet :confused:

imxlr8ed
2007.07.15, 03:40 PM
i had a think about this and figured,electricity flows from - to +,if one fet is of lesser quality surely it will heat up and fail as it cant flow as much as its being fed by the other fet :confused:

Actually, the forward "flow" is well compensated on the 3004 fet. (there's a difference in what the P & N channels can handle) It's actually more likely to go bad with the reverse function.