13 replies to this topic

[anumber1]

I bought five PS 4002fk motors about two months ago. So far, the three I have tried are two tenths off pace compared to 4002FKs that I fielded from last season (last seasons motors all have at least two or more races on them).
 
Break in has been performed in the same manner on all (1/2 hr on a power supply at 4v).
 
Banging my head on the walls trying to figure out why I am so far off pace, I put a used, year old motor in my car and although not blistering fast, got that .2 back in the same car compared to my new this year motors.
 
I know, yes, I know... Tis a thing in sealed, cheap motors that they are not all gonna be bullets. However, another racer (and friend that shares info) has also found that the motors he purchased recently are also two tenths off like my motors.
 
Has something changed with the Pro Slot 4002FK that I am not aware of? Just dumb luck? 
 
Throwing down $75 on disposable motors and not finding a one that will be competitive is really frustrating!
 
Any tips? All advice welcome!
 
Al

[The Number of]

Nothing to do with luck, the last batch that started about three months ago have all been what you found – about .2 off the ones we got last year. Tried everything to make them faster, no luck.

[anumber1]

Well... At least I'm not nuts.
 
Tried new springs (Champion lights) and different brushes (Golddust and BF2s). Didn't help a bit.
 
I performed an autopsy on an old motor and a slow but low miles new one. 
 
The mags in a new one gauss at about 70% of the strength of a well-worn old one that threw a wind after five races. 
 
Are the magnets in these things ceramic? Might a zap help? I only have access to a standard ceramic magnet zapper.

[The Number of]

Tried all the springs and brushes too with the same results. Zapper for ceramics won't work; they are something different.

[Samiam]

Mags are Poly-Neos.

 

You will need to consult the "Master Blaster" Ken- H! He states that he has mastered the zapping of these polymer neos. He has a special "rectified" magnet zapper hooked up to his blow hole. He'll eat beans for a week then "Turbo-Blast" away. 

 

Seriously,

 

These are cheap motors that have gone off the low end cliff of quality control.

 

De-wind an arm. Maybe they decided to add 10 or 20 winds.  

[anumber1]

Yeah. I get the fact this is typical QC for things of this nature...

Lack of competitive motors is killing my season though. Gotta run 'em and the new dogs are indistinguishable from the older, faster ones.

[MarkH]

It is the "Triangle of Truth" as with all products. Each point of the triangle has a different value for manufacture process: Time, Quality, and Cost. You can only have two and the two we get is Time and Cost.These are most likely made as fast and as cheap as possible.

 

I just bought three of these. The right bush hoods were junk pointing up about 10 degrees on each. I tried to straighten them and two broke at the bend. The motor that did straighten seemed OK until I put it on the power supply. It would not turn over even at 12v. Spun it with my fingers and finally started running. Vibrated like crazy. Then I moved the good hoods to another motor. It too need help to run. I cut the trailing edge of the brushes down to see if that would help. It would now start on its own. Seemed pretty smooth at first but started to act stupid and quit running. One of the poles on the comm was burned up. I am guessing brush bounce, maybe??

 

So I guess I will just buy some quality arms to put in these and use them for play motors.

 

This topic has been beaten to death here for all these cheap motors. No need to do it again.

[Samiam]

Bring them back to the track and demand your money back. Pro Slot will make good if they are defective.

 

Personally, I would like to see us go back to built motors with tagged arms. Spec out a set up and pick an arm. Lots of orgs already run C-Cans with Contender/Challenger arms. I would spec a can with a connection between the vent hole. No delicate light weight set ups that bend every time you wreck hard. Cans like Mura,Champion,RJR, and Pro Slot that hold up better than the thin ones from Koford or Kelly,

 

Or just run JK Hawk Retros.

[Fast Freddie]

Three out of the last four I bought this year sounded bad and would not gain RPM. They felt out of balance but once I took a closer look I realized the arm was riding hard against the can bushing. The magnets were set too far down in the can. 

So I removed the seals and took them apart. In the process the endbell bushing nearly fell out. I removed the magnets that were retained by a glue more like clear RTV then Super Glue. I repositioned the magnets so the tips were parallel and the brushes would ride in the center of the comm and used Super Glue to retain them. I shimmed the arm correctly, epoxied in the endbell bushing and soldered in the can bushing, aligned the brush hoods, and set the spring tension equally. 

They now run as smooth as silk and RPMs are no problem. They weren't out of balance, just out of spec. The problem is without seals I can only practice with them. Unless you catch a few good ones like I have from last year this is what needs to be done to get your money's worth, or just buy another 100 and hope you get some good ones.

[Guy Spaulding]

30 min at 4v break-in? Did you pull a brush to see if it was broken in after just 30 min? 

 

Straighten and align the brush hoods. Eyeball is better than nothing because the brush hoods can be so badly formed. The R-Geo alignment tool works great.

 

Then pre-arc the brushes in another motor or a turtle. Then do a water break-in in a white cup until the water turns gray. Then 30 min dry at 4v. Then remove the brushes and narrow them to reduce comm overlap (or just trim the tips off).

 

Then you might consider zapping the magnets. Neo magnets are actually too strong and cause magnet/arm lock and a ceramic zapper can actually soften them. (Just be sure you zap them the same direction. Zap them backwards and you might have to throw it away)

 

Then run the piss out of the motor. Heat-cycle over and over so the edges of the comm segments burn, and the segments become narrower. 

 

Have you ever noticed an FK motor runs faster the older it gets? (To a point...)

[MSwiss]

We've had mixed results with these at Chicagoland.

Most problems seem to be with heavier, Hardbody cars.

Ones with uncut/stock brushes, frequently need push starts, on both tracks, but mostly on the Fiedler Flat track.

I thought going from my puny 28A,12V power, to 200A, 13V, would help, but it really hasn't.

They also burn up pretty regularly on the King, on only 12.1V, but some guys really over-weight their cars (210+ grams).

With 60-75 gram wing cars, on 13.5V, we haven't had any failures, or possibly one.

In our monthly Retro (100-120 grams) fun races, again on 13.5V, zero failures.

That said, someone at a Retro race this weekend in Ohio said approx. 12 burned up, but IIRC they run on 14.2 or 14.3V.

PS: I forgot to add, on the last 18 I got in, the hoods look much better, and only 3-4 had sideplay/bearing alignment issues.

[John C Martin]

The ones at the championship race at whitehouse Tn. Last week Were fast about 400 were bought by Tracy ..
About 5 racers broke the old track record ..with handout motors..my only complaint with this motor is I wish the com was wrapped some are slinging the wire off at the tabs..
I broke the wire on one ( missing the move up ) and blowing the com apart testing another for the race ..I'll blame the last to cutting the endbell shaft off as this was allowed ..

[orangecrate]

I bought this proslot motor and reading about the problems the comm brushes in the hoods a lot of play and I removed the hoods the tooling being used to form the hoods are not machined properly and the hood metal is thin so care was taken in reforming to get as much play out and I had to enlarge the mounting holes  get as good of alignment  and this is not a rush job the metal can crack at the bends and if the rules allow can re-solder using very thin solder and flux and a low wattage soldering iron.

In my point of view this motor, poor materials, machining, etc Proslot correct the problems and may cost a little bit more instead of buying a bunch of them and get  a lemon

[Robert BG]

I hate to say it because I've run Proslot for years and they were good to me before.But these are simply a cash cow for them.They know racers will buy them in droves and as long as they are selling and in the rules I see little being done about it.It's hard to qc thousands of things yourself and lets face it bad batches will come through.Having dealt with China before,it is very common for QC to go to h@*& after a few runs.I had to continually shop around and finally found a company in the states but even they had issues.Although I was able to deal with those personally

 

Hopefully they read these boards and lean on the suppliers some,although I'm sure they have already.