Hot big block

[trickyvic3]

Monty,
Over the last few days I built up a 560 dia Parma rotor motor. I blueprinted everything from the endbell to the can bushing. I used new EXP magnets and matched a set that gaussed after zap @ 700 right on the button. I wound up with just a tad under a 580 hole when all was said and done. I used a new ps-706b 560 arm 38 degree . Did water break in for about 1min and followed up with naptha drip on the com. @3volts the amp draw was over 4.0 at first, after a few seconds of running, it settled down to 3.8 and stayed there. The motor runs great but seems to run hot. I thought at first that maybe I had to arm spaced just a little to tight, so I pulled the arm and removed 1 07 spacer and replaced it with an 03. This gave me a little more play, but it still seems to run a little hot. Any ideas??
Oh, and the brushes are gold dust,and look to be seated well around the com. Champ light springs.

PS- You,ll be happy to know that my next build features a BOW 560 arm !!

Vic

[MantaRay]

Vic, check and see if the brushes are a little to long........make sure the long leg of the spring is not touching the edge of the brush......happy building..

[trickyvic3]

Thanks Ray I,ll check that out.

Vic

[trickyvic3]

I just double checked the brushes and springs, and everything looks good. It almost acts like the gap is to tight, but I had around a 578-580 hole so with the 560 arm that should be a good gap. That would give me about a .010 air gap. One mistake I may have made was not remeasuring the hole with the endbell mounted, but the endbell fit nice and tight so I dont think that would have closed the hole up that much if at all. It runs fantastic , but after a few minutes at 4volts it gets hot. Not to the point that its going to fry, but hotter than it should for that short amount of time.

Vic

[PitStopGuys]

Try a different set of brushes.

[trickyvic3]

Thanks Pete,
Do you think I may have a bad set? I used brand new gold dust brushes, but I guess I could have a bad set. Is there any way to test brushes prior to installing them?
You know its funny, I was talking with Scott at PCH yesterday, and he said something about a bad batch of Gold Dust brushes, but I thought he was kidding. Maybe he wasnt !!! It really pi#### me off when you put so much time into something, but I guess thats all part of motor building.
Thanks for the help.

Vic

[BillyBob]

he said something about a bad batch of Gold Dust brushes, but I thought he was kidding.
Vic

On one of the Drag Boards they are all raising sand about the bad batch of Gold Dust. Like a whole bulk pack. That's 50 pair of junk. Ouch. Try you a set of Big Feets and see it that will fix the problem.

[SteveDee]

While I have used Gold Dust, I have always preferred the Big foot. This goes back for years,

[Phil I.]

VIC,
You started with a 38 DEG arm. Did you advance the endbell more? Most of my 40 DEG + arms run good but hot. I use a fan between heats.

OLPHRT
PHIL I.

[[email protected].]

Vic,

There's hot, and then there is TOO hot. If this is your first adventure with something drawing 4 amps, you may be just experiencing a normal phenomenon. Also, remember that these things cool by convection, the air that blows through. Thats why my final bench test is at 6 volts, not three. Just like gearing on the track is best set so the motor really revs high, its good to rev fairly well on the bench.

NOW, ABOUT THE BRUSHES - ALL OF YOU GUYS PAY ATTENTION!!!

Yes, I have reports of troublesome brushes, from a few sources I trust, and will name. But first, the generalities: the reports are for both makes of 'premium' brushes, and the problem was rapid wear in the water, not excess heat. Both builders contacted the manufacturing seller, and got unsatisfactory answers.

First up was Lou Pirro, who had just cracked open a new bulk pack of BIGFOOT II brushes. A fair number were wearing in water like they were Chinese cheapies. He had called Koford before me, and was told it just couldn't happen. I replied that it was new to me, seeing as how the only way I'll use BFII brushes is at knifepoint. Sorry Steve, I have opinions too, and I'll stand on my record. Lots of big race wins, never on any brush but Golddust.

Well, just as I put the phone down, feeling smug about urging Lou to switch brand of brush, I opened my inbox to a message from Paul Wilde, making an identical observation about a new bulk pack of Golddust! I replied that I had just heard the same story about the BFII, and I was starting to suspect there might be some truth to my old suspicion that they are all made in the same factory. I do believe the is some difference in the composition, however.

Paul followed up with his answer from ProSlot: Dan reccommended that he limit his breakin time to much shorter intervals. Now that really addresses the problem...not!

With considerable trepidation, I tore into my own new bulk pack, but so far, no problems. Maybe I'm just lucky?

The last time significant numbers of brushes were bad, the problem was hard or dirty spots in the material, and it affected about 20% of them. This all seems to me to be entirely different. If anyone else has direct experiences, not just repeating the rumors, I want to hear about it!

[trickyvic3]

Thanks Monty I feel a little better I think lol. I,ve been breaking them in at 3volts in water for about 45 seconds to 1 min. The a few drops of naptha on the com, and running for a couple of minutes. But I,ve only been using 3-4 volts. So after the water break in I should crank up the volts to 6 ?? or just go with 6 all the way through?
Well anyway, heres what I tried this afternoon. I thought maybe the brushes wernt broken in quite enough, so I did another water dip for about 30 sec. Blew it out good, oiled it up, and a couple of naptha drops again. It seems a little better, but still got heated up after a couple of minutes. I think maybe your right !! Im just not used to the bigger amp draw or the 560 arms for that matter. I would have tried a different set of brushes as Pete sugested, but I didnt have another set on hand. Besides Im cheep !! lol Now after talking with you guys I think its probley normal heat because it seems to run just fine.
Vic

[trickyvic3]

VIC,
You started with a 38 DEG arm. Did you advance the endbell more? Most of my 40 DEG + arms run good but hot. I use a fan between heats.

OLPHRT
PHIL I.
Phil,
Ive got the endbell set pretty straight on it, so it should be right around 38 give or take. I think as Monty said Im just not used to the amps = heat yet. Most of the motors I,ve been building have been small arm motors with bigger gaps, so they dont really heat up. Im sure now that this motor is fine. Hey, you know what they say, If you cant take the heat, get out of the kitchen.lol
I aint gettin out of the kitchen !!! Hehehe !!

[trickyvic3]

Steve,
I have used the bigfoot many times in the past also, but after many hart 2 harts with Monty as well as a ton of other racers, I switched over to Gold Dust quite awhile back. Personaly? I think its a toss up. But you gotta admit, Monty knows his sh## so I go by what he suggest. He has'nt steered me wrong yet. lol

[[email protected].]

Vic,

You just brought up another good point. Do you own a timing guage yet? Is it a 38* arm because it looks like one, or because the package sez so? I have a pretty good eye for timing, but I see a lot of arms. Even then, arms with less familiar lamination profiles are harder for me to tell so I have to use a guage. Anyway, I've seen lots of supposed 38* arms that were as much as 45*. Knowing for sure will be important to know not so much to figure out how hot it should get in your hand, but how to gear it on the track.

Which reminds me also... when will you report on the test session?

[trickyvic3]

Vic,

You just brought up another good point. Do you own a timing guage yet? Is it a 38* arm because it looks like one, or because the package sez so? I have a pretty good eye for timing, but I see a lot of arms. Even then, arms with less familiar lamination profiles are harder for me to tell so I have to use a guage. Anyway, I've seen lots of supposed 38* arms that were as much as 45*. Knowing for sure will be important to know not so much to figure out how hot it should get in your hand, but how to gear it on the track.

Which reminds me also... when will you report on the test session?

Monty,
Yes I do have a timing guage, Just dont know how to set it up !! lol At some point soon, I,ve got to get Bill to show me how to set it up and use it.
Ok Monty, Im going to show my age now,,, what test session ?? Did I forget something we had talked about? Doesnt supprise me. lol
Vic

[[email protected].]

Well Vic,

Most folks build a motor and just can't wait to put it in a car and test it. Me, I build a motor, drop it in the mail, and the recipient just can't wait to put it in a car and test it. If you share a build with us here, we are interested in what parts you used and how you did it, but most of us just can't wait for YOU to put it in a car and test it.

In other words, we wanna know ifn' its fast!

[trickyvic3]

Well Vic,

Most folks build a motor and just can't wait to put it in a car and test it. Me, I build a motor, drop it in the mail, and the recipient just can't wait to put it in a car and test it. If you share a build with us here, we are interested in what parts you used and how you did it, but most of us just can't wait for YOU to put it in a car and test it.

In other words, we wanna know ifn' its fast!

Hahaha !! Ok Monty, I get the point. Well for what its worth, I have built and sold a few over the last couple of months. Most are small arm 16-Ds. I know your not crazy about small arm 16s, but I have quite a few new arms that I had picked up over time and figuerd I might as well cut my teeth with them. So far I,ve gotten some good feedback. I sold a blueprinted stock 16-d 2 weeks ago, and the buyer e-mailed me this morning and told me he won his first flexi race with it last night !! Man,, thats a great feeling !! Kinda makes it all worth wild. I,ve also build a couple of so-so motors, but I guess thats all part of the game. My goal is to use nothing but high quality in every aspect of building. I still have a ways to go, but I also understand that you learn by doing, and try to learn from your mistakes. One thing I can tell you for sure is, Im hooked , and I am having so much fun learning and building. One question I have for you though is what size drill bit do you use for drilling and tapng the endbells? I bought an 0.80 tap but cant seem to find the right size bit. I know this sounds like a no brainer, but I cant seem to find an 0.80 bit.

Vic

[[email protected].]

Vic,

The tap/drill info is easy enough - but I gotta question using 0-80 machine screws in plastic endbells. 0-80 is standard operating procedure in aluminum, but the threads don't hold up well in glass filled nylon, too fine. I, and most everyone else I know, use 0-48 self tapping screws for the can/endbell interface, and while ProSlot supplies a #5 torx head modified 0-80 screw in the # 643 endbell kit, I don't use them.

Use a 1/16 drill for #0 thru holes, and 3/64 for 0-80 tapped holes. These are hardware store or machine shop supply items. Don't bother at hobby shops or even most raceways (although a smart raceway operator should stock this stuff, along with hood tools, airgap slugs, brush hones etc. If I had a raceway again, I would!). Sources like Enco, MSC, or even Micro-Mark can deliver taps, drills, reamers, needle files, countersinks, tap handles, rubber abrasive products, dremel friendly diamond bits, calipers, micrometers, etc. right to your door. Just try to order this stuff in reasonable batches, or the shipping/handeling will cost more than the tools & supplies!

I'm surprised you don't test drive these motors youself. The entire state of New Hampshire would fit inside the county I reside in, so I don't want to hear that Need for Speed is too far away to visit on some regular basis!

[trickyvic3]

Monty,
Thanks for the tips. No, Need For Speed is not far from us at all. 25mi or so. The trouble is just being able to leave the house long enough. Joes been in bed all winter, and hasnt really been healthy enough to get him up there. Now that the good weather is comming, I hope to start getting him up and back out some. Oh by the way, you were right once again about that big arm motor. I took it back out to the shop today, hooked it up to the power supply at 6volts and let it run for a few minutes. At the higher rpm it did run a little cooler.

Vic

[TRM124]

Monty,
T/R Motorplex had the Drag racing Nationals last week. They had problems with the Gold Dust & BFII's. Rick said they were both wearing out too quickly during the "Water Break in". He discontinued selling the brushes he had, and contacted both Dan & Stu. Bad news for the drag racers.

Ted Melton

[PitStopGuys]

I hate to be a smart-***, but if they're wearing too fast during water break-in maybe you should just cut the time you're running them in water. Rapid wear is a BIG problem circuit racing. That I understand. Not being a drag guy I don't have a feel for brush wear in that type of action.

[trickyvic3]

I was talking with Ralph at Need For Speed today, and he was telling me that they use big foots and only run them in under water for about 10-15 sec. He told me they have had no problems what so ever.

Pete
Have you guys been having trouble with gold dust brushes wearing down to quick? or any other problems with them?

[mudd75]

There are some production brushes that look very simillar to premuim brushes and they wear out really quick Any chances of a wrong label?

[trickyvic3]

I suppose its possable, but if you look very closely you can tell the fakes from the real deal.

[Bill from NH]

I forget which is which, but the PS production brushes are a different color than their aftermarket Gold Dusts. If I recall correctly, the aftermarket ones are lighter & more bronze in color.

[trickyvic3]

I forget which is which, but the PS production brushes are a different color than their aftermarket Gold Dusts. If I recall correctly, the aftermarket ones are lighter & more bronze in color.

Yes they are bill. I remember Monty teaching me that way back. It still can be hard to tell though, if you dont have a real set to judge the difference. And, if the so called real set you have are fakes, guess what? lol Then your in big trouble !! Hahaha

[Phil I.]

:mad::mad:

They are called "Gold Dust Pro" motor brushes. P.N. PS901 at $3.50 a pair. Unless you have a TRU Gold Dust to compare with. They are hard to tell the difference. If they 'go away' in 25 seconds in a water break in. They are not " Pro" Gold Dust. The ones that come in the PS 4002 are not the PRO brushes as they go away too fast..As do the stock Parma...In a water breakin..:)

OLPHRT
PHIL I.

[mudd75]

Stock parma's turn your water into soup in no time!!