25 replies to this topic

[B.C.]

Was on the online auction site earlier and saw Revtech arms for sale.
 
I have heard of these arms, but not sure who did the winding and what decade. Were they sold new in the '70s or '80s or ?
 
They are C-can open arms. Thanks for any help.

[tonyp]

Revtech was Neil Mccurdy. Not sure when they were wound but I think '80s.

[MSwiss]

I would guess late '70s, maybe '80 or '81.

When I got back in, in late '81, C-cans were on their way out for G27 and G7.Most guys were going to peanut motors.

I would only hear the occasional reference to Revtech.

I think he had moved on to doing R/C stuff by then.

[tonyp]

Probably right. They went into R/C and later on Trinity purchased the company and Neil came to work for us.

[MSwiss]

Neil eventually moved to Chicago to work for Bosch.

I talked to him once or twice, on the phone, when he called Stu, inquiring about purchasing a few industrial motor prototypes.

I'm kind of surprised he never wandered into any Chicago area raceways.

I may have heard he is now retired.

[tonyp]

I'm sure he is retired. I know he was losing his eyesight due to diabetes.

[Pablo]

"The online auction site"? Where, exactly, please? Can you be more specific?

[Phil Hackett]

I don't recall Neal winding armatures but "Big Jim" Greenemeyer worked with him for a while, say 1975-76 and Big Jim wound and produced armatures. Maybe Jim marketed them through RevTech. I don't recall. Bob Green also wound arms for Neal.

All of this was in the '70s. By 1982 or so Neal had given up slots for R/C and moved Revtech to Bakersfield(!!!) sometime after.
 
Tony P.: Neal is retired.

[idare2bdul]

Neal and his original partner Jeff Gilbert both wound arms. Greenamyer came on board shortly after they had bought Checkpoint if my memory is correct. Foamy (AKA Dennis Hill) also wound armatures as well as making the Revtech Iso chassis. I joined Team Revtech in 1977 as a semi-pro and eventually ran in R/C for both Revtech and Checkpoint. Other people sometimes wound a few arms; Foamy could probably name a few.

Neal and Jeff were both working at Panavision when I joined the team. Neal was their chief engineer as I remember and did significant work developing the Panaflex camera that became the industry standard.

Revtech when it was in Chatsworth was like a slot car version of a country club. Unbelievable stereo system and a Sony Betamax that seemed to magically get movies before they came out. A Foosball table was also there as a distraction.  
 
There aren't many happy endings here, Jim and Jeff are both dead and Neal is in very ill health. This is the part of growing old I really hate, losing friends sucks. We recently lost Chuck Crawford another Team Revtech RC racer.

[B.C.]

Thanks to all for the great information. Growing older unfortunately means losing those that helped build the hobby/sport that we, if there is still a place to race, can still enjoy today.

Not only are we losing friends but we are losing places to race.

[Phil Hackett]

Revtech when it was in Chatsworth was like a slot car version of a country club. Unbelievable stereo system and a Sony Betamax that seemed to magically get movies before they came out.

 
The Nakamichi stereo system was very, very good! I was also impressed with the hundreds of (cough... cough... I'm old!) vinyl albums Neal had lined up ready to play...

[Foamy]

In the couple years I was there, I did the finish work on the arms. I couldn't get the winding down to look pretty.

 

Chassis building, motor setup building also.

[Phil Donaldson]

Hey Brian,
 
I had a Revtech motor that I bought from Speed & Sport back about '76 or so.It was a 26 single and was a very high quality piece.

I have a Revtech 25 single still in the package.

[havlicek]

From what I can make out, that's a nice looking arm! #25 wire on a maybe .500" stack with a big honkin' Kirkwood-type com and one little pinprick hole on the visible pole = stump-pulling torque, brush-eating revs, and a lovely smooth whistle.

[Phil Hackett]

Mura blanks always were the easiest to balance and they kept their balance. Plus the shafts were extremely straight and round. That armature was most likely a .510". I don't remember .500" diameter arms becoming common until the early '80s.

[havlicek]

That armature was most likely a .510". I don't remember .500" diameter arms becoming common until the early '80s. 

 
Yes of course, and these routinely finished at or around .510". I was referring to the stack length.   
 

Mura blanks always were the easiest to balance and they kept their balance.

 
They often had large amounts of material removed with those wide/shallow angle bits they used, so I don't know that they were any easier to balance than any other blank, but if they "kept their balance", that might be because the lams had wide legs, a really large "hub" section that's actually a diagonal between poles, and a very thick crown. With any decent lamination, the consistency of the winding and the shaft are probably both as important as the lam itself as these all play a part in balancing.  

 

Actually, if you spin Mura lams on a common center (the shaft), you might be surprised to find that they aren't particularly concentric. The Mura .007" lams did produce some great-running motors, but the great winders and how they were finished (welding, tying, balancing, grinding, etc.) played a big part in all that.

[Phil Hackett]

For all those reasons.

[havlicek]

??? I listed reasons why they don't seem to balance any easier at all, but might "stay balanced," even though that's kind of a difficult thing to quantify for any armature.  

 

I've seen it said that an armature's balance can change if the coils shift/move under rotation, but that wouldn't have anything to do with the laminations. Also, laminations with a thin crown (especially .007" lams) are said to sometimes deflect outwards and even hit the magnets in a tight setup, but again, that wouldn't have an effect so much on balance as on the destruction of the motor.

 

It seems that how absolutely concentric the lams are, could certainly affect how easily an arm made from those lams can be balanced, but the Mura lams don't seem to be any more concentric than the average, and I've looked at them an awful lot.  

Mura .007" lams were used a lot, maybe because they were more available than other .007" thick lams?... beats me.

[MrWeiler]

Neal McCurdy passed today.

[Jesse Gonzales]

Back in 1971, probably an August USRA race I was looking at Jeff Gilbert's car and noticed that there was hysol showing between the coils so I remarked "whaddaya" got on there like 15 turns? he said 15 turns of 25. Most of the other guys and myself were putting on like 19 or 20 turns of 25 with about 20 to 21 deg timing, Jeff had his cranked way over which helped generate a wild wail up near S&S bank. At the time Jeff was part of J&M (Jeff & Monty) and had not yet joined up with others.

 

Jess Gonzales

[idare2bdul]

Revtech and Checkpoint arms after they purchased Checkpoint, had various production methods that could affect balance. Many of these were connected to the epoxy process. At some point a bell jar was used to suck down the epoxy with a vacuum. Spinning the arm to get excess epoxy off the armature. Baking the arms for different times and temps. Different epoxies were tried and some made it to production. It was pretty common for armatures to get run once and get hot enough where the epoxy and the wires they secured were then stable for the rest of the armatures life. So run em, rebalance and then it was usually not required to rebalance just retrue the arm. An autoclave would have been useful.

 

Big Jim made limited runs using what he called X Epoxy that he thought gave better high temp protection. I don't recall if those were team arms or went out to customers. 

While experimentation went on and team members at times ran one off's to find out if they worked. It was not unusual for an armature that had a blemish or minor defect to be used as a team arm because we wouldn't sell a rough looking arm.

 

I ran an experimental 25 1/2 on a short stack that had been considered a failed experiment at Rosecrans. It had a very distinctive whistle and because of weight, gearing or both I could punch both banks. This was a full sized C can but the move to smaller and lighter motors began in earnest soon after. I think If I had a do over I would have frozen the technology with C cans and the polymer Cobalt X magnets.

[Jesse Gonzales]

I had quit racing before the Steube's sold checkpoint and never met the "big Jim" fellow but I know that Jeff Gilbert was baking his epoxy black, probably an effort to raise the Tg (the temp where it starts to get gummy). I don't think there was sml that was coated with black insulation back in those days so it had to have been hyper-cured to black. 25 1/2 wire did exist though, I had/have a roll that Essex gave me for free as it was an odd size. I had very good luck with those arms, they actually ran like a full 25 but seemed livelier on orange tracks.

 

I never tried short stacks as I had considerable influence from Bill Ussery and also Bob Green towards long stack arms but then we were working on short underpowered track solutions.

 

Jess Gonzales

[Phil Hackett]

Revtech and Checkpoint arms after they purchased Checkpoint, had various production methods that could affect balance. Many of these were connected to the epoxy process. At some point a bell jar was used to suck down the epoxy with a vacuum. Spinning the arm to get excess epoxy off the armature. Baking the arms for different times and temps. Different epoxies were tried and some made it to production. It was pretty common for armatures to get run once and get hot enough where the epoxy and the wires they secured were then stable for the rest of the armatures life. So run em, rebalance and then it was usually not required to rebalance just retrue the arm. An autoclave would have been useful.

 

Big Jim made limited runs using what he called X Epoxy that he thought gave better high temp protection. I don't recall if those were team arms or went out to customers. 

While experimentation went on and team members at times ran one off's to find out if they worked. It was not unusual for an armature that had a blemish or minor defect to be used as a team arm because we wouldn't sell a rough looking arm.

 

I ran an experimental 25 1/2 on a short stack that had been considered a failed experiment at Rosecrans. It had a very distinctive whistle and because of weight, gearing or both I could punch both banks. This was a full sized C can but the move to smaller and lighter motors began in earnest soon after. I think If I had a do over I would have frozen the technology with C cans and the polymer Cobalt X magnets.

 

Perhaps the most "famous", or better, infamous "Cyclops" armature Jim sold (a one-off... it was a production mistake). It was an armature where there was an air bubble in the epoxy and the baking caused a hole in the epoxy. It turned out to be a missile....

[Jesse Gonzales]

Phil, was Big Jim a "Mabuchi" winder or reverse "Mabuchi", they both have their strong points but most arms are wound in a standard Mabuchi style.

 

Jesse

[Phil Hackett]

Jesse, I can't answer your question: I don't know.