131 replies to this topic

[havlicek]

Dang that's a great looking chassis Rick! It looks so...so..."automotive", no really!

-john

[dc-65x]

I used my Rick's jig to make up the drop arm.........



...........and install it in the chassis:



The chassis is all finished:









A few closeups:





Time to tear apart that old Pittman motor

[TSR]

Looks pretty so far. love the triangulation around the bracket...

[bosmeck]

a work of art brother!

amazing stuff

[tonyp]

The winner & Still Champion!

[dc-65x]

Thank you gentlemen . When three of the best think I'm on the right track, I'll forge onward for sure .

I tore my Pittman 6001 apart last night. I'll post pictures of the carnage tonight.

[dc-65x]

Time to tear apart my old vintage race motor. It still runs strong but it vibrates like crazy and the magnets are loose in the can. Here it bares its soul:



Mine is a later motor as it already has the hot armature (.4 ohms) shown in this ad:



Here's a comparison of my arm on the left with a new 6001X arm on the right:



Hey John Havlicek. This arms got an insullator in the middle of the stack :



I also want to fix the bone head move I did to melt the brush spring, plungers and mar this brush plate:



Next up it's "Mod City" for the old "Sellersville Slayer"

[Horsepower]

WHERE in God's name did you get that replacement arm? I've been trying to find one of those since time immemorial (whatever that is)! I didn't think they ever came out with it, even though the adds were in every magazine at the time. That IS the 6001X, right?
Oops, by the way, nice build! I've never had one (Pittcan) apart before.

[dc-65x]

Hi Gary,

I found this one on Ebay a few months ago. It's an early hot "competition" arm with the "X" designation in the part number. I've got another one in later packaging that's designated a "6 Volt". I'll show pictures of both and check out their ohm readings and eyeball their timing etc tonight.

[mdiv]

Lookin' great, Rick!

Mikey

[dc-65x]

Thanks Mikey

I dug up my other packaged 6001 armature. I thought since it was a "6 volt" it would be the newer bad a$$ replacement arm in the ad I posted. Wrong again . Check this thing out:



It's a double wind with the wires to the comm in sacrificial readiness to throw themselves to the magnet Gods without the competition models "retainer ring":



The timing is also reversed from the "competition armature"



The "competition arm" reads .4 ohms and the "6 volt" reads .6 ohm.

Gary,

Now I know why you've been looking for a "competition" style arm!

[havlicek]

Neat motor/arms Rick!

Hey John Havlicek. This arms got an insullator in the middle of the stack

Yeah I saw that and I'll tell you what, it defies logic to think that they simply did this to decrease the rotational mass of the arm as was suggested in another thread. Substituting one lam for a fiber insulator isn't going to change things significantly performance-wise. If they DID do it for that reason, then they were being silly and probably never tested it...OR they did test it and did it that way only because it was "percieved" to be lighter/faster by the "market" I tend to think that a company like Pittman whose stuff was solidly engineered had some other reason...but I guess anything's possible

-john

[Prof. Fate]

Hi

A few years ago, aftermarket group 10 "stock" arms came from a couple people with thin groove longetudinally down the stack purportedly for the same purpose. I don't say any of these assertians are true, just reporting what was said!

I agree, it doesn't make sense!

As we have both observed about these motors, lots of "improvements" have been done over the years and I haven't seen a decent way to test. It always devolves to the track.

fate

[tonyp]

John I bet it was something like the arm would not fit in a jig of some sort and a full lamination made it too long so they opted for a fiber.

In RC we leave spaces in the stack to get around the spec rules that called for a minimum amout of wire length for 27 turns. The wire had to be 62" and 27 turns so a short stack was out of the question. It makes a difference where the spaces are put in armature performance. The motors are way less eficient but put out a lot more watts and are faster which in spec racing is a big advantage.

We also made a blank with a slot down the center. The real reason was simply to make it easier to drill balance.

A lot of the 60's,"Technology" was hit and miss. People would try anything they could think of no mattery how crazy it was. A lot was simply a gimmick to make your stuff look different and trick.

[havlicek]

Hi Tony,

I hope you haven't lost your accent already...wear it loud and proud down there I bet you're right and that there's some mechanical (rather than performance) reason for the fiber in the stack.

A lot of the 60's,"Technology" was hit and miss. People would try anything they could think of no mattery how crazy it was. A lot was simply a gimmick to make your stuff look different and trick.

10-4, I miss those days

-john

[Horsepower]

This is STILL too much fun! This is one of the most "different" builds I've seen. Man, I love those old Pittman cans!

[dc-65x]

I'm having fun too Gary . I balanced the arm on my Tradeship static balancer. The heavy pole swung down so fast I couldn't believe it. No wonder the motor was buzzing like crazy when rev'd. Here's the finished arm:



Next I worked on the endbell. In lots of the old "Hop Up" articles in the period magazines they'd drill holes in things.....anything! If there was room for a hole, it got a hole . Not to be out done, I decided to put a "comm inspection hole" in my endbell.

I thought I show how and accurately located and sized hole is created with a milling machine. But first, a DISCLAIMER:

I know there are experienced hobbyist, machinists and tool and die makers (Hi Duffy ) looking in. This is just one method that works for me. And, yes, the part could have been held in the vise differently. But this was fast and easy. In my own shop I live a little more on the edge than I did when I machined for "the man". Double And yes, the darn adjustable parallel under the endbell is rusted.....crud . I cleaned and applied WD-40 after a chassis build but not good enough. I guess that's why Scotch Brite Pads were invented....but I digress.

So here is the endbell in the milling machine vise. The gizmo in front of it is an edge finder. It happily spins as you move the endbell closer and closer......



.........and when the bottom part jumps off center you've located the edge of the part:



Then the milling machines adjustable dials are turned the correct distance to locate the hole from the edge you just "edge found". With the endbell located exactly where the hole should go a pilot hole is drilled with a stiff special purpose drill called a center drill:



A pilot hole helps keep the standard drill from wandering off center:



Drills often don't leave that nice a finish on the sides of the hole. I finished this one off with and end mill. Since the end mill cuts on the sides too it acts like a boring operation and insures the hole will be on center even if the drill (which just cuts on its tip) did somehow wander off:



Finally a countersink makes a an nice deep chamfer to make the hole purdy:



The finished hole......hey what's that nut doing in there



I drilled out the brass rivet that held the brush plate on so I could flip it over and hide the burn marks my bone head move put in it. Here are all the parts for the modified endbell:



I used a 2-56 flat head stainless steel screw, nut and some red thread locker to hole the brush plate on:



The finished endbell:



Time to epoxy the magnets into the can..........

Onward

[Jairus]

How fast do you wear out one of those Dremel wire brush wheels there Rick?


Just asking.... beautiful work! I have done the same thing regarding the brush holder. Sometimes replacing a broken one with screw... but I threaded the end bell, which eliminates the nut. But beautiful work!
(I need a mill!)

[dc-65x]

Hi Jairus,

I love Dremel wire wheels .

If the hole in the endbell wasn't already so big I'd have just tapped the thing. But, I'd have to use a No.4 screw and it was SO big looking I went with a smaller No.2 screw and a nut.

Yes, you do need a mill .

[Jairus]

Crazy idea.... but why did you not flip the endbell over and drill and tap the other side? Then you could have milled that first side with the "comm view" hole?

[dc-65x]

Jairus, that's not a crazy idea at all. I'd have to drill another hole for the motor bracket but that's no big deal. I'd have to counter sink the other end bell mounting hole too. It's already been "screwed", so to speak, with a self taping scrrew but may be able to accept a counter sunk No. 2 machine screw. Without checking it might work. Doing this would have eleminated using a nut which would be more elegant. I like elegant . Sharing information is a good thing thanks

Onward

[Duffy]

I know there are experienced hobbyist, machinists and tool and die makers (Hi Duffy ) looking in.

(Hi yerself Rick )

We "Experienced" toolish guys have a wise old saying: "What Works, Works."

Duffy

[havlicek]

I balanced the arm on my Tradeship static balancer. The heavy pole swung down so fast I couldn't believe it.

Hey Rick,

Did you check the shaft for runout? Usually when an arm is that far out, it's the shaft. The most significant part of the weight equation is the stuff farthest from the axis of rotation (shaft), like the actual laminations and the magnet wire. If the winding is pretty close to the same length on each pole, the lams use usually pretty close on their own since they're just stamped metal. Another VERY cool project!

-john

[dc-65x]

Hey Duffy, I might get mine built before you

John,

I put the arm in a 3/32 collet in my Sherline lathe and ran it slowly. There is a slight run out. I slid the arm in and out of the collet and ran it at different positions. The run out appeared the same. It almost looked as if the shaft was straight but the laminations were running out . I put the thing together and it does run much smoother than it did before balancing.

Anyway, here it is going together. Epoxy everywhere! Just like making a mud pie when you were a kid:



Here it's all cleaned up. I removed the ball bearing shields so I could flush them out. I didn't have a jig motor to build the chassis with. The motor got covered with acid flux and I had to scrub it with soap and water. I think it looks cooler now too:





The finished motor:



Here's the bottom showing the flat bottom screw that replaced the sheet metal screw that hung down 1/16":



I modified a Simco brush spring to fit to give it a try:



I broke it in at 6V for 20 minutes and it draws about .7 amps.

Time to put the whole thing together

[havlicek]

It almost looked as if the shaft was straight but the laminations were running out

Wow...could it be that the lams were formed a little off with one side being larger and they assembled them all with that side on the same pole? Anyway, static balancing can make up for some of that and it sounds like the Tradeship balancer does a fine job. The motor looks sweet as heck too, typical "Thigpen Bulletproof"!

-john