Bi-Polar

[De Bruin]

Your welcome Dan, I thrive on hitting the "stacks" or the inter-web for that kind of minutia.

.....any progress with the new locale for the Atlanta club?

We're at least better organized with the two local clubs now merged, membership up to 19 which is double from last year and having a well-led and organized search committee; but it's been a slog with 9 months of searches, vetting, walk-throughs, offers etc.
Some personal politics as you'd expect too in that some will only accept locales close to their homes, others object to the more affordable properties due to the perceived security issues in a given area. so I'm leaving it up to the rest of the membership. Wayne's club example of buying some land and building to suit has resonated though and gotten some traction, but that's problematic too as well for reasons that would make for some pretty obvious if not dry reading hence my " thread drift" here's otherwise complete.

[Retroniac1]

Bob,
I have been out of the country and just catching up. I may have some or all the parts that you need for the second Bipolar except the pantographs. I can take a look this evening.

BTW this is great work. Like you I am also fascinated by the MR electrics, particularly the Bipolar.
Rob

[bob turner]

Thanks. No need, though - I made an aluminum plate in about 30 minutes of effort, and it snaps on perfectly.

I am all out of large pantographs, so may capture a pair of Lionel GG1 pans - they are widely available. I have the 2-rail unit standing , and will temporarily install smaller pans and do a photo shoot.

[bob turner]

Here they are - the one on the left is 2-rail, but not yet operational. I think I have maybe $170 invested, having lucked out with Perry's Hobbies on a set of cab castings about two years ago and a mechanism last month. Patience is a virtue.

I note that both are sitting a little unevenly - ever try to get 28 wheels on the track all at the same time, while the wheels you have been successful with are quite jealous that maybe some other wheels will make the grade?

And those small pantographs! They just won't do. But I am patient.

[Retroniac1]

Bob,
It looks great. Patience has always been a valuable trait, especially in O scale.When will you start the other.
Rob

[R.K. Maroon]

Bob, those do look good. I thought I was following along, but somehow I missed the fact that you had two of these. If you get a chance, would you take individual shots, post them, and identify the manufacturer? As far as I know, NJ Custom Brass did the only bipolar in brass, while the Lionel and MTH versions are both cast (but maybe I am wrong?). Further, the Custom Brass and MTH models are the "pre-rebuild" version, while the Lionel model is the "after rebuild" version, which is notable for its rounded nose.

Here is the Custom Brass version:

https://www.dropbox.com/scl/fi/647gf9zawy6v3ywa4y33d/Custom-Brass-Bi-Polar-As-Delivered-Paint-01.JPG?rlkey=xuq4qkecl6dv518f8fc9ts11l&dl=0

The MTH version can be seen here:
https://mthtrains.com/premier/spotlight/04_2019/f

And the Lionel here:
https://www.trainz.com/products/lionel-6-18389-milwaukee-road-bipolar-electric-e-1

[bob turner]

Both of mine are the MTH versions. The reason I have two is because I got pieces from Perry at a favorable price, and in between an entire unit from retroniac for a very favorable price.

I will 2-rail the one on the right in the future, but I think I shall subcontract for steel driver tires and machine a new mandrel for better concentricity - the current 2-rail wheels have ever so slight eccentricity, and while they will track ok, there may be some extra wobble (probably not unlike the real thing).

[bob turner]

Well, welcome back, and thanks to our hosts for continuing MTJ.

My brother Mike is going to ask for a quote for a hundred Bi-Polar driver tires - anybody have a copy of the RP-25 O Scale wheel contour drawing?

I want to get Bob Stevenson involved, since he has moved to the North Carolina area and has experience in this sort of thing - but we are still in the early planning stage.

Edit: a very quick google search got me the official NMRA drawing. It may wind up too expensive, but with CNC or the modern equivalent, it might not be - if we do it, I was thinking of .180 overall disc width (as opposed to the standard .172) but for marketability in other applications the 172 standard might be better.

I have run .145 and .115, and am of the opinion that for my tracklaying skills, .155 is rock-bottom minimum. Sunset apparently agreed with me in the 1990s.

[bob turner]

My brother came through - he apparently has friends in the computer-controlled machining community. I offered to pay, but he made them a gift.

I have finished the first half with new steel driver tires. We "specced" them at .180 wide, but they came .170 - close enough.

I bit the bullet and made a new mandrel to fit my 3/4" collet, thus guaranteeing concentricity, and sharpened my cutting tools so I could machine the MTH steel tires without loosening them from the Zamac castings. I have finished the first half-locomotive, and will test it this evening.

I forget the exact trajectory, but I think I bought some shells from Perry (eBay hobby shop), and then some trucks without motors. Then Dr. Retroniac sold me a complete unit at a very favorable price. Finally someone had a fifth "half-locomotive" truck set on eBay, and I snapped it up. So now I have the brass-tired unit (with very small pantographs), an extra half-truck assembly with steel tires, and I am about to attack the trucks under the pristine unit.

I figured it would take a week to do the tires on a half-truck, but I had them done in two days. For the insulated wheels, I just used plain old paper (it comes in various thicknesses - envelopes seem a couple thou thicker than the notes within - and JB Weld as the adhesive - I now coat both sides of the paper, then slide the tire into position, using a gauge to get everything on. I leave a little wheel casting inboard of the insulated tire, so I do not have to worry about shorts against the truck block.

I would get another photo or so, but these new trucks look pretty much like the ones I did six months ago. Tread diameter is slightly less.
I currently have two projects that will slow this down - a really cut-up 2-10-2 and a badly assembled FA - but after that I intend to get one of these giant units rolling under its own power. I am insulating so that I will have to have a "tender" - not unusual for me, and really simplifies the insulation problems. I have a Milwaukee express refrigerator car that will do just fine.

[bob turner]

I now have two mechanisms (chassis? Engines? Anybody know electric nomenclature?) running on tracks. Tonight I will wire them up and put the die cast body castings back on. Too bad I didn't spring for Scott's Olympian Hiawatha cars!

[bob turner]

Body castings are on, and temporary wiring has enabled me to pull a short freight train. When running this thing is smooth as glass, but I am having some derailment problems on curves. It may be due to the center idler drivers, which run in a slot. I am thinking of either springing them or maybe just putting a brass snubber above them so they cannot bounce upward.

I did a short video, but have no idea how to get it in here - maybe Shutterfly can host it.

Edit: Nope - Shutterfly won't accept videos. You will have to use your imagination.

[R.K. Maroon]

Here is a video of the first run of Bob's Bi-Polar:

https://dl.dropbox.com/scl/fi/zkp4wfktdtcyh84ghfb0f/Bob-Turner-BiPolar-First-Run.mp4?rlkey=dl4rjq5285m818l1ys7q2jena

These things are hard not to like -- all those driving wheels! You can see why Baldwin would think the Centipede idea was a good one.

Jim

[bob turner]

I now have two of them running on 2-rail track. I have learned a couple tricks along the way. I already knew about sharp lathe tools and concentric mandrels, and now I have learned that the dummy driver on the inboard side that rides in a little slot needs to be blocked from above so it cannot move more than a few thousandths above the powered drivers.

I have also learned that any MTH motor will do (since one of my mechanisms came without motors) but you need to carefully grind the end of the worm so it does not contact the bottom of the worm gear cavity. Today I found that to be true of the motors designed for the Bi-Polar truck as well. It could be that MTH figured the worm would carve a little cavity in the bottom to aid in keeping the worm shaft vertical, but if so, that is a poor design. Trim a couple thou off with a sanding disc, then polish with a whetstone. Wrap the motor in a rag with tape to avoid any magnetic dust getting into the magnet area.

I chose to insulate one side completely, and to pick up current from a "tender" (in this case that ancient Ambroid express car). That really avoids complications. I do that on Train Masters and six axle Alcos as well, when going 2-rail, although normally I avoid anything plastic. The Train Masters were just too good to pass up, at a hundred bucks each, and K-Line actually gave me one free. I used the very first NWSL conversion set on that one, and maybe four other similar kits for some Seacrest projects.

Off to the airport. Today is tame, just a couple Stearman flights and a beer at the end.

[Retroniac1]

Bob,
The wiring arrangement is so simple and reliable. Thank you for keeping your eye on the prize with the Bipolar project. This is all very good info.
Rob