3/4-inch scale B&O P7d Cincinnatian

[Andy R]

I forgot to polish these before attaching the pins, so the polish is uneven.

[Andy R]

These were a bit of a fiddle to hold.
And I almost, almost forgot to make one left-hand and one right-hand.

These were only grooved on one side. I may make a new jig and groove the opposite side ... just because.

My old camera creates shadows where none appear when taking the pictures.

[Andy R]

I made these by silver-soldering 2 pieces together. The seam is visible.
I was hoping to reduce the amount of machining but instead created more work.

The Combination Lever, Part # 1128 is similar, and I will mill it out of solid instead of trying to repeat the silver-soldered rods shown above.

[Odyknuck]

Yep, amazing how much rework is the result of a minor mistake or accident. On the last wheel no doubt!

[Bill Shields]

Looks really nice.

FWIW

When you drill to pin the crank, be very careful.

Drills can follow existing holes..and small taper pin reamers may not.

I once broke a taper reamer in just such a situation ...the drill went in and thru the crank pin following the hole on the other side .. but not exactly up the center of the hole on the other side.

When I put the reamer in...it went snap because of side loading.

Granted that was 50 years ago....

[Harold_V]

Granted that was 50 years ago....

Doesn't matter. Hand reamers are still made from the same material and ground the same way. Those small ones are as brittle as glass. I also recommend AGAINST trying to use them under power, as they have a way of grabbing and breaking (voice of experience). Keep them well lubed and apply only light pressure as one turns in the proper direction. NEVER BACK UP A HAND REAMER. That typically leads to chipped cutting edges.

Yeah, I know you know these things, Bill, but the new guy in may not.

H

[Bill Shields]

I am pretty sure that I was driving the one that broke with a hand driven pin vise.

It really annoyed me because I was in the middle east at the time and had to ask one of my British coworkers to bring a new one back from the UK (weeks later). No internet ordering

Learned from the experience and still have the well used size 0000 replacement

[gwrdriver]

My understanding is that the two in Baltimore and DaveD’s are all from the same patterns, I believe made by Bruce Hamilton. I don’t know about any others. Also, I have no idea what became of the patterns.

Some years ago I had the opportunity to visit Bruce and see the two 7.5"ga Presidents and the workmanship was stunning. There was a 3/4" scale NYC Hudson (IIRC) in the same room which was equally stunning.

[Andy R]

IMG_4478s.jpg (115.51 KiB) Viewed 496 times

There were a lot of different setups to make these. I kept them together on the same chunk-o-steel until almost all operations were completed. That allowed easier handling and machining options. I will do that on other parts from now on (having previously made stuff to size first).

[Odyknuck]

Nice work Andy. Curious your radius rods are one piece. Mine are designed for 2 pieces as I believe to be able to assemble them on to the reverse link.

[Andy R]

Odyknuck,
I had not given a thought to making the radius rods in 2 pieces.
I followed Mr. Coventry's plans.
After reading your comment i examined the assembly drawing and do not discern any difficulty, so will be interested in your experience.
Regards,
Andy

[Odyknuck]

Thats good. I too made mine as the plans show. The plans may be duplicating the Prototype build. When I get that far I will be posting it on my build, so stay tuned lol.