The Home Machinist!

I like your fixture for turning the radius on the rod ends. Faster than a rotary table.

Harlock wrote: ↑Sun Sep 30, 2018 12:31 pm I like your fixture for turning the radius on the rod ends. Faster than a rotary table.

True, that, but with risks. Unless stops are set, it's very easy to undercut, and if one attempts to climb mill, things can get interesting very quickly.

H

Harold_V wrote: ↑Sun Sep 30, 2018 3:55 pm

Harlock wrote: ↑Sun Sep 30, 2018 12:31 pm I like your fixture for turning the radius on the rod ends. Faster than a rotary table.

True, that, but with risks. Unless stops are set, it's very easy to undercut, and if one attempts to climb mill, things can get interesting very quickly.

H

I can't take credit for that fixture, it is John Bailie's. He has been using this method for cutting a radius for many years on multiple projects. To the best of my knowledge, he has never had a problem.

Climb milling the finish cut makes for a beautiful finish, but you've got to keep the locks tensioned up and feed carefully, or do it on a CNC:)
When you were milling the radius on the rod end, was that sitting on a pin or bolted from the other side? Clamped down(can't see the whole part)?
I'd be afraid the mill would suck the part up off the pin....

Good to see the kids so involved at their age:)

rkcarguy wrote: ↑Mon Oct 01, 2018 11:13 am Climb milling the finish cut makes for a beautiful finish, but you've got to keep the locks tensioned up and feed carefully, or do it on a CNC:)
When you were milling the radius on the rod end, was that sitting on a pin or bolted from the other side? Clamped down(can't see the whole part)?
I'd be afraid the mill would suck the part up off the pin....

Good to see the kids so involved at their age:)

I don't have CNC equipment, nor does John. I can't speak to milling the radius, because I didn't do the milling on the rods, John did. However, I've seen him employ this method on previous projects. The part isn't clamped down - the end being milled sits on the pin, and John holds the other end of the part in his hand to rotate the work against the end mill. He sent me this photo to show some other parts made by hand rotating. John included the following commentary with the photo of his work "The pivot must be held so it cannot slip sideways. I use an old vise jaw with a vee groove. Use small diameter cutters. Only climb mill on the last pass. Make sure your health insurance is paid up and have 911 on speed dial. "

I used a similar set up, except:
The pin in the vice was theaded for a bolt that held a brass washer on top to secure the part from coming off the pin.
I could tighten the bolt/washer to add some drag to the rod, for finer control.
The results are satisfactory.
~RN

Donhost4449 wrote: ↑Mon Oct 01, 2018 11:16 pm

rkcarguy wrote: ↑Mon Oct 01, 2018 11:13 am Climb milling the finish cut makes for a beautiful finish, but you've got to keep the locks tensioned up and feed carefully, or do it on a CNC:)
When you were milling the radius on the rod end, was that sitting on a pin or bolted from the other side? Clamped down(can't see the whole part)?
I'd be afraid the mill would suck the part up off the pin....

Good to see the kids so involved at their age:)

I don't have CNC equipment, nor does John. I can't speak to milling the radius, because I didn't do the milling on the rods, John did. However, I've seen him employ this method on previous projects. The part isn't clamped down - the end being milled sits on the pin, and John holds the other end of the part in his hand to rotate the work against the end mill. He sent me this photo to show some other parts made by hand rotating.
IMG_1362.JPG

John included the following commentary with the photo of his work "The pivot must be held so it cannot slip sideways. I use an old vise jaw with a vee groove. Use small diameter cutters. Only climb mill on the last pass. Make sure your health insurance is paid up and have 911 on speed dial. "

Scary! But it works and everyone can still count to 10 right?

Thanks for all the comments & encouragement. Yes, everyone can still count to 10! Moving on...

With my homework completed, I was back to John's shop for another day of fun. The boys had cut open the pedestals using our bandsaw at home, so now we needed to machine them to spec. We started with machining the font side (cylinder side) of each box. Plugs in the rods were used to measure the distance between the openings to make sure they were within .002" by way of feeler gauge inspection. Once the front side was done, we had a surface to measure off for machining the rear side (tender side) of each box. These were checked with both the rod plug/feeler gauge method, and with a telescoping gauge with micrometer. John's mill is just big enough that we were able to open all three boxes, both front & rear sides, all in one set-up. Next was the rod brass. John made a fixture to hold the bronze Oilite bushings in the lathe. A parting tool was used to cut the bearings to size. The bearings were pressed into the rod ends, and then reamed to size.

With the frames and rods done, it was time to put some parts together for a test fit. I had brought the wheel and axle sets that John and I made back in 2003-4. The bearing boxes were machined, but did require a little bit of file work to clean up. John is using the vise to hold a wheel set for filing. Next the frames went together using frame spaces that John had on hand from a old set of Chloe frames he had on hand. As things go, there was a slight bind in the motion. John is studying the rotation to discover the source of the bind. We ran out of time - I had to get back home for the boy's football game. John kept the chassis to study it and discover the source of the bind. I think before the kid's game was over, John had texted me with this video of the motion smoothly rotating. As it turned out, the rear axle quartering was off .009"


Next up we will take a look back to 2002 when this project got started, and what was completed before moving to Portland...

Where did you get those wheel castings? They look nice, and different.

Pontiacguy1 wrote: ↑Thu Oct 04, 2018 7:37 am Where did you get those wheel castings? They look nice, and different.

The wheels were cast at the Knight Foundry from patterns made by the late Don Juergenson for another build project about 25-30 years ago.

https://knightfoundry.com/

As promised, here are some pictures from the start of this project. John suggested I start with the boiler, because that is a part of a locomotive build that people sometimes get hung up on. I purchased the boiler tube on October 5th, 2002 for $30. All together I spend about $100 on materials for the boiler, and it took a little over one year to complete. John taught me to weld on this project - I had only done some limited welding during high school one semester in metals class.
The boiler was successfully hydro tested (300psi) on January 3, 2004 From there, we worked on the axle boxes, axles, eccentrics, drivers and crank pins. Unfortunately, I don't have many pictures from then.
Should anymore pictures from the start of this build surface, I will share at a later time. I thought I had some others, but this is what I could find.