An impromptu method of holding a thin part - water hatch flange for Bill Harris Steam Roller

comstock-friend · Aug 9, 2024

I'm building a Bill Harris Steam Roller based on the drawings in Live Steam Magazine. This started as a class CNC project at the local JC. As I spent my days engineering and doing CAD at work, I let the others do the CAD/CAM in class and I did most of the machine set up (Haas VF3) and button pushing. We made just about all the parts for a dozen rollers before the instructor retired and moved. The instructor and I hold most of the parts, plus we still have two other members interested. After about 15 years of inactivity, I decided I needed to get one running.

Getting down to the final details I needed to finish the water tank which has a water hatch. The Harris design has a plain tank lid with the hatch body soft soldered to top. I thought that was too plain so I drew up a flange to mount the hatch to. How to hold this 0.045" (1.1mm) thick by 1.75" (44mm) diameter flange? I knew I was using a Greenlee conduit punch to pop the hole in it. What If I used the punch to hold the flange for turning on the lathe and for holding in a vice for drilling the rivet holes? Well, it worked great.

Here's the punch body in a 5C collet for turning the sheared out blank.

On the mill to drill the holes. The body of the punch was centered using an indicator held on the spindle. My old Mitutoyo DRO doesn't do bolt circles, so I just used the offsets from a quicky CAD drawing.

After cleanup and soft soldering, I rivetted the flanged assembly to the water tank top. The top rivets are dummies, the top is held on by four round head 2-56 machine screws.

Last photo shows the tank top mounted to the tank body and sitting on the steam roller frame.

Now to schedule the boiler test at the local club (Los Angeles Live Steamers) and wrap up the final plumbing!

John

Charles Lamont · Aug 10, 2024

Nice job.

ChazzC · Aug 10, 2024

I agree – very nice work.

Could you give some additional details on the setup? From the first photo,

I understand holding the body of the punch in a collet (and then clamping the hex head in the milling vise to drill the bolt circle). Is the flange held in position because you didn't complete the punching of the center hole until after you turned the OD and drilled the bolt circle? If this were the case I would have expected to see a portion of the cutter profile on the outside face of the flange during the operations:

Thanks!

comstock-friend · Aug 10, 2024

ChazzC, exactly. The part is just started in the punch. It is deformed by the punch and holds very tightly. Don't look for the part to be completely flat, it did run out a bit. This isn't your method for high precision but in this case plenty accurate for what I was doing. The big help was in doing the bolt pattern. I guess I could have done it while the blank was still square (it never was square as I cut it out of the sheet with hand shears), but this worked out great for me.

John

ChazzC · Aug 10, 2024

Thanks for the confirmation, John. A very clever approach for a non-critical part: saved making a mandrel, and the part was already on/in the punch.

Charlie

the artfull-codger · Sep 5, 2024

comstock-friend said:
I'm building a Bill Harris Steam Roller based on the drawings in Live Steam Magazine. This started as a class CNC project at the local JC. As I spent my days engineering and doing CAD at work, I let the others do the CAD/CAM in class and I did most of the machine set up (Haas VF3) and button pushing. We made just about all the parts for a dozen rollers before the instructor retired and moved. The instructor and I hold most of the parts, plus we still have two other members interested. After about 15 years of inactivity, I decided I needed to get one running.

Getting down to the final details I needed to finish the water tank which has a water hatch. The Harris design has a plain tank lid with the hatch body soft soldered to top. I thought that was too plain so I drew up a flange to mount the hatch to. How to hold this 0.045" (1.1mm) thick by 1.75" (44mm) diameter flange? I knew I was using a Greenlee conduit punch to pop the hole in it. What If I used the punch to hold the flange for turning on the lathe and for holding in a vice for drilling the rivet holes? Well, it worked great.

Here's the punch body in a 5C collet for turning the sheared out blank.

View attachment 158904

On the mill to drill the holes. The body of the punch was centered using an indicator held on the spindle. My old Mitutoyo DRO doesn't do bolt circles, so I just used the offsets from a quicky CAD drawing.View attachment 158905 View attachment 158906

After cleanup and soft soldering, I rivetted the flanged assembly to the water tank top. The top rivets are dummies, the top is held on by four round head 2-56 machine screws.View attachment 158907

Last photo shows the tank top mounted to the tank body and sitting on the steam roller frame.View attachment 158908

Now to schedule the boiler test at the local club (Los Angeles Live Steamers) and wrap up the final plumbing!

John

Nice neat job