trunion turning set up

[Frank S]

While expanding the photos of my old eclectic computer screen background that I had made of some of my more memorable jobs and designs I stumbled on this one almost hidden like an Easter egg
It is a set up that I used to turn the trunions on a cannon that I was making for a reenactment drill team.
the set up required the use of 1 of my homemade steady rests a super spacer chucked at the bore end and a boring head with the cutter facing inwards on my 3 HP Bridgeport J head mill


the cannon bore was .300 wall 2" bore 4130 tubing embedded in the casting and it weighed around 300 pounds

[desbromilow]

Frank,

how was the bore tubing embedded in the casting?
cast in place, or pressed in later? (or glued in?)

if cast in, what was the process used to control shrinkage and assist in the alignment?


thanks,
Des

While expanding the photos of my old eclectic computer screen background that I had made of some of my more memorable jobs and designs I stumbled on this one almost hidden like an Easter egg
It is a set up that I used to turn the trunions on a cannon that I was making for a reenactment drill team.
the set up required the use of 1 of my homemade steady rests a super spacer chucked at the bore end and a boring head with the cutter facing inwards on my 3 HP Bridgeport J head mill


the cannon bore was .300 wall 2" bore 4130 tubing embedded in the casting and it weighed around 300 pounds

[Frank S]

Des, the bore was cast in place the pour was vertical muzzle up the mold was made of packed green sand around a wax model the wax was melted away.
the bore tube was 2.050" ID 3" OD 4130 with a half depth 2TPI left and right hand thread cut in the OD threaded on the butt end 3" deep @ 12 TPI then a flanged 3" long plug was made .030 over-sized the butt end of the tube was heated to 1000° for 20 minutes than the plug was screwed in place till it bottomed out and the flange was welded to the tube. A rig was built to lower guide and force if need be the tube in to the molten cast iron once the pour reached a few inches high the tube was lowered in place and held there though out the pour 2 large diameter sprews angling up from the trunions insured a complete fill of those once the pour was well past the trunions Sand plugs capped the sprew tubes it was 2 weeks after the pour was complete before the foundry got around to breaking open the mold mostly because they were busy doing their production pours.
Once I got the cannon barrel to my shop I turned ground sanded and polished the entire surface and ran a clean up home down the bore drilled the hole for the fuse and gave it to the customer to finish and mount in his cradle that he built I never got to see it fired but I had heard that their reenactments always ended with a big bang.

[desbromilow]

Thanks Frank... great to understand how it was done.

Des, the bore was cast in place the pour was vertical muzzle up the mold was made of packed green sand around a wax model the wax was melted away.
the bore tube was 2.050" ID 3" OD 4130 with a half depth 2TPI left and right hand thread cut in the OD threaded on the butt end 3" deep @ 12 TPI then a flanged 3" long plug was made .030 over-sized the butt end of the tube was heated to 1000° for 20 minutes than the plug was screwed in place till it bottomed out and the flange was welded to the tube. A rig was built to lower guide and force if need be the tube in to the molten cast iron once the pour reached a few inches high the tube was lowered in place and held there though out the pour 2 large diameter sprews angling up from the trunions insured a complete fill of those once the pour was well past the trunions Sand plugs capped the sprew tubes it was 2 weeks after the pour was complete before the foundry got around to breaking open the mold mostly because they were busy doing their production pours.
Once I got the cannon barrel to my shop I turned ground sanded and polished the entire surface and ran a clean up home down the bore drilled the hole for the fuse and gave it to the customer to finish and mount in his cradle that he built I never got to see it fired but I had heard that their reenactments always ended with a big bang.

[Frank S]

Des, On most of my builds both past and present. I tend to err (sometimes to the extreme) on the side of over explaining. I sometimes feel my dissertations may actually turn people off or prevent them from posting to a thread because they either are bored from my lengthy posts, or cannot think of anything to add or ask.
Among some of my favorite contributors here on these forums are in no particular order. Homemade Tools built by mklotz - HomemadeTools.net
Homemade Tools built by Captainleeward - HomemadeTools.net
Homemade Tools built by Paul Jones - HomemadeTools.net
Homemade Tools built by Rick Sparber - HomemadeTools.net
Homemade Tools built by jjr2001 - HomemadeTools.net
Homemade Tools built by rossbotics - HomemadeTools.net
Homemade Tools built by PJs - HomemadeTools.net
Homemade Tools built by Toolmaker51 - HomemadeTools.net
Homemade Tools built by thehomeengineer - HomemadeTools.net
Homemade Tools built by tonyfoale - HomemadeTools.net
I've been making things for going on 55 years pretty much all over the world but I have learned and many things from these guys I applaud their experiences and respect all of them. There are many more as well I just ran into a mental wall for their names

[NortonDommi]

Hi Frank S,
With regard to " I sometimes feel my dissertations may actually turn people off or prevent them from posting to a thread because they either are bored from my lengthy posts, or cannot think of anything to add or ask."
Your explanations are excellent and it is in the details that clarification of the process lies. Now come the next revolution or alien invasion I know how to build a better cannon.

[Frank S]

Thanks NortonDommi, you are another of the contributors who I follow with great interest
I don't know about a better cannon but it was very functional at 42 inches long with a 34 inch bore length 10" diameter at the butt and 8" diameter at the muzzle the 4130 tube made it much stronger than anything that could have been produced back in the day.
I would have loved to had been there the day they fired off a plastic sleeve filled with a 2 pound load of 3/4" ball bearings. at a guys barn from 150 ft. I was told it looked like the door had been hit by a mortar

[DIYer]

Thanks Frank S! We've added your Trunion Turning Setup to our Machining category,
as well as to your builder page: Frank S's Homemade Tools. Your receipt:

Trunion Turning Setup by Frank S

tags: machining

[Frank S]

I found a couple more pics of the cannon

[Paul Jones]

Frank S,

You never bore me with me with your "over explaining" the construction methods because I always learn something new and interesting from you. Your more than 55 years of experience is very welcomed with me and thank you for all your postings.

Regards,
Paul Jones