Anyone want to make a small part for my Shopsmith?

John51 · 11 May 2013

One part to be made and another to be bored/reamed.

It's the bolt and bracket that holds the non trunnion end of the Shopsmiths main table. There is slop between the bolt and the bracket which makes the table move under not much pressure. Until it's secured I dare not use it as a table saw, let alone with a dado blade or a molder head.

As you can see, the bracket is threaded which seems wrong to me, much less metal to hold the bolt and it has worn.

What I'd like is for the bracket to be bored/reamed just enough to get rid of the threads, then a new bolt made to give zero slop. The threaded end of the bolt needs to be the original size so as to screw into the main tables stanchion.

The 2nd pic shows the bolt partially unscrewed.

Being an American made machine it will require a non metric thread. (Are American threads the same as Imperial?)

Much gratitude and beer tokens if you can help me.

Myfordman · 11 May 2013

British and American threads are both specified in terms of inches and so are imperial but are different and not often interchangeable especially when a good fit is needed as in this case.

I've got some sizes of US threading kit and if the thread is one I have then I can make the parts.

Can you measure the diameter over the crests of the threads on the bolt and tell me the number of turns per inch on the thread please.

flh801978 · 12 May 2013

I can make you it if Myfordman can't

Ian

John51 · 12 May 2013

Thanks for the replies.

My £10 digital caliper says the threads are 0.495" and the unthreaded part is 0.490"

Threads aren't a full inch long so counting against half an inch on the ruler I got 7, meaning 14 tpi.

Myfordman · 12 May 2013

1/2" UNC which is a common US thread is 13 tpi so it sounds like an non standard thread unless you might of mis-counted?
Putting the end of a rule on a thread crest should align the 1/2" mark with a trough.

Anyway after some thought my favoured method would re-use the original screw so the thread details are now academic.

PM me if you want to take it further.

Myfordman · 15 May 2013

John, I got your first pm to which I replied but heard nothing further from you.

Do you still need help or are you sorted now?

John51 · 16 May 2013

Sorry about the delay Bob, life got in the way. I'm expecting a delivery so will be off to the post office as soon as he has been, hopefully less than an hour.