Dan Mosley
Member
- Messages
- 1,169
- Location
- Palm Springs, Ca
Tom...........see the pictures below - I "did not" weld the coupling on the D-arm for a good reason. What I found was that a 1" round cold rolled would slip into the 1 1/4 square perfectly and smoothly. So I made the coupling so I can remove it for 1" Hollowing bars and then if I want to use 3/4" hollowing bars I slip the coupling into the 1 1/4 square D-arm and secure it with the 2 set bolts.....The coupling then is a 1" round with a 3/4" hole bored all the way thru.
How I made the coupling was I took a pc of 1" round cold rolled steel that was 4 1/2" long down to a local welding shop and had them drill a 3/4" hole 1/2 way thru it.......but I found after getting it home that this was not the best idea for 2 reasons: Why 4 1/2" long ? No reason really just a guess....
1). A drill press for drilling something like this you will get some travel in the drilling - not a big deal and I can compensate for it easy enough but i also realized
2). That if I would have had it bored all the way thru I could make longer boring bars and they would slid thru the coupler and into the D-arm and actually extend all the way back as far as I would want it to go. I would not have to be accurate or limited by length of the boring bar at all.
A lady at work who's husband owns a machine shop took the same 4 1/2" pc and made it so a 3/4" bar would slip in and out smoothly all the way thru (I assume he did it on a metal lathe)......In exchange I gave her a few vessles because he wouldn't take any money for doing it - told me it was no big deal to bore it out and I was right not to use a drill press.....I already had the holes tapped and my angle grinder did the flat spot on it you see in the picture - easy enough.........I used 1/4" tap and SS small bolts...
Actually, there are alot of times I do not have to use both set screws (bolts or whatever) when i put it together to hold it secure but, I was not sure at the time I fabricated it so I made it super strong.......welds and brazing a bit sloppy but its built strong everywhere
If you go to a steel shop to buy your steel - you can do what I did - I grabbed a pc of 1" round and walked around putting it in and out of square tube steel until I found a wall thickness that creates a nice smooth slide when you put the 1" in to it.............worked out perfetly.......
Anything else.......let me know.....making it was alot of fun and I did change my mind on things thru the process
How I made the coupling was I took a pc of 1" round cold rolled steel that was 4 1/2" long down to a local welding shop and had them drill a 3/4" hole 1/2 way thru it.......but I found after getting it home that this was not the best idea for 2 reasons: Why 4 1/2" long ? No reason really just a guess....
1). A drill press for drilling something like this you will get some travel in the drilling - not a big deal and I can compensate for it easy enough but i also realized
2). That if I would have had it bored all the way thru I could make longer boring bars and they would slid thru the coupler and into the D-arm and actually extend all the way back as far as I would want it to go. I would not have to be accurate or limited by length of the boring bar at all.
A lady at work who's husband owns a machine shop took the same 4 1/2" pc and made it so a 3/4" bar would slip in and out smoothly all the way thru (I assume he did it on a metal lathe)......In exchange I gave her a few vessles because he wouldn't take any money for doing it - told me it was no big deal to bore it out and I was right not to use a drill press.....I already had the holes tapped and my angle grinder did the flat spot on it you see in the picture - easy enough.........I used 1/4" tap and SS small bolts...
Actually, there are alot of times I do not have to use both set screws (bolts or whatever) when i put it together to hold it secure but, I was not sure at the time I fabricated it so I made it super strong.......welds and brazing a bit sloppy but its built strong everywhere
If you go to a steel shop to buy your steel - you can do what I did - I grabbed a pc of 1" round and walked around putting it in and out of square tube steel until I found a wall thickness that creates a nice smooth slide when you put the 1" in to it.............worked out perfetly.......
Anything else.......let me know.....making it was alot of fun and I did change my mind on things thru the process
Attachments
Last edited: