Large work on a Bridgeport

[ttabbal]

I got a spacer for it. It fits great on the column, but the turret is a few thou too big. I was thinking of clamping it to the table and boring it out a little. I figured I should ask here in case I might have missed something and to get tips for the setup. I tried lining it up with the long bolts it came with and getting it as straight as possible. No dice. It's not off much, but I don't have a caliper or mic big enough to measure it properly. It's close enough I suspect I could pull it in with the bolts, but I would rather not have it press fit on there.

So I thought I'd clamp it down, or if it will fit, use the vise. Then use the Criterion boring head with a bar in the side mount. That would have a little over 6" from the spindle. Seems like a fair bit of stick out, but it is a light cut.

Another option is to use a rotary table. Mine is pretty small, 6" I believe. So I could mount a plate to it, clamp the spacer to the plate, and use a normal milling cutter on the ID.

My lathe is a PM1127, so I can't chuck it up on there..

 

[JimDawson]

Clamping it down to the table makes the most sense. The boring bar sounds good, but run slow. As I recall a BP is 80 RPM minimum unless you have a VFD. 80 RPM might be a bit fast at that diameter.

 

[benmychree]

With a carbide tool, 80 rpm should be OK for a light cut. Be nice if you could borrow a vernier caliper to check the sizes.

 

[ttabbal]

I do have a VFD. Not sure how low it can go. I have insert boring bars. I'll probably need them as I don't think my cobalt bars are long enough to reach. I plan to run slow, both for SFPM and vibration. I've never done anything quite like this, so it should be interesting.

 

[ttabbal]

After much cursing at my garbage indicol clone, I have it centered. I could probably give it a go if I owned a left hand boring bar. *facepalm*

Maybe if I bore up?

It looks a bit high on the pucker factor to have that bar acting like a propeller, but it feels sturdy when the boring head locks are set.

 

[DavidR8]

Yikes!
Hitting to go button on setup would be terrifying!


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[ttabbal]

Yeah. I kind of like the idea of going from the bottom. The spinny bits will be enclosed in cast iron when starting up!

 

[westerner]

I am a complete beginner, when it comes to machining. I am NOT a complete beginner when it comes to breaking tools or machinery.
That pic scares the crap outta me.

 

[ttabbal]

It feels like a bit much. I'm not sure what would be better though. I haven't fired it up, still thinking about options.

 

[DavidR8]

Yeah. I kind of like the idea of going from the bottom. The spinny bits will be enclosed in cast iron when starting up!

Making note of the machinist term “spinny bits”


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