New Sherline lathe! I'm ecstatic!

[kweierbach]

I'd put that mill to work and make a block to mount on the cross slide with a hole the size of the shank on your drill's that is on centerline with the chuck to hold your drills and use the z axis feed to drill the hole.

[MechanoMan]

Originally Posted by kweierbach I'd put that mill to work and make a block to mount on the cross slide with a hole the size of the shank on your drill's that is on centerline with the chuck to hold your drills and use the z axis feed to drill the hole.

Well that's certainly a top idea there.

My concern with that would be in keeping the bit's axis totally parallel with the bed and ensuring that the crossslide position has it pointing straight down the rotational axis. Probably not insurmountable problems, there will need to be some careful setup procedures though. Bolting 4 T-nuts into the crossslide rails does not provide a high degree of rotational accuracy, maybe I'd make a mount with tight-fitting rails sticking out underneath it to position it accurately on the crossslide.

I'm just surprised I seem to be the first person to want to bore a deep hole automatically? I didn't see any tailstock-crossslide mounting hardware or instructions on this operation.

[Teyber12]

With my x3 i often just bore a hole with nothing there before with a boring bar in polyethylene, gotta take it slow then slowly work to the ID i need. If your machine seems up to the task doesn't hurt to try but it makes a ton of racket and is scary on the x3, can't imagine it on a sherline lol

[kweierbach]

Originally Posted by MechanoMan Well that's certainly a top idea there. My concern with that would be in keeping the bit's axis totally parallel with the bed and ensuring that the crossslide position has it pointing straight down the rotational axis. Probably not insurmountable problems, there will need to be some careful setup procedures though. Bolting 4 T-nuts into the crossslide rails does not provide a high degree of rotational accuracy, maybe I'd make a mount with tight-fitting rails sticking out underneath it to position it accurately on the crossslide. I'm just surprised I seem to be the first person to want to bore a deep hole automatically? I didn't see any tailstock-crossslide mounting hardware or instructions on this operation.

Turning the O.D. maybe more of problem. what kind of turning tool did you get with this lathe. you may get chatter when turning that thin of a wall if you don't have postive rake turning tool.You may want to turn it first using the center for support then drill it and hope that the steady rest doesn't mark it up to much.Or drill it first and if the center is to small you will have to make an end plate and tighten the against it for support.

[Thayer]

I don't have a lot of experience in this regard, but what about just mounting a block on the cross slide and drilling it on the lathe? If you don't move the cross slide, you could then reverse the bit, secure it in the block (slotted with a clamping screw?) and drill away?

Thayer

Originally Posted by MechanoMan Well that's certainly a top idea there. My concern with that would be in keeping the bit's axis totally parallel with the bed and ensuring that the crossslide position has it pointing straight down the rotational axis. Probably not insurmountable problems, there will need to be some careful setup procedures though. Bolting 4 T-nuts into the cross slide rails does not provide a high degree of rotational accuracy, maybe I'd make a mount with tight-fitting rails sticking out underneath it to position it accurately on the crossslide. I'm just surprised I seem to be the first person to want to bore a deep hole automatically? I didn't see any tailstock-crossslide mounting hardware or instructions on this operation.

[imserv]

Originally Posted by MechanoMan Well that's certainly a top idea there. My concern with that would be in keeping the bit's axis totally parallel with the bed and ensuring that the crossslide position has it pointing straight down the rotational axis.

You can use the Z-axis ( Saddle) for drilling, if you mount a 3/8 shank drill in a 3/8 boring bar holder with a Quick Change tool holder.

You will have to indicate the QC post in, and will probably want to use a piece of 3/8 drill rod or Dowel to check the axial alignment of the 3/8 tool holder. Mount a mag base indicator to the chuck, and rotate the chuck to indicate the rod into the center of rotation and also use the same setup to check along the length of the drill that the center of the drill is on center with the spindle. Check both top and side for alignment.

Fred Smith - IMService
http://www.imsrv.com

[MechanoMan]

I was able to accomplish the basics of what I needed by center drilling, then changing to the chucked twist drill and using the short thrust stroke of the tailstock screw, then just loosening the tailstock-to-rail screw and hand-ramming it into the Delrin, pulling out to clear, and repeating.

The trouble I have now is parting. I have the 3.25" dia 4-jaw indy chuck (but it's not the official "Sherline lathe" 3.1"):

The problem here is that the only orientation which doesn't strike the bed is the jaws with the steps on the inside. This does not provide enough grip to stabilize the Delrin without a tailstock, not in this length. Tightening further only makes the Delrin pop out.

The problem in the parting is that you can't use a tailstock. Well, I tried anyways with the tailstock pressure minimal. Eh, the results didn't put me in fear of my life or anything. But even though the parting tool went in at 90 deg to the work, the tip walked WAY off to the right, leaving the left side concave and the right side convex when all was done. This happened irrespective of how fast it was driven in.

Why did the parting tool's tip walk so much? I see Sherline recommended a 5 deg angle on the blade when viewed from the top. I'm not sure I see why, that would seem to make it cut unevenly to me. I can't tell for sure what angle my blade does or does not have.

I kinda wanna just hold a hacksaw over it now and drop it down to cut it...

I found that with.... I guess it's about 3" long part with a 3/4" new diameter- the end face couldn't be finished either because again the jaws can't hold that stable without a tailstock, but the SteadyRest will probably cure that. In fact I might be able to use the SteadyRest instead of the tailstock for the parting operating, right? Still won't fix the real problem of the parting tool wandering though.

[kweierbach]

Originally Posted by MechanoMan I was able to accomplish the basics of what I needed by center drilling, then changing to the chucked twist drill and using the short thrust stroke of the tailstock screw, then just loosening the tailstock-to-rail screw and hand-ramming it into the Delrin, pulling out to clear, and repeating. The trouble I have now is parting. I have the 3.25" dia 4-jaw indy chuck (but it's not the official "Sherline lathe" 3.1"): The problem here is that the only orientation which doesn't strike the bed is the jaws with the steps on the inside. This does not provide enough grip to stabilize the Delrin without a tailstock, not in this length. Tightening further only makes the Delrin pop out. The problem in the parting is that you can't use a tailstock. Well, I tried anyways with the tailstock pressure minimal. Eh, the results didn't put me in fear of my life or anything. But even though the parting tool went in at 90 deg to the work, the tip walked WAY off to the right, leaving the left side concave and the right side convex when all was done. This happened irrespective of how fast it was driven in. Why did the parting tool's tip walk so much? I see Sherline recommended a 5 deg angle on the blade when viewed from the top. I'm not sure I see why, that would seem to make it cut unevenly to me. I can't tell for sure what angle my blade does or does not have. I kinda wanna just hold a hacksaw over it now and drop it down to cut it... I found that with.... I guess it's about 3" long part with a 3/4" new diameter- the end face couldn't be finished either because again the jaws can't hold that stable without a tailstock, but the SteadyRest will probably cure that. In fact I might be able to use the SteadyRest instead of the tailstock for the parting operating, right? Still won't fix the real problem of the parting tool wandering though.

I would shorten up the parting tool blade to just enough to part off the part.
you may have to use the steadyrest to support the part when you are machining it. you may want to try only drilling and machining enough for one part at a time keeping the rough stock solid for better support.
Kevin