lining up holes on mill turn

[steveo25]

I was trying to get some ideas thrown around to effectively line up bolt holes in a cylindrical part on a Mori NL-3000Y mill turn with "Y" axis. The parts we are looking to do are approx. 3.0" in diameter and 20.0" long. They have through holes on each end of the pin going through the diameter approx. 7/8" from each face (2 holes). We have a steady rest and a stop tube for through jaw operations. What we have done in the past is face pin and drill the hole, then flip the pin and this is where we need to line up the hole that was done from the first side with the hole we will be putting in on the other side of the part. So we would line up the hole with a part on the jaw and once we figure out that angle we adjust the work offset accordingly for the "C" axis zero. Do you guys have any good ideas for positioning this hole quickly and so it will be spot on inline every time. Like I said it is just clearance for a bolt (we allow 0.0625" for bolt hole clearance)? I would love to be able to do both of these holes at the same time but with a 15.0" 3 jaw chuck we run into a lot of clearance issues. I attached a MCX file and if you run it through verify it will give a better explanation of what I am dealing with.

 

Thanks for any responses

N207V118.MCX-6

[crazy^millman]

Steve looking at your fiel give me no clear idea what you are doing. I would run it just like you have it though you say you cannot. Can you take a picture or something for someone to get a better idea what you are talking about. I would thinking looking at the wire frame you would just do one hole then use the transform rotate 180 degree and just run the hole at the cross locations if it is on center which is what it looks like. Unless I am missing something should be pretty straight forward.

[Pilot Plant Supervisor]

Soft jaws with a dowel pin slip fit so it can be inserted (and obviously pulled out before running) when the part is flipped?

[steveo25]

I was trying to get some ideas thrown around to effectively line up bolt holes in a cylindrical part on a Mori NL-3000Y mill turn with "Y" axis. The parts we are looking to do are approx. 3.0" in diameter and 20.0" long. They have through holes on each end of the pin going through the diameter approx. 7/8" from each face (2 holes). We have a steady rest and a stop tube for through jaw operations. What we have done in the past is face pin and drill the hole, then flip the pin and this is where we need to line up the hole that was done from the first side with the hole we will be putting in on the other side of the part. So we would line up the hole with a part on the jaw and once we figure out that angle we adjust the work offset accordingly for the "C" axis zero. Do you guys have any good ideas for positioning this hole quickly and so it will be spot on inline every time. Like I said it is just clearance for a bolt (we allow 0.0625" for bolt hole clearance)? I would love to be able to do both of these holes at the same time but with a 15.0" 3 jaw chuck we run into a lot of clearance issues. I attached a MCX file and if you run it through verify it will give a better explanation of what I am dealing with.

 

Thanks for any responses

 

I was trying to get some ideas of a good productive way to line up the holes down at the machine itself so we aren't stuck putting a guide pin and level to every part because we have so many of these parts

 

Soft jaws with a dowel pin slip fit so it can be inserted (and obviously pulled out before running) when the part is flipped?

 

This could work it might be something we will just have to try and see how it plays out. The only hard part would be making sure the dowel pin doesn't bind too much when clamping. If we bore our jaws at the top of the stroke and drill the hole perfect and have the location(back of the jaws) just right it might work out. We do have the tailstock coming up for support during the drilling so we would have to have some sort of location for the part(also overall length consistency).

 

Thanks for the responses so far

[within a thou]

We do have the tailstock coming up for support during the drilling so we would have to have some sort of location for the part(also overall length consistency).

 

Thanks for the responses so far

 

Make the pin long enough it rests up against the face of your chuck and it will bring your length in for you. Turn the part until the pin sits against the side of your #3 jaw and chuck face. Figure out the angle once set it and the next part just make sure that the pin is against your #3 jaw again and ya are good to go.

[steveo25]

We will try that on this next job and see how it measures out.

Thanks

[crazy^millman]

Again Steve, a picture of your setup would help me at least to see what you are trying to do. I am at a loss on why your machine like you have from your file will not do what you are after. Are the holes from a previous operation not shown on that file that you are trying to line up to? If you are not able to machine them in one operation which what I am trying to gather here then I have to assume you are doing one half of the part removing it from the chuck. Then flipping it around to do the other side and this is where the problem is coming from. If that is the case then none of the options listed above I think would work either. Can go off the 3rd Jaw since the part will be inside the chuck. Best bet might be to do the operation in a milling machine where you can do both holes at the same time through the part with the proper tooling or will have to make a timing fixture that comes from the back side of the machine has a way to engage the holes. Other than that you are pretty much stuck doing it the way you are currently doing it with what I can gather from your explanation.

[within a thou]

Ron,

 

How I understand it is that is the steady rest modelled not the jaws. The one end is held by the jaws and not down the spindle bore which is why he can use a level on the pin to pick up the first hole like he is doing right now. There is no turning of the OD. Just face the one end, drill the holes, chamfer then flip and repeat. He says he currently uses a level to align the first hole to the second.

 

It says the lathe is a Mori Seiki NL 2000SY which has a 2.5 spindle bore and this is a 3" bar.

[crazy^millman]

Okay then I was thrown off by the jaws in the file and not a steady rest. Well then sounds likes come off side of the jaw is the best bet. Lock the Chuck to a position like suggested, figure out the difference and go to town. Sorry I was being thrown off.

[within a thou]

Okay then I was thrown off by the jaws in the file and not a steady rest. Well then sounds likes come off side of the jaw is the best bet. Lock the Chuck to a position like suggested, figure out the difference and go to town. Sorry I was being thrown off.

 

Don't feel bad I had to reread it a few times myself lol thinking those were the jaws as well then I saw about the steady rest and thought about it.