Help from rotary gods

[greenxman]

How anal does the tail stock have to be?

The stick will be cut up to make a small tomb stone.

Then 3 side of the parts can be machined.

My problem is getting the tail stock on center I am have a very hard time.

[crazy^millman]

Really easy process. Flip the tail stock over and make sure the face is flat to the table. Measure the center of the shaft sticking out as far as it can. Use the shaft to make sure the tail stock is straight along the X axis. Then from the center of the shaft to the center of the key slots on the bottom of the tail stock see what that is. They should be on center, but not always. Then measure from the center of the shaft to the face of the tail stock.  Now use that difference to machine slots on your keys plate you put on the table. Yes I assume you made keys on the plate you are mounting on the table since that would be what I consider the most logical way to make sure the plate you are putting the tail stock on will be where you expect it when removed and put back in place repeatedly. Now the plate you are putting your tail stock on is higher than you need so you can machine it down since it looks like from that picture the tail stock is lower than your 4th Axis. You will machine that plate down the difference needed from the center of the 4th axis to make up for the difference for the center of your tail stock. You will take your time cutting that face making sure you are within .0002" of the thickness needed. You will be using your .00005"  graduations .008" travel indicator with the correct doblocks stacked at the height you need broken down to .00005" accuracy. You will cut your slots only allowing .0005 max for the key slots to slip fit into. Now your plate can slide the length of the table. If you slot if not precise enough in the table to do that then you will machine that slot to keep .0002" tolerance down the length of the table you want to use your tailstock. Everything must be precise and when it is then you are golden for years to come doing what you need. I wouldn't use a aluminum plate for the tailstock I would consider A-2, O-1, 4140 H1050, or even 15-5 in H1050 condition, but you will figure that out after time.

[greenxman]

got a problem with that i can't reach the spacer plate. i would need 8 inch long tool holders. i can't even reach the table slots with a drill chuck and indicator.   

[jlw™]

You might as well give up then.  Just kidding, put the plate in a vice and mill to thickness then all you have to do is indicate.

 

I've done exactly what Ron mentioned hundreds of times.  Once you get the plate right indicating in takes all of 8 to 10 minutes and that's if you double check it.

 

Also, I'd like to add use anything but aluminum.  Especially if you intend to use the setup again.

[mikenaturalice]

The only thing I would add to what Ron said, I did a similar project and left a few thou clearance in the keys, since the machine key ways were not perfect. That way, if you have a very long piece, you have some room to indicate the tailstock perfect. The key is leaving just enough that it is easy to indicate perfect, but not so much you spend 20 minutes indicating it in. 

[htm01]

old machine we had like that we mounted a 4" plate to the whole table then we could machine with shorter holders and add whatever slots and holes we needed

[crazy^millman]

old machine we had like that we mounted a 4" plate to the whole table then we could machine with shorter holders and add whatever slots and holes we needed

 

Had to make some agitator hubs for the paper mill year ago. The hubs weighed 250lb starting and swung a 16" diameter across the largest points. The 4h Axis we had would only swing about 10" diameter parts. We made 6" riser for the 4th Axis that mounted the edge of the 4th Axis .1 in from the limits of the X travel. We then made the riser for the tailstock like what I mentioned above. We could machine anything we needed with no issues. On those hubs I would put Machinist Jacks under each index at a M00 to support the part, because the 4th Axis brake was not strong enough.

 

Funny I was doing High Speed Machining in 440 SS dry not even realizing I was dong it till now. Mazak had the spiral pocket routine like we have in pocket now. I would drill a hole in the center and then plunge a 3/4 endmill to depth and step it out using a constant spiral dry. I use to go through 10 1/2 endmills at $20 each to machine those hubs running them wet. Sales guy shows up with this new coating you run dry on SS. Endmill was $110 ea and money was tight. He said if it cannot do the job you don't pay for it. I was able to do 3 hubs with that one endmill. Nice eye opening experience back in the late 90's of what was coming to market with tooling.

[greenxman]

thank you for your input.

i can't raise the rotary head it is keyed to the table and weighs a lot ( i can't lift it i am just a little girly man )

there is not a lot of z travel ,plus mori seiki came in and installed it and set up the  control to tell the machine were the head is.

 

moving on

so the arbor i had turned all at once it runs out 1 tenth. prefect

i put it in the collet and it ran out. i thought i was helping by putting a stop in the collet and that made it worse.

took out the stop got the arbor to run with in .0005 with a little help from my friend (hammer)

indicated in the center to the arbor great!

 

now i went to A0 milled a rectangle and 5 boss on top for my part.great

rotate the head A90 indicate the arbor across the flats and on the boss the indicator does not move! prefect

rotate A270 check the other side it is out .005 yes five thousands. :wallbash:

the reason i went this way is there are over a thousand parts and wanted to do 5 at a time. the other big problem is the tolerance on the peaces

at this point i have wasted so much time it is costing a very big lose of money, and will have to pull the plug and get a different part in there to make some money.

i am not a stranger the rotary but this one got the best of me

i feel like i should go over to the production jobs running and just be an operator and tell that guy to go set it up.

[Guest]

I might be jumping ahead here but after you got the tailstock lined up and mounted your "tombstone" did you trim it in to be true?

 

When I have done what you're attempting, I rough out the shape but all final machining on the fixture is done with it in place.....you should then take out any runout.

providing your head and tailstock are lined up properly, you should be able to relocate that fixture is a follow on set up is needed.

 

Did this years ago, don't know how closely it fits with what you're doing

 

[Newbeeee™]

I may not be following here but...

With rotary on A0:-

If you touch the top of your fixture and zero the lever clock, then just move in X (ie run along the top) do you get 0?

Then without moving the A, position the lever clock on C/L against the fixture, and then move along the X (ie run along the side) do you get 0?

 

Then repeat for A90

Then repeat for A180

Then repeat for A270

 

Next put the lever clock on part of the fixture closed to your collet chuck and zero it.

Then rotate the A a full turn and see what the clock says.

 

Lastly, have you clocked the face of the rotary across the Y to see if the thing is square on the table, and also across the Z to see if it's say square.

 

This will give you an indication of your errors and where you need to look.

[Sticky]

It sounds like you have a few problems here:

 

1. It doesn't sound like you know how to find center of rotation of your rotary axis. This imperative before you can be successful with any of the other steps.

2. To align the tail stock to your rotary axis I would first recommend that you find the center of the tailstock in Z to verify it is accurate enough for your needs, if not you will need to make the appropriate spacer plate to fix that problem first and foremost. Then I would start working on getting the Y on center, and then start dialing in your X for parallelism.

3. Your issue regarding A270 being out .005" - it's hard to gather exactly what is going on because you haven't mentioned which surfaces you are dialing in on, and where they were made. If you can describe it better or include some pictures it would be easier to determine if it is a programming issue, center of rotation issue, or machine square issue. At the moment it sounds like a center of rotation issue (your fixture is not on center or the center of rotation value you are using is not accurate).

4. You don't mention how tight the tolerances are on your parts, but if you are +/-.0005 or less then you should set up offsets for each plane. This will allow you flexibility in adjusting you planes to get accurate parts, regardless of potential machine square, or fixture accuracy issues.

[greenxman]

it is fully machine in place after it is indicated in.

from one side the the other on the rotary face is .0008 over 7.25 inches

tomorrow i will have another guy double each it and let you know.

[Sticky]

You need to be more specific.

 

I don't know if this ".0008" of taper over 7.25" is in reference to your rotary face in relation to parallelism to Y, fixture taper in Z at A0, or taper when at A90 or A270 in relationship to parallelism in X.

 

What are you center of rotation values XYZ for your rotary, when you dialed in your tailstock, what were those values?

[greenxman]

sorry for the long reply thing got to crazy around the holiday.

 

the short of this is, we had to stop it was taking to long to figure out. did it in a vice and moved them around by hand. not the most efficient way but got it done.

 

the clock face is 200mm ( 7.8) that is what i indicated to be .0008 from on side to the other. and the center is not brand new. the collet chuck is new but did not feel right when you closed it.(returned it for another one still not here yet)

 

i can't raze the head with out major problems and cost. so that mean i can't reach the riser blocks regardless. can mill in place

 

i drew the position of all the components and unless they are with in 2 tenth it won't work. the tolerance of the parts is unforgiving one end will be good the other will be out.

 

the lesson for me is type of set up will not work in a machine with z travel limitation.

 

so the rotary head has to have the fixture or part only on the head may be a pillow block , but can't influence the block mounted to the face plate.

 

i have never bought a premade tombstone, i am assuming this is why they cost so much because of the accuracy. 

 

i thought i did a lot of home work guess not.this was a hard learning curve at to high of a cost.

[Sticky]

the clock face is 200mm ( 7.8) that is what i indicated to be .0008 from on side to the other. and the center is not brand new. the collet chuck is new but did not feel right when you closed it.(returned it for another one still not here yet)

 

For such a small distance there is no reason for that to be out more than .0001"

 

Even 1tenth over 8 inches is weak, a small flat surface should be easy to get in the 2micron or less range.

[taperlength]

Whenever I have to do something like that, I just make a different work offset for every position that we are machining at and then probe it at every position to set the work offsets.

 

I've done it with an indicator too, if the machine does not have a probe.

[greenxman]

yes the machine has no probe. the head is keyed to the table and mori's techs put it in i don't know what the install tolerance is? i would have to call the dealer.

 

we thought about separate offsets but there would be 12 and that would be tough for the operators we have to follow, in other words it would be more treble then it was worth and end up with junk and no time to remake them and xxxx my customer off on delivery.

 

things are getting slow so may be we can try it another way.

[Sticky]

It sounds like the real problem is your lack of experience with rotary machining.

 

Who cares that your rotary is keyed? Take the keys out and indicate it in properly.

 

Making multiple workoffsets is easier for the operators to follow, because it will read like a normal "3axis" program. If your operators are just button pushers and they don't actual watch the code or machine then it really doesn't matter at all anyways.

[Matthew Hajicek - Singularity]

Funny I was doing High Speed Machining in 440 SS dry not even realizing I was dong it till now. Mazak had the spiral pocket routine like we have in pocket now. I would drill a hole in the center and then plunge a 3/4 endmill to depth and step it out using a constant spiral dry. I use to go through 10 1/2 endmills at $20 each to machine those hubs running them wet. Sales guy shows up with this new coating you run dry on SS. Endmill was $110 ea and money was tight. He said if it cannot do the job you don't pay for it. I was able to do 3 hubs with that one endmill. Nice eye opening experience back in the late 90's of what was coming to market with tooling.

 

Ron,

 

  Which cutters and coating was that?

[crazy^millman]

Ron,

 

  Which cutters and coating was that?

 

Matt that was back in 98, but I believe they were made by Fullerton and it was the TiALn for the coating.  I want to think it was a 3 Flute tool also. 

[greenxman]

so sticky if i un- key the head are you going to pay for mori/seiki to come back are reload the perameters in the control for me? yes this control need to know were the head is.

[jlw™]

or you can look up the parameters in the manual and tweak it yourself if you're inclined to do such things.

[Sticky]

so sticky if i un- key the head are you going to pay for mori/seiki to come back are reload the perameters in the control for me? yes this control need to know were the head is.

 

No. This is basic stuff, you need to learn to do it yourself. Having Mori come out to dial in your 4th (including or not including storing the position in either the offset register, parameters, or variables) is a waste of resources.

[generaldisarray]

What is this machine model that needs to know where the un-trammed rotary is? Some kind of Next gen Maho/Mori?  Tool changer interference?

[greenxman]

(It sounds like the real problem is your lack of experience with rotary machining. )

 

 

the only lack of experience i would have is with a horizontal tombstone. this was what my original question was about.

 

we have 3 other 4th set up on different machine with no problems.

 

this rotary is new to this machine 2014 milltap 700 with a 840D seimens  that is password protected by dmg/mori. i guess i would have to ask the dealer if they would give me the code?

 

 

 

also i think this tread has bin beaten to death now. no use wasting anymore resources on it.