Wow. There is much to respond to and cover, here. In effort to cover similar sentiments, advice, and my retorts and queries there will be some rearrangement, so bear with me...
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwjJsO2B_6rOAhVs5YMKHSr0CY8QFggcMAA&url=http%3A%2F%2Ftotallyscrewedmachineshop.com%2Fdocuments%2FTesting%2520Machine%2520Tools%2520(Dr.Schlesinger).pdf&usg=AFQjCNGqrd3kDuCqc0Ar5B0X-9Wo6hOnKw&sig2=9hZJVcoIkf8G9gguEkS9LA&bvm=bv.129391328,d.amc&cad=rja
Good reading here. For a Tool Room Lathe, which is surely what you have have, it suggests 0-.01/300mm high at the end of the test bar and 0-.005/300mm out (resisting tool pressure) in the horizontal plane.
So it would seem 0-.0004" high at the end your test bar in the vertical plane, and 0-.0002" toward the operator in the horizontal plane.
ewlsey - Thank you very much. I had forgotten that Rich had given that to me a while back. Your post reminded me, but I appreciate your boiling it down to the result for me. There is not enough hours in the day, lately.
ZK the center portion of the headstock should be relieved and sitting on it's cast in pads on each corner. Blue up the ways and slide the headstock back and forth then check contact on the headstock. Then scrape away and repeat many times
. The test bar calculations on my miller test bar was .00017 sag at the end of the test bar if you want to take that into account. My round dial had .0001 max run out the entire length of the test bar. Be sure to check both at the headstock end and far end of the test bar to make sure it is seated properly in the jarno 12 taper in the headstock. A couple of people have had burrs in the taper myself included. I can sympathize with the amount of work involved in getting it aligned properly.
Yes, we are on the same page so far. ( including the scrape, rinse, repeat...
) My spindle taper did indeed have some fair amount of small burrs, introducing runout. In fact, that is exactly why that internal scraper is sitting on the ways, in that picture.
That alone was more work than I would have liked, truth be told.
If I remember correctly Richard said to point the headstock .ooo2 up and towards the operator. That way when facing off something it will have a slight dish and not a crown. Bob
My take is that the test bat setting at "0" or .0002 pointing out at the far end is not for tool pressure, but rather assures that when facing the surface produced will be flat to slightly concave (not high
in the center...... Error exists in everything, here you just want to be sure the error is not producing a problem surface.
Cheers Ross
I think you should wait and do the headstock after you do the saddle.
Wouldnt you want to use the spindle axis as reference for perpendicular travel of the cross slide while doing the saddle? So align headstock axis to ways horizontal and vertical then use that axis to align carriage x-slide travel for perpendicular?
And there it is.
Cash and I have had this conversation at
least 12 times. I am going to write down what my thinking has been thus far, leave this open for discussion, and be willing to learn, challenge my current belief, and learn something if I can.
I have been working with the understanding that
in a perfect world, the spindle should be perfectly aligned parallel to the ways and horizontally as well. Now, we know that there are considerations made for droop and tool pressure, but for now let us disregard those considerations and consider the topic of alignment for what I will refer to as "cupping" to make things simple, here.
I have always heard procedures described as aligning the cross slide
past ( just slightly ) perpendicular to the spindle axis ( usually .0002" across a ground parallel or other flat affixed to a face plate ) to achieve this cupping. My point being that I have never seen it described as aligning the cross slide perfectly perpendicular to the ways. ( noting that this would assume that the headstock would then be aligned off of true parallel to the ways... )
So which is it? Is the headstock canted to achieve the .0002" of cupping? ( and the cross slide is actually truly perpendicular to the ways ) Or, is the headstock truly parallel to the ways? ( and the cross slide intentionally misaligned off of true perpendicular to the ways )
Now, where it gets confounding for me is that it is an easy answer if one is only aligning one or the other on an otherwise good machine... One would ( as Rich points out ) align for the result, knowing that the overall machine is aligned to the ways. But we are not there right now. So a person can
easily see how one could chase their virtual tail about it.
I am in a good place with this, as I can
easily stop and switch to working on the saddle. It really does not matter one way or the other to me, aside from wanting to do it
correctly.
So what is it to be? What say ye?
Your set up on the steady rest seems to me where a lot of your error is.
How so, Rich? I am willing to change it, but I don't see how that has anything to do with the head moving when I tighten and loosen the clamping bolts, or what it has to do with the bar's seat in the spindle. What am I missing?
ZK can you call Monarch and get the factory test sheet for these tests?
Yes, Sir. Sure can. I
may even have them in my factory manual. I'll check tomorrow.
Did you replace the headstock bearings or check to be sure they are tight?
I did check the spanner nut behind the front bearings and it seems tight, but I am wondering just how one knows when it is tight enough. ( and how to actually tighten it, in there )
ZK: Is the the test bar threaded for a drawbar or just lightly tapped to seat it? Just got my loaner Peterson test bar a few days ago and have not even taken it out if the oiled wrapper. Million other thing going on..... We all need more time in the day
Hi gernoff - Boy howdy! You ain't just whistlin' Dixie, there! I could use another 6-8 per day... No, this test bar is not tapped in the rear. It is a borrowed one as well so I cannot modify it.
This is very good news as it is good to see I am not the only one who had lots of fun aligning the headstock
It is even better when the headstock moves slightly when you tighten the bolts down.
Took me a few days of a few hours here and there. But I ended up getting it nice.
Also watch it does not hit on the quick change gearbox. With a ground bed, it will be higher then it was before as well.
RC99 - Haha! Cheers, mate. Some club members can recognize other club members from across the field, it would seem.
I thought I had checked to see if it was hitting the gear box, but obviously I have missed something. I will report back with what it is when I find it.
Zahnrad,
Looks like you are doing a fine job of it..
Getting .0002 or so be sure to turn the spindle 180 on the bar so you might take the average.
Plus I like to blue up a test bar and test the taper 180 apart. Have found a small hone-able bug that can throw at test off a tad.
Thanks, Buck. But all evidence to the contrary right now. Yes, though - I am bluing and rotating the bar to average the difference.
I think Z is going to raise the TS after and he will align the TS to the HS via test bar I think.
Yes, Sir. You are correct.
You can see in the Moore Book they use the Last Word indicator. We would flick the indicator with our finger to be sure it was touching when we got it super close.
Ha! I am always tapping my clock faces to get see if they move...
Aww, Richard It was only .00013 low at 14" and I was tired after all that scraping.
Bob
Yeah... this is a lot like
work...
Thanks, all. Looking forward to hearing more.
