Member postings for old mart

Since the block is not too big, the cost saving from adding pins would not be much. I agree that the one piece block would be strongest and using a four jaw independent chuck in the lathe would be easy to make 90% of it.

Neils scales are equally at home with the metric system as pounds and ounces, only the weights are different.

https://cdn0.grizzly.com/partslists/g0705_pl.pdfThe picture looks a lot like the museum's drill mill pulley fitting. The thread on that is left hand and there is no key. I downloaded a Grizzley manual pdf for one of their mills and it is very similar.

Edited By old mart on 02/07/2022 18:35:45

Edited By old mart on 02/07/2022 18:39:40

It sounds to me that there is a mix up of imperial and metric. The metric spigots on Mitutoyo indicators don't fit the holes in older Eclipse stands and vice versa.

The Tom Senior light vertical that the museum inherited had a MT2 spindle which I was not going to tolerate. The R8 spindle lower half was bought from ARC, a spare part for one of the Sieg mills that they sell. It was a relatively simple upgrade and the two part spindle runs very well indeed.

I did say "if you have a choice", and Ketan has given a pretty comprehensive explanation.

Oh dear, how the mighty have fallen.

**LINK**

I always say that if you are in the fortunate position to choose between R8 and MT3 spindle fitting, choose R8.

I would cut up some empty aluminium drinks cans for shims and try fitting it between the channel and the hoop. Use clamps or mole grips to squeeze the parts together. You may have to carefully separate them with a hammer and drift. The object is to stretch the channel slightly. Extra shim thickness mught be needed. If you have a vise, the job would be much easier.

Because of the unavoidable clearances required for the mechanism to work, there is likely to be a slight difference in the workholding accuracy dependent on which pinion is used to tighten the jaws. Only by testing using accurate test pieces can the master pinion be found. That is the least inaccurate one. I use the test bar which is about 3/4" diameter and a Morse taper socket with a 2" diameter ground cylindrical outside. Simply tightening the jaws on a workpiece is not good enough, you should move it in a circular motion as the jaws come in contact until tight. Tests should be made on each pinion and the best results recorded. As many different diameter test pieces as possible will check the accuracy of the scroll.

If setting up to grind the jaws in situ, then one of the pinions should be chosen and that will be the master. Unless the chuck is well worn, the differences between pinions will be minimal and having a master jaw would only be needed for critical work. For instance, turning and boring and then parting off without disturbing the workpiece in the chuck will be exactly the same with any chuck, good or bad.

Can you check the runout of the left end of the spindle to find if it coincides with the right end? If you were to remove the left end bearing and clean it before replacing it, the inside and outside races would end up in different positions to where they are now, which might change the unusual charactistics. Building up the oil film before testing has already been mentioned. Link belts may help if there is a suspect stiff belt section. The odd behaviour is annoying, but not a vital flaw, I wish all the machines I use were as good as your lathe.

Firstly, you would be better off getting metric bearings as they tend to be cheaper than imperial sizes. You should choose sealed bearings considering the abrasive nature of the grinder, 2RS is a common designation in the bearing part number.

 I use Simply Bearings for most of my bearing purchases.

Edited By old mart on 20/06/2022 17:34:25

That centre pulley is designed to pivot on the centre column axis to make changing the belts easier when the motor is moved as far as possible in the slackening direction. The pivot never needs tightening.

 If the pillar drill does not have the centre pulley, then you should investigate ways of getting the motor to move slightly further in the slackening direction.

Edited By old mart on 19/06/2022 19:26:38

Beryllium copper is most often used to make springs. When I was in plating, we used to get large batches of small pieces and gave them a dip in hot 70% sulphuric acid. I cannot remember if that was to pickle them or some heat treatment. I often wonder how I survived my early years.

I can loose 1/2" bolts in the swarf in the lathe, no bother.

It's amazing what a little careful restoration can do, I'm glad to see that you did not try to "over restore" like many people do.

Welcome to the forum, Edward, if you can post a picture, there may be clues from the design where the joint is to unscrew the halves. Try putting "posting pictures" in the keyword box, there are several tutorials showing how.

I can see the principal and it should work every time, but you must be sure that one of the flutes is exactly in line with the spindle to work axis when you make the measurement. For example, if the work is only 1mm thick, it would be possible to position a four flute cutter exactly between two flutes which would not be on the outside diameter.

For truing up work in a four jaw, I go for the lever type indicator rather than the plunger dti.

Your particular spindle has the splines rather than the drive key in a slot, the bush no.13 in the drawing is likely to be two needle roller bearings to support the front pulley. Otherwise the removal from the quill should be the same.