Member postings for mick

Right I'll have one last stab at trying to get to the bottom of this problem. I'm no expert at machine maintenance, but having been a machinist for most of my working life I have a pretty shrewd idea of how to adjust various parts of most conventional machine tools.

I've gone back to the Myford operators hand book.

First unlock the RH ring towards you. Then the LH ring same direction until the outer races are again locked. Undo the back adjusting ring and advance by hand till met with resistance, this now has the inner races adjusted. Slacken off the LH collar one turn + a bit. Tighten the RH collar until the spindle cone and front bearing close to give zero clearance. Slacken RH ring by 0.250'' or 15 degrees rotation to obtain correct clearance between spindle cone and front bearing, tap spindle end with copper mallet to ensure the clearance is applied and check for free rotation. Tighten LH collar to secure adjustment. Pump oil into the front bearing using an oil gun placed in the front filler cap. Pump oil into rear bearings. Using the tail stock revolving center apply pressure to the spindle as if drilling, here the spindle will stop as will all the drive pulleys. When the pressure is released the spindle starts to rotate again, which would suggest that the spindle is being forced back against the bearing cone, so the rear bearings are not holding the spindle adjustment and allowing the small degree of movement to stop rotation. Any ides would be gratefully appreciated.

Thanks.

Mick

Using a tailstock slows the spindle as well, thats why it has to have something to do with the front bearing, but if its adjusted as per the Malcom gospel I can't think what else to do, I was hoping that someone may have experienced the same conditions.

Sorry to have to bother the collective brains again, but I'm not a great deal further on. I've invested in the appropriate 'C' spanner, which makes the finial sensitive adjustment that much more positive. I'm also following Ken Week's step by step gospel according to Malcom to set the adjustment. There is some improvement, as I can now take a 0.40'' deep cut in FC1 with the saddle advanced slowly by hand, but using machine feed is impossible, as the machining pressure still stalls the spindle, but when the tool is backed off the spindle regains its running speed.

The only thing I can think of is that the adjustment between the front bearing cone and the spindle isn't being positively held in position by the rear bearings and so is moving backwards by ten thousandth of an inch locking the two together when the machining pressure becomes too much for the adjustment. There's no discernable movement on the DTI that would indicate where a problem might be. I've tried the adjustment with slight resistance when rotating the spindle, also free rotation when tightening the RH ring, before the finial locking of the LH ring, both with the same end result of the spindle stalling when taking a cut.

The has lathe worked perfectly well during the five years I owned it, the front bearing and spindle cones looked OK when stripped down, so I shouldn't thing there is any oval wear between the two. Any suggestions would be welcomed as the the lathe is pretty much unusable as it is.

Thanks.

Mick

Dural is HE30 by any other name, this I was told by a non-ferrous sales man back in the eighties. The name Dural comes from around the second war when it was a new, strong and exciting alloy, which today is common place.

Thanks again for the constructive advice. I doubt its the motor as the lathe worked perfectly well before the spindle was removed. As there's rain and wind of biblical proportions outside at the moment I'll spend the morning in the shed and start by trying tail stock pressure and see what occurs!

Well thanks for all your help, but after an afternoon in the shed I'm only a little bit further on. I now fully understand the system of adjusting the rear bearings, which is perfectly straight forward when you think about it and the amount of clamping rotation on both the the spindle end clamp and the two bearing rings is very fine between tight and free rotation. I've even had the spindle out again to check every thing, including the direction of the ball race faces are correct. I've adjusted and run the spindle for 15 minutes, then readjusted using the method most recommend, but at the end of the day I still can't take more than a 0.020'' deep cut in FC1 without the spindle stopping, which must mean that the spindle cone is being forced back into the front bearing causing the spindle to stop. I expect that only a couple of ten thousandths of an inch are involved, as there's no end, or radial movement when checked with a DTI. I'll just keep on with the adjusting and hope to get lucky!!!

Hi. Dave. your explanation is a lot clearer than the manual which didn't make it abundantly clear that the setting of the zero clearance between the spindle cone and the front bearing is achieved using the spindle locking ring and not the the bearing clamping rings. I'll give that a go this afternoon, or when it starts raining, which ever comes first. On reflection stall was the wrong word to use, rotation stopping due to the cutter contacting the work piece, then rotation resuming when the cutter is pulled back would have been better.

If its a 1mm pitch and 22 diameter the hole should be 21mm diameter. Just subtract the pitch from the major diameter.

I had to remove the spindle of my Super7 in order to release the back gear, which had become difficult to disengage, I then reassembled the spindle and adjusted the bears according to the instructions in the hand book.

The problem now is that the spindle stalls at the smallest cut, which means there is still movement which forces the spindle cone against the front bearing cone. I've adjusted the back bearings in order to push the spindle forward off the bearing cone, then adjusted the spindle lock ring and readjusted the bearings to create zero clearance between the bearing cone and the spindle. It takes a bit more than the 0.250'' release of the back bearing ring to free the spindle, but every time I try to stop the stalling I get the same result. Any ideas, as I can't be the first to have this particular problem. Thanks

You think you've got problems, I ordered £340 worth of material from MK metals on 08/12/2014 which took four months to arrive and even then was one piece short, which finally arrived two weeks ago!!!!

Thanks Steve. All I wanted was a key to replace the one I lost when I removed the spindle on my Myford, not start WW 3!!!!

Does anyone know where I can get hold of a couple of 404 Woodruff keys

Wouldn't be the first time I've turned the knurling off a cap screw to fit a counter bore!

Converting between the two systems is very straight forward. To convert from imperial to metric just multiply the decimal equivalent of the fractional dimension by 25.4 Metric to imperial, divided by 25.4 As for threads, the smaller metric sizes from 5mm downward are as near as dam it to BA with the added advantage of it being easy to source fixings such as socket head cap and counter sunk screws in metric sizes. Who would ever know that instead of 7BA you used M2.5.

I bet nobody's taken wind speed and coastal drift into consideration!

Did anyone notice if the reconditioned drill worked?????

For a short while I worked for a blacksmith and he showed me how to case hardening with acetylene. You start of with no oxygen at all, which coats the steel in black soot, then you use oxygen to heat the steel to red heat, then a repeat coating of the soot and heat to red. Do this tree or four times, then quench after the last heating. Seems that the soot is pure carbon and the heating soaks into the surface. Useful to know, but I always use Kasnit!!!

Suffice it to say that all production lathes, capstans and Auto's have rear mounted parting blades, this is for two very good reasons, the first being it won't foul or hit any other tooling while being indexed, the second and more importantly is that after a hundred years or so its been proved beyond any doubt that its where it works best.

Sounds like a core drill that's designed to follow a pilot hole and produce a nice true and size hole without the web snatching that would probably occur with a twin flute.

Wish I had a fiver for every time there's a thread on parting! Using a rear mounted parting tool there's no need to reverse the motion as the tool is inverted, you only reverse when using an inverted parting tool in the front tool holder and yes this could spin the chuck off under some circumstances.