info requested on union graduate bowl lathe

[graduate_owner]

Hi Ian,
I'll be back in the workshop after a cuppa, and I'll try shifting the pulley then. As you say, a blowtorch may work but I didn't want to try that until I'd found out about any possible alternatives.

My idea on the adapter to fit a myford (or whatever) chuck is as follows:-

turn up a shaft to go through the headstock from the outboard end, with a shoulder as a stop. On the inboard end a nut on a threaded portion will be tightened up to stop the shaft from sliding out.

Back to the outboard end - after the shoulder, a LH thread to suit the chuck, and two flats on the shoulder to be able to grip with a spanner for tightening / removing. BUT - if it's not a taper fitting then the whole thing relies on the tightness of the inboard nut to stop it from slipping in the spindle. Perhaps a MT3 sleeve to help with both grip and alignment may help. I'm going to ponder over that one a bit more.

The alternative is to make up an adapter which screws on to the LH spindle, but internal LH thread cutting is not easy, especially so for a beginner to metal turning. I can't find a supplier for these, and to have one specially machined could be almost as costly as buying a new chuck anyway. Things would be SO much easier if manufacturers standardised their products.

Perhaps the way to go is to buy something like Axminster's new stainless steel chuck for £160 plus jaws, but considering I already have Myford accessories (and the fact that I paid £150 for the graduate!!), this seems a bit out of proportion.

Anyhow, first let's get that pulley loose!!

K

 

[flh801978]

I have the patriot chucks on my lathes but thats more to do with the fact that sorbys factory is less than a mile away.

£150 is a bargain I have sold surplus sanding tables for more than that

 

[graduate_owner]

I've just come back from the workshop. The pulley came loose after some gentle heating and tapping, and I fitted a vee belt from a collection I acquired a while back. Getting the spindle back took a bit of tapping as well. In the end I knocked up a sort of pullers (threaded rod through spindle etc) which I tightened as I tapped, and that kept the pressure on.

I didn't know the collar on the outboard side (with the grub screw in) moved independently of the spindle, so I didn't have a reference mark to align it up again. It was too late after I'd tapped the spindle home - I didn't want to take it all loose again so I've put the grub screw back and I hope it's OK - may not be in the locating hole in the spindle though. I'll try it and see, and dismantle if necessary.

Next job is to tackle the motor.

Yes I paid £150 - it was offered as 'buy it now' on that well known internet auction site at £250, then £200, and no takers. So after the auction finished I contacted the seller and he agreed on £150. It came with the sander based on a 14" aluminium faceplate, complete with graduate cast iron table (no mitre fence) and a dust extraction shroud. It cost me about £30 in diesel to collect it so I was very pleased.

I'm looking forward to actually using it now. I don't know if I want to keep the sander as it means taking it off each time I want to turn. I might try mounting it on the inboard side, but if it gets too fiddly I'll try to sell it on. It's interesting to know they fetch decent money- might pay for a chuck or perhaps a stand alone sander.

So how come you have 4 graduates, and sell parts - are you a dealer or do you collect graduates like some people collect stamps!!

K

 

[flh801978]

I have all 4 in my workshop one long bed two short bed all set up for turning and a pedestal set up for sanding all 3 phase with VFD's I bought them all off ebay and sell off any parts I dont need so at the end of the day most have ended up FOC

 

[graduate_owner]

Wow! So that's how you know so much about graduates.
You've been incredibly helpful. Thanks very much.
What do you use as a variable speed system?


K

 

[flh801978]

They all have control techniques Commander SK VFD's on them and 1.5 hp motors on the short beds 1 hp on the sander
I do metal spinning on one of the short beds hence larger motor

 

[graduate_owner]

Hi again,
do you notice loss of torque at low speeds?

I have one Eurotherm 3ph inverter which I use for all my various motors (Myford ML8, Viceroy milling machine and motor ready for graduate). It's rated at 2HP and my motors are 1 HP, They are all connected in Delta mode and are 415 / 240volt. However on very low RPM I can switch on while holding the motor shaft with my hand and can stop it from turning. Once I turn up the revs on the inverter then the torque seems fine.

I select the lowest speed on the drive belt pulleys, so that the motor then runs faster and gives more torque. It's fine on my Myford and Viceroy, haven't put the 3ph motor into the graduate yet.

I just wondered if you had found the same thing.

K