Member postings for Morgan Sweet

Thanks Noel, not withstanding the price of oil now, I shall heed your good advice and it will be just a couple of drops.

Thanks for the replies; the motor has a cup (not a cap as I earlier incorrectly wrote) so I will lubricate with Nuto 32.

I have a Brooks Compton Parkinson 370W motor fitted to my Myford lathe and notice that it has a lubrication cap, does anyone know what is a suitable oil and how much and often the motor should be lubricated?

Paul, I have the same motor running from the same vfd on my Myford 7 and have wired it for delta/mesh as shown above by Bill Peak4 with a protective earth connected to the motor terminal earth with continuity to all metal parts of the lathe and all is ok.  

I also added a potentiometer with on/off and fwd/rev switches as per the easy start guide.

Easy Start Guide - WEG CFW300 Frequency Inverter (inverterdrive.com)

Edited By Morgan Sweet on 31/05/2022 15:00:47

Many thanks for all the good advice, the test piece is protruding 7 1/2 " but the collars are about 6" apart. I have increased the rpm with the potentiometer and slowed the feed to the minimum. I am using what I think is a knife tool and have applied a slight radius on the point and lubricated the test area with some thin oil and have a half thou difference between the two collars and the finish has much improved on the outer collar. I think I will leave it at that and start using the lathe (as suggested) to play with. I did receive some formal training on turning but that was over 50 years ago and I have forgotten most of what I did learn. All the tools for the Myford quick change post seem very small and delicate compared to what I remember on an industrial lathe but the lathe seems to be well constructed and I shall start to try some model building after first getting some much needed practise.

Incidentally where do you model makers buy your metal material from?

Morgan

Edited By Morgan Sweet on 27/05/2022 21:33:21

Thanks for all the replies, I'm trying to align the lathe so am not supporting the test piece. If I do support the piece in the tailstock the finish is consistent. along the length. I am using the power feed (too much arthritis for hand feed) at the slowest speed to cut the test rings but have just realised that I think the micro-meter dials on the lathe are metric not imperial and I have been taking too deep a cut; the steel is also of an unknown type. I will try the helpful suggestions and see if I can eliminate the chatter. and poor finish at the far end test ring.

I've managed to get my Myford Super7B turning with the aid of an inverter and have wired in a potentiometer and switches for on/off and rev/fwd and all is working. I have no precession level so have levelled the lathe the best I can with a cheap 6" bubble level and am turning a test piece of steel about 6" long and 1" diameter (relieved in the middle section) and can get the two rings pretty close to the same diameter, however the finish on the section close to the 3 jaw chuck is smooth like a mirror whilst the outer section is rougher and grooved and makes a chattering noise when I turn it. I have tried different lathe tools and tool angles with minimum overhang but the outer ring is always of a poor finish compared to the inner ring. Any thoughts?

Thanks for all the replies especially the link provided by thor.

I have plenty of oil thanks, it was just to check that I am using the correct oils.

I have noticed that for a Myford Super7B some have recommended Nuto H32 & ISOVG68 (K68)or similar oils. I have long lost my Myford manual and use Nuto H32 but have always used a straight SAE30 motor oil where the ISOVG68 (K68) is now recommended. I'm sure that my lost manual use to state SAE30 oil, have I been using the wrong oil in the gearbox etc.?

Thanks for all the information, I have probably got emergency stop type switches etc, and potentiometers hanging about to make up a control pod. I assume the potentiometer used to control the speed is just a linear one as opposed to logarithmic.

Thank you all for your replies; am I correct in thinking this would do the job?

https://inverterdrive.com/Catalogue.aspx?search=atv12%200.37kW

(sorry I did not know how to put a link in.)

If this is ok then could I run it directly from this and add pots and switches to control it later?

I am still a bit confused on wiring it, I presume that you wire from the vfd directly to the motor bypassing the Dewhurst reversing switch, also I notice from Steviegtr's helpful video the belt position he used. Is there a set position for the belt to be left in as I understand that you can vary the speed using the vfd, or am I not understanding something?

Edited By Morgan Sweet on 21/11/2020 12:05:18

I've a Super7 with a brook crompton parkinson 50 Hz, class E, PM0.5, 370W motor that was used on a 3 phase supply but I can wire it as mesh/delta for 240v. Does anyone know a suitable inverter/vfd to buy to run the lathe on a domestic single phase supply.?

I have little knowledge of inverters/vfd so would like an easy to set up type.

If this is possible what belt/pulley configuration would you run the lathe with when using a inverter/vfd?

Peter, your reference to "mils" above as a measurement of 0.001" is quite correct.  Also was  Strowger not an American?

Edited By Morgan Sweet on 12/05/2012 20:48:21

Edited By Katy Purvis on 01/06/2015 12:27:04