Fitting new motor and VFD to a Super 7

[John HaineParticipant @johnhaine32865]

As a New Year project I'm wondering about fitting a 3-phase motor and VFD from Newton Tesla to my big-bore S7, having got fed up with the crude and vibration-prone single phase motor. The worst aspect is the horrible shock it gives the lathe when starting in the high speed range. One aspect that caused me some concern was actually removing the poly-vee pulley from the motor shaft as the s/h set screw seemed to be seized solid, but a more determined attack with an allen key the other day managed to loosen it and actually the pulley then slid off easily. The motor shaft has a keyway and a key (I have seen here that some Myford versions just have the set screw in the key slot). When I refitted the pulley I found out one reason why the screw was so tight – starting in HS range actually loosened. the key. I have managed to refit the pulley and tighten the screw enough to secure it I think, though access for a key is very awkward. So I wonder if other people have done this and have any advice please?

1. Was the new motor a direct fit on the motor mounting plate or was any fettling needed?
2. Is there any provision for axial adjustment of the motor to help in lining up the pulleys with the headstock?
3. Any tips for access and methods to tighten the set screw?
4. I will have to move the lathe on its stand to get access to the motor as it sits against a wall – any suggestions as to how this can be done?
5. Any other tips or advice?

Thanks in advance for any information!

[John HaineParticipant @johnhaine32865]

[Ramon WilsonParticipant @ramonwilson3]

John I'm not sure how long ago it was but I fitted a Newton Tesla unit to my Super 7 having seen a friends lathe who had just done similar.

It proved extremely straight forward to install and set up – when it comes to anything electric other than the most basic I'm a complete numpty so was really pleased with that aspect. Though I cannot recall where from I used a (new) motor from a different source to reduce the initial outlay but everything fitted without any issues and performed faultlessly from the off right up to date – just been machining pistons for the latest build this morning. My lathe is bolted to a substantial bench against a wall. Though it required a degree of contortion on my part I did manage to fit the motor without moving the lathe (or bench!)

It made a noticeable difference in electric usage – according to my wife – I put that down to not having that amperage draw on start up. I cannot imagine in the slightest of going back and should the worst happen would unhesitatingly fit another.

Excellent service from Newton Tesla at the time – no connection just extremely satisfied with the product and company.

Hope that helps some – good luck with yours – you certainly won't regret the outlay

Tug

[bernard towersParticipant @bernardtowers37738]

Plus one for that Tug, one of the best mods you can do jog and speed control is second to none. You can find ideal turning speeds at the twist of a knob. Don’t know if anyone else uses the facility to preselect the direction when the lathe is running, I use it when winding taps out , all you do is preselect the opposite direction and as you are rotating slowly you press stop and then start and it reverses.

[DMBParticipant @dmb]

Hi John,

Happy New Year

Time flies, could easily be 10 years ago that I bought the VFD and 3pfase motor kit from Newton Tesla, already wired up, just plug n go, as upgrade for my Myford S7. Straight forward fitting apart from the difficult access as lathe against shed walls. Wonderful piece of kit, wouldn't hesitate to get another if the need arise. Can thoroughly recommend it.

Another John

[Harry WilkesParticipant @harrywilkes58467]

Hi John

Fitted VFD and motor on my S7 around 4 years back purchased from Transwave no problem with fitting and no issues since

H

[Philip RoweParticipant @philiprowe13116]

Posted by John Haine on 28/12/2021 13:00:24:

1. Was the new motor a direct fit on the motor mounting plate or was any fettling needed?
2. Is there any provision for axial adjustment of the motor to help in lining up the pulleys with the headstock?
3. Any tips for access and methods to tighten the set screw?
4. I will have to move the lathe on its stand to get access to the motor as it sits against a wall – any suggestions as to how this can be done?
5. Any other tips or advice?

Thanks in advance for any information!

1. Direct replacement, just make sure you buy the correct motor shaft size i.e. 5/8" or 20mm dia.

2. Axial adjustment isn't needed, just slide the pulley along the motor shaft to line up with the counter shaft pulley.

3. Can't comment, mine came undone easily and tightened easily with a long ball ended allen key.

4. I used a crow bar to tilt the lathe to enable me to insert some old gas barrel under the stand and rolled the lathe forward on that. Beware of over tilting the lathe as it is very top heavy.

5. Although I used a Transwave system, the principles are the same. It really is a very simple operation and you will wonder why you hadn't done the change years ago as it makes a tremendous difference to using the lathe.

Phil

[John HaineParticipant @johnhaine32865]

Thanks for all the encouraging replies, now just waiting on some answers from NT before ordering.

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