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View Full Version : Help Needed to convert a Nova 1624 lathe



Jeff's Shed
20th June 2016, 04:46 PM
Hi, I need some help in converting my nova 1624 lathe to a variable speed lathe. Has anyone attempted to do this?
Jeff :?

Jim Carroll
20th June 2016, 08:25 PM
Save your money and buy a lathe already set up with variable speed.

BobL
20th June 2016, 09:26 PM
I'm part way through doing a VFD conversion on a Nova right now.

Let me outline the complications as I see them.

The existing single Phase motor cannot be used - 3P motor is needed.
It needs to be a 240V Delta connected motor, for a new one expect to pay around $300.
Used 3P motors are pretty common but you need to know what to look for, and have the test gear so you don't get a lemon, and make sure it address the issues I refer to below.

If you cannot find a 240V Delta connected motor a regular 415V non-delta (correct term is Star) connected motor can be converted to 240V Delta.
This is not a job for the faint hearted and is best done by a motor rewinder - I have no idea of the cost.

A cheap VFD will not allow the motor to develop much torque at low revs so to get around that its better to get a motor with double the HP of the original motor so that at least you have some torque at slow speeds. A more powerful motor (e.g. 2HP) will almost certainly have a bigger shaft (24mm cf 19mm on the original motor) which leads to problems described below.

VFD wise, you can pay anywhere over $150.
Unless you know what you are doing the fitting is a job for a sparky.
Most sparkies I know won't deal with with the cheaper VFDs which adds to the cost.

Now for the mechanical issues
The Nova uses a flange mount motor - these are less common that foot mounted motor so you may have to wait a long time to find a used flange mount and even then it may not fit the Nova flange.
A foot mounted motor can be used but it requires cutting out and fitting a foot plate and providing some support for the plate so this includes a bit of welding.

Next there is an uses with the bigger (24mm) shaft on the motor and the 19mm pulley on the Nova .
Solution 1 is to get/make a new pulley - the multi ribbed V pulleys are not cheap! ($100?)
Solution 2 is to bore out the old 19mm bore pulley - this is not really a good idea as it does not have enough metal to ensure a safe fixture to the shaft
Solution 3 is to bore out the old pulley and machine up a steel collar to fix around the the bored out shaft - this is what I am in the middle of exploring at the the moment.

I had the exact same problem with my small Woodfast and ended up making a new multi ribbed V pulley - this is a right PITA.

In summary - it's FAR from straight forward.
If you have some metal working skills, access to a metal work gear, and proper "electrical know how" it is not impossible to do, but otherwise . . . . ..
AS JC says it is MUCH easier to just buy a lathe with the variable speed attached and may not cost that much more, in fact it could be less if you have to get sparkies involved.

Sawdust Maker
20th June 2016, 11:09 PM
Teknatool offer this in the US of A for $599.99

DVR™ 1624 Package Drive Upgrade Motor (http://www.teknatool.com/products/lathes/DVR%20Upgrade/nova%20_dvr1624upgrade.htm)

1624 upgrade (http://www.teknatool.com/products/lathes/DVR%20Upgrade/nova%20_dvr1624upgrade.htm)

QC Inspector
21st June 2016, 12:05 AM
Bob. Regarding the motor shaft size. Solution #4. Have the motor shaft turned and re-slotted to match the Nova Pulley. I'm following this thread as I have the same lathe and want to make the conversion next year. My older lathe's motor doesn't mount to a flange, it has the plate.

BobL
21st June 2016, 12:30 AM
Bob. Regarding the motor shaft size. Solution #4. Have the motor shaft turned and re-slotted to match the Nova Pulley. I'm following this thread as I have the same lathe and want to make the conversion next year. My older lathe's motor doesn't mount to a flange, it has the plate.

Thanks QC, I have had that suggestion made over in the MW forum but I want to do it all myself in my shed and reslotting involves a mill which I don't (yet) have. in my shed.

QC Inspector
21st June 2016, 07:20 AM
I can't remember if you have a metal lathe Bob but you can slot with it if you do. A cutter ground the width of the slot in the tool post and drawn along the length of the shaft with the carriage, a little deeper each pass, will cut the slot. Now if you or the original poster haven't got a metal lathe either then it is all academic. ;)

Pete

Lappa
21st June 2016, 08:27 AM
Teknatool offer this in the US of A for $599.99

DVR™ 1624 Package Drive Upgrade Motor (http://DVR™ 1624 Package Drive Upgrade Motor)



link didn't work - try this
NOVA DVR XP LATHE (http://www.teknatool.com/products/lathes/DVR%20Upgrade/nova%20_dvr1624upgrade.htm)

Jeff's Shed
21st June 2016, 08:42 AM
Thanks to all who have replied with suggestions.
It looks like Jim's solution will be the path I follow. I don't have a mill in my shed although i do know folks who do. I've not done any metalwork since high school way back in the late 60's so i don't think that is the solution. Carbetc NZ (I'm sure AUS do as well, ) offer a complete motor/headstock replacement for about $1900NZ plus freight. a bit too expensive.
The US option seems good but i keep getting redirected back to their suppliers in AUS and no one seems to stock the goods.
I'll follow up some more with folks here in Newcastle before I go with a replacement.
Many thanks to all.

chucky
21st June 2016, 11:59 AM
I agree with Jim, save your money towards a lathe with variable speed already set up to use.