By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

Lathe, lowest speed?

All Topics | Latest Posts

Search for:  in Thread Title in  
Goran Hosinsky06/01/2010 20:15:03
41 forum posts
I have to modify the motor setup of my Chinese lathe and would like to take the oportunity to add  a somewhat lower minimum speed than the present 115 RPM. What bottom speed should I aim for? 50 RPM looks to be fairly easy to reach but I see, that the Myfords go down to 30 RPM, which would be rather more difficult, but probably doable.

Goran
Canary Islands
KWIL06/01/2010 20:37:32
3681 forum posts
70 photos
If you fit a three phase motor and use an Inverter you can run it as slow as you like, provided that you watch the motor temperature. I use an almost stopped speed to clock under power.
Goran Hosinsky06/01/2010 20:52:15
41 forum posts
Yes, but I am looking for a locally available, cheaper solution
Tony Pratt 106/01/2010 21:23:36
2319 forum posts
13 photos
Hi, from my experience 50 rpm will be fine. Obviously there will always be that job which needs a slower speed but not too often.
 
Tony
Keith Long06/01/2010 21:37:12
883 forum posts
11 photos
Hi Goran
As Tony says 50 rpm should be OK, if you want to do screw cutting you may want to go lower, but an alternative would be to rig a handle to allow you to turn the lathe over by hand and cut the threads that way. Cutting threads shouldn't take much power (effort) as too big a cut, you'll probably snap the tool anyway.
If you want to go to lower (powered) speeds then I think the easiest way, if your changing the motor arrangement, would be to put in either a very big pulley as the input to a counter-shaft from the motor or look at rigging a two stage counter-shaft system.
Which Island are you on?
Keith
Goran Hosinsky06/01/2010 22:43:34
41 forum posts
With pulley for 50 rpm I do not need to change the protective cover, for 30 rpm I have to modify or make a new on.
 
Isla San Miguel de La Palma, the island with the big observatory
Goran
Gordon W07/01/2010 09:51:10
2011 forum posts
I've just fitted a bigger pulley to my small lathe. Bored out inside to fit over existing pulley, scewed flat plate to outside of new pulley, tapped 4 holes in existing pulley (just missed the second V), this gives me about 60 rpm. Need a longer belt, and end cover has to open, or modify to suit. The new big pulley has a flat top, not Veed, and works OK. I use a mandrel handle for screwing, for short threads, this works fine. Big pulley can even be made from good plywood.

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Shopping Partners
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate