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 alignment. What is good enough?

Late RDM Alignment

All Topics | Latest Posts

Search for:  in Thread Title in  
<< First < Prev 1 2
NJH08/11/2011 11:43:18
avatar
2314 forum posts
139 photos
Hi "Skarven"
 
Well you frightened me at first with your talk of adjustments better than .005mm - surely that's smaller than a mite of dust on the leg of a flea! You then go on to talk of turning some steel of unknown provenance with a tool you acknowledge as not the best for the job. If you are new to this I think you need to give yourself a better chance
 
I'm only a raw amateur here but my advice, for what it's worth, is firstly to use the unknown metal as a doorstop then buy ( probably for less than £10) a piece of free cutting mild steel from one of the advertisers in the mag. You are then assured that good results are possible.
 
Yes the tangential tool holder bits are easy to sharpen and the results are good but there will be times in the future when other tool shapes will be required. Sort out your bench grinder and practice grinding some HSS tool bits - it's not too difficult - and it's a skill you need.
 
Good luck!
 
Norman

Edited By NJH on 08/11/2011 11:45:35

Swarf, Mostly!08/11/2011 12:31:21
753 forum posts
80 photos
Hi, all,
 
I hope the following isn't too far off-topic.
 
I was taught that a lathe should face ever so slightly concave (so that a faced surface will fit a flat surface without rocking). I know that there is such a thing as a cylindrical square.
 
Am I right in thinking that this is achieved by the setting of the saddle and cross-slide, rather than of the headstock?
 
Best regards,
 
Swarf, mostly!
 
blowlamp08/11/2011 13:03:01
avatar
1885 forum posts
111 photos
Posted by Swarf, Mostly! on 08/11/2011 12:31:21:
.
 
Am I right in thinking that this is achieved by the setting of the saddle and cross-slide, rather than of the headstock?
 
Best regards,
 
Swarf, mostly!
 
 
You are.
Everything is referenced back to the lathe bed for alignment purposes. It's got to be or you wouldn't be able to pinpoint which parts are in error.
 
Martin.
Skarven08/11/2011 17:09:07
avatar
93 forum posts
11 photos
Hi Norman,
 
You write:
firstly to use the unknown metal as a doorstop then buy ( probably for less than £10) a piece of free cutting mild steel from one of the advertisers in the mag.

Living in England (or maybe the US) i would do just that. Here I would have to hire a truck and buy 6 m of some steel and the price for 6m 25mm round stock is about 145£ + 25%VAT + freight. I can buy silver steel in 1m lengths. 1m of 5mm silver steel is about 125£ + 25% VAT. Yes I know the price in the UK is about a 1/10 of that!

I'm actually planning a trip to England this winter to buy some materials and other workshop things. I can carry about 40 kg on the plane and 660£ worth. It will only cost the plane ticket extra! You can have a plane ticket for maybe a 100 £.That is covered in the first 5mm silver steel piece!!!
NJH08/11/2011 20:36:30
avatar
2314 forum posts
139 photos
Ah!
Yes Skarven - I see your problem. I guess we are lucky here with good access to reasonably (?) priced bits and it's difficult to remember that others might not be so lucky.
So I guess my post was useless - still Good Luck though!
 
Regards
 
Norman
Stub Mandrel08/11/2011 20:47:23
avatar
4318 forum posts
291 photos
1 articles
I'm with Terry on this one.
 
How many of you folks have heard of the Schelsinger limits?
 
If you adjust your lathe to be perfect with one material/tool/depth of cut or with a dial gauge, then it will be perfectly adjusted for that situation.
 
Change material, depth/rate of cut, tool or even workshop temperature and it will no longer be perfect. The late Tom Walshaw explained all this better than me, but in short the Schelsinger limits are what you should aim for when setting lathes to factory floor/toolroom/precision measurement situations. They allow for errors acceptable in those situations and aim to get the lathe set up so that the errors imposed by tool loads, bed flexing, the weight or flexibility of the work etc. all act to reduce the errors. I.e. the lathe is set to be acceptably accurate and in a way that in practice you won't get errors worse than these. It's very clever and I admit I don't understand everything about it, but it shows that attempting perfect lathe adjustnments is like catching rainbows.
 
Neil
<< First < Prev 1 2

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