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

Colchester MK1 Bantam

Tailstock Morse taper ejection adjustment

All Topics | Latest Posts

Search for:  in Thread Title in  
Rob Thomas 419/12/2020 17:04:02
16 forum posts
7 photos

Please can anyone enlighten me on how to adjust the point at which the tailstock ejects a Morse taper fitting when the barrel is wound back? At present, mine ejects at about 1/4" projection of the barrel, I'd like it to be below the zero point.

Regards,

Rob

Brian Wood19/12/2020 17:13:27
2742 forum posts
39 photos

Hello Rob,

I think this might be common to many tailstocks in that is is related to the engagement of the adjustment thread in the barrel.

Try winding the barrel out until you can feel the thread disengage. Now turn the thread by one rotation and re-engage the barrel to see what effect that has had. If the result is an increase in projection then do it all again but this time turn the thread twice in the opposite direction before re-engaging with the barrel

Regards Brian

Baz19/12/2020 17:33:50
1033 forum posts
2 photos

Rob I don’t think you can adjust the ejection point, I think it is fixed by the end of the barrel thread. Only way that springs to mind is to shorten the tang on whatever tool you are using.

DC31k19/12/2020 18:07:52
1186 forum posts
11 photos
Posted by Rob Thomas 4 on 19/12/2020 17:04:02:

Please can anyone enlighten me on how to adjust the point at which the tailstock ejects a Morse taper fitting when the barrel is wound back? At present, mine ejects at about 1/4" projection of the barrel, I'd like it to be below the zero point.

Short answer, as the others have said, is that it cannot be adjusted. If you want to alter it, you either have to change the length of the tailstock screw or change the length of the tooling inserted into the tailstock.

When you say it ejects at 1/4" projection of the barrel, is that 1/4" of the barrel projecting from the tailstock body or 1/4" reading on the tailstock scale? If the first one, that is normal. If you look at the barrel, it should be graduated. The graduations do not start at the end of the barrel. The ejection is a little less than the zero graduation.

It would also be prudent to obtain a proper drawing of a Morse taper shank and make sure any tooling that you have conforms to this drawing.

john halfpenny19/12/2020 18:12:50
314 forum posts
28 photos

I remember having this problem with my Clarke lathe. In my case it was solved by changing the length of the screw - I had to make a longer one. I recall the end of the screw pushed on the inner end of whatever was in the barrel, in my case a morse sleeve.

Ian B.19/12/2020 18:59:43
171 forum posts
5 photos

The tang is always a problem and I was not able to.make any adjustment on the Bantam I had. I ended up having chucks and tools with arbors and tangs so they could be ejected from quills and another set with tangs ground off for use in the tailstock. Now repeating the ops having downsized. The other trick is to use the arbors of the mill that have drawbar tappings. I just turn up a plug from an M10 bolt leave a bit of hex on it. Thin the head and the ejector pin with send it out board. Finger tight is enough.

Rob Thomas 420/12/2020 13:17:29
16 forum posts
7 photos

Grateful thanks for your replies.

Rob

Howard Lewis20/12/2020 21:05:44
7227 forum posts
21 photos

It will vary according to the length of the fitting in the Tailstock.

Arbors or drills with "normal" tangs eject earlier than dead centres with blank ends, but no tangs.

For arbors with drawbar tappings, I screw in either a screw in tang, or a short piece of threaded rod.

Fortunately, the exact position causes no problems on my machine, because the Handwheel is graduated, but with a graduated barrel I can understand the concern under some circumstances.

If it is vital, could you not fit a DRO to the Tailstock? It would need a collar clamped to the barrel for the "stem" of the DRO, and tappings for the read head of the DRO. But it would allow the reading to be zeroed at almost any point if a more accurate measurement of depth is needed.

Howard

Steviegtr20/12/2020 21:31:42
avatar
2668 forum posts
352 photos

I have just done this exercise on the myford. Because i have fitted a dro on the tailstock neck, i have lost 10mm of eject. I have drilled & fitted a bolt & then locktighted all my lathe only fittings. Like centres. Only trouble was some of the very old ones i have are hardened throughout & not possible to drill. I don't think there is any adjustment on mine.

Steve.

Anthony Knights21/12/2020 08:15:37
681 forum posts
260 photos

For my mini lathe, I get maximum travel by cutting the tang off the morse tapers used in the tailstock. I have also made an adjustable scale to read tailstock travel.

tsscale.jpg

Rob Thomas 423/12/2020 17:35:19
16 forum posts
7 photos

img_0138.jpgFor completeness, here is what I've found for adjustment on Mk1 Bantam.

img_0140 2.jpgI wound in the 1/4"unc screw in the end of the barrel screw to achieve an ejection of MT fittings at approximately 1/8" below the zero point on the barrel.

Macolm27/12/2020 16:10:57
avatar
185 forum posts
33 photos

Belatedly, I came across the spacer piece I made to eject short MT parts on my Bantam. It slides across the slot, then the smaller section is offered against the offending item, and the normal ejection made with the handwheel. Make it a close fit, very similar to photo. While anything that fills the gap might assist ejection, it may get wedged and be very difficult to recover, particularly if ejection fails.

mteject.jpg

It was made from an offcut, and turned between centres.

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
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