By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

Myford Super 7 with 'Big Bore Conversion'

All Topics | Latest Posts

Search for:  in Thread Title in  
Michael Gilligan24/09/2018 07:16:48
avatar
15479 forum posts
668 photos
Posted by Nick Hulme on 23/09/2018 23:08:49:

It's my assumption that it has just one taper bearing front and another at the rear as it uses a split adjusting ring clamped with a cap screw at the rear of the headstock, I've not had to strip it yet so I don't have bearing details.
If I ever do strip it I might convert my "spare" head too,

.

Thanks for that, Nick yes

MichaelG.

Paul Smith 3703/04/2020 23:10:21
avatar
66 forum posts

Digging up an old thread,

NIck..Did you strip your headstock and have you any details and bearing numbers? Ive contacted Roy Milner and hes not making any more big bore headstocks.

So i may attempt it myself with a bit of help.

Thanks Pauly

Nick Hulme05/04/2020 13:43:55
743 forum posts
37 photos
Posted by Paul Smith 37 on 03/04/2020 23:10:21:

NIck..Did you strip your headstock and have you any details and bearing numbers? Ive contacted Roy Milner and hes not making any more big bore headstocks.

So i may attempt it myself with a bit of help.

Thanks Pauly

Pauly,
I haven't needed to strip it yet and it's used every day for production work at the moment, I currently have a rush of orders owing to people being at home with nothing to do but fit upgrade parts to their projects.
When I get around to stripping it I will put all the dimensions into CAD and I have an idea or two for improvement when I convert my spare head,
Regards,
Nick

John Haine05/04/2020 14:08:49
3012 forum posts
160 photos

I have a Myford "big bore" S7 and frankly an MT4 taper is a pain! Apart from anything else you can't get any MT4 tooling to fit because the taper is shortened - I bought an MT4 arbor from RDG (why own Myford?) to make a tool setter and it was too long! The only MT4 thing I have is a short plug with an MT2 hole supplied with the lathe by Myford - why on earth they didn't just make it ER40 in the first place I don't know.

Nick Hulme05/04/2020 14:23:10
743 forum posts
37 photos
Posted by John Haine on 05/04/2020 14:08:49:

why on earth they didn't just make it ER40 in the first place I don't know.

John Stevenson suggested a native ER40 headstock would be the best option for the Super 7, I think Myford were just making a point of ignoring him and common sense by finally employing the MT3 design which one of their employees had come up with in the 1960s or 1970s.
Perhaps the "New Myford" will go with ER40 sometime in the middle of this century!

Edited By Nick Hulme on 05/04/2020 14:23:42

Paul Smith 3705/04/2020 14:39:13
avatar
66 forum posts

I thought you could get an MT4 to MT2 adaptor? This one

Howard Lewis05/04/2020 17:57:20
3148 forum posts
2 photos

On the face of it, holding a MT sleeve in an ER collet is merely involving another possible source of error.

Although would it be as great as using a 4MT / 3MT sleeve?

I have to use a 5MT / 3MT sleeve in my mandrel, and am unaware of problems.

Maybe that's what comes of not looking for them!

Howard

Derek Grant05/04/2020 21:01:15
2 forum posts

Hello all you Myford experts!! I have been exploring the Bigger Bore question regarding the Super7. I need 25mm clear borein the spindle and would appreciate any help you can give. Please be gentle with me

Regards Derek.

Paul Smith 3705/04/2020 21:13:53
avatar
66 forum posts
Posted by Derek Grant on 05/04/2020 21:01:15:

Hello all you Myford experts!! I have been exploring the Bigger Bore question regarding the Super7. I need 25mm clear borein the spindle and would appreciate any help you can give. Please be gentle with me

Regards Derek.

Well so far ive gleaned there were two manufacturers of the big bore spindle headstock, one was Roy Milner who has packed up doing them, and theres Myford themself, who are closed due to the Corona and i dont know wether or not they will supply said big bore spindle headstock on its own as a kit. Regs Pauly

Mike Poole06/04/2020 23:03:41
avatar
2544 forum posts
60 photos

I doubt it would be practical to build a big bore headstock from parts, it would be a long and expensive shopping list. It would make more sense to part exchange your current machine for a big bore I would think.

Mike

Nick Hulme07/04/2020 14:09:57
743 forum posts
37 photos
Posted by Mike Poole on 06/04/2020 23:03:41:

I doubt it would be practical to build a big bore headstock from parts, it would be a long and expensive shopping list. It would make more sense to part exchange your current machine for a big bore I would think.

Mike

That's what Roy Milner did, with most of the parts being taken from the headstock being converted, no new gears or pulleys were used.

Paul Smith 3707/04/2020 17:34:56
avatar
66 forum posts

I just wish it were documented somewhere.

Mike Poole07/04/2020 18:53:25
avatar
2544 forum posts
60 photos

I have seen some pics of Roy’s conversion, a talented engineer no doubt. I think the smallest sheave of the cone pulley is lost so I would think the back gear would need a couple of new gears and the gear that drives the screw cutting train would need to be larger, the chuck backplates will need remachining or replacing, the tumbler reverse for the leadscrew will need work also. It’s not a trivial task to undertake if you wish to copy Roy’s solution. Nearly every part of the Myford big bore headstock is different from the standard bore machine.

Mike

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

Support Our Partners
Allendale Electronics
Ausee.com.au
cowells
Warco
emcomachinetools
Eccentric July 5 2018
ChesterUK
Eccentric Engineering
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