|Mike Donnerstag||11/01/2019 08:59:45|
47 forum posts
I recently purchased a Myford Super 7 with gearbox and power cross-feed, made in the early eighties. The lathe was missing the felt wiper and housing, normally attached to the carriage. I noticed that two of the four screws that would have secured it had sheared off and will need to be drilled out or new holes tapped. Can anyone advise me on how to remove the carriage? Is it possible to remove the carriage without removing the apron and lead screw?
|Chris Trice||11/01/2019 12:44:08|
1360 forum posts
Yes. You don't state if you have a power cross feed version or not but the answer is still yes. Firstly withdraw the cross slide and top slide and remove. Undo the allen screws holding the the apron to the carriage and let it drop slightly. For ease of removal, remove the carriage locking screw and its eccentric and loosen the gib strip screws. You can now slide the tail stock off the bed to get it out of the way and then slide the carriage off.
|Chris Trice||11/01/2019 14:05:27|
1360 forum posts
Sorry, you did state power cross feed. How did I miss that?
|Harry Wilkes||11/01/2019 14:25:07|
669 forum posts
Had the same problem but managed to get the two broken screws out using a very pointed centre punch, in my case the screws were 4BA X 3/8 round head.
Good luck getting them out
|Fowlers Fury||11/01/2019 16:14:30|
320 forum posts
If all else is OK, why do all that dismantling? 2 screws ought to be sufficient to retain a wiper + plate.
|Chris Trice||11/01/2019 16:55:50|
1360 forum posts
Home And Workshop Machinery have genuine Nottingham felt wipers available bought from Myford when they closed.
|Howard Lewis||12/01/2019 16:39:05|
|1931 forum posts|
Presumably sheared when an over long screw bottomed in the hole.
No chance of being able to access the stub with a small cordless drill, to start opening up towards tapping size. (Obviously the need is to get close as possible to the centre point )
Minimise, as much as possible, the amount of disassembly, so try to remove the broken stub with everything in situ. the more that you take apart, the more that you have to put back again, and adjust accurately.
You could possibly try using a left hand drill on the sheared off screw. With a bit of luck, it will bite in hard enough to start the stub unscrewing. It it does, it can be unscrewed by hand or with a pair of pliers. Being 4BA, you will need a small drill of course.
No chance of being able to access it with a small centre punch and start unscrewing it?
Another remote possibility might be to make up a tiny chisel, (4BA tapping size or less)and to try rotating it anti clockwise whilst hitting it on the end with a small hammer. It would be nice if the tool bit in and the rotation combined with the shocks, started the screw moving..
Even if you can manage to drill down the middle of the screw remains, do not use an "Easyout", even if you can find one small enough. Unless you are lucky, this is likely to expand the remains and jam it even tighter. A friend of mine from the Toolroom described Easyouts as the most misnamed tool!
|1156 forum posts|
If, as suggested above, you make up a plate to retain the felt then the plate could be used as a drill jig to assist in drilling out the broken screw.
|Mike Donnerstag||12/01/2019 23:10:50|
47 forum posts
Thanks everyone for some very useful replies. I ended up removing the saddle, though with the power cross-feed apron it wasn't quite as easy as Chris Trice suggested, as I had to remove the rear saddle strip to tilt the assembly enough to clear the apron gearing.
Removing the saddle gave me a chance to clean it throughly, free off a seized eccentric for the carriage lock and drill out the broken screw. I ended using a screw extractor held in the pillar drill chuck, rotated by hand, which worked perfectly. I thought two screws had sheared off, but it turned out that one hole was just full of dirt, not a broken screw.
As for the felt wiper and housing, I decided that, since it plays a key part in 'bed preservation', I'd bite the bullet and order ones from Myford.
Once again, many thanks for all your help.
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