MadModder
The Shop => Tools => Topic started by: John Hill on April 19, 2009, 11:05:34 PM
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... I cut the thin ends off my MT dead centre etc? I have two dead centres, one live centre and one drill chuck arbor which are all so long that the 'pusher-outer' robs me of over an inch of tail stock ram travel.
Will I regret it if I cut them down? Is that metal likely to be too hard to drill and tap? The "Artful Bodger Idea" (all rights reserved) is to cut the offending end off then drill and tap the ends so that an adjusting set screw can be used to set 'push out point' to be near as dammit to the zero point on the ram scale. :scratch:
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What do you mean by a dead center? The one in the headstock or the one in the tailstock.
At some point in history I believe the terms got reversed, ie dead became live. It just depends how old you are I guess to what you call them.
The one for the headstock should be soft, the tail stock one will be hardened. But that does not mean you will not be able to machine it.
You might go through a bit of tooling trying though :lol: :lol: :lol:
Got the T-shirt :ddb: :ddb: :ddb:
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OK, you got me there, yes the terms are obviously wrong though I cant put my finger of the reference..
The centre for the headstock is not a problem, I dont have a draw bar type and there is no 'pusher outer' on the headstock spindle.
The centres for the tail stock that do not turn I have called 'dead centres', the one that has a set of bearings in it I have called a 'live centre' but on reflection I am sure that is wrong.
I am unsure if the two 'dead centres' are the same or not, maybe one is soft. :scratch: OK, if I find one is soft I will not cut it's tail off....
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If you are talking about one for the tailstock be careful, you may find it hard to remove if you make it too short as there is nothing to "persuade" it out with... :thumbup:
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If you are talking about one for the tailstock be careful, you may find it hard to remove if you make it too short as there is nothing to "persuade" it out with... :thumbup:
Good point and it is why I was thinking of the set screw to adjust it for push out from the zero graduation, the ram does go back a bit further than zero.
BTW, isnt it past your bed time? ::)
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Hi John,
You do get some wierd ideas, trying to beat the manufacturers way of doing things.
I fully understand where you are coming from with this, I raised this point with my machine supplier and was told, 'that is just the way it is'.
I did a load of accurate measuring, and came to the conclusion that what I would be gaining in spindle movement, to me, it just wasn't worth the hassle, I will just move the tailstock a little closer to the chuck when required.
It looks like you are determined to go for it, so, as long as you don't try modifying the machine itself to get you where you want to be, I would say try it, but be careful. If you get an MT stuck 'up the spout', don't try to belt it out and free it off from the nose, a couple of bad side knocks will introduce deformation that equates to years of wear, but wind the spindle fully out to remove it, and come in from the back with a drift.
While you are at the tailstock end, maybe you should consider this dead easy mod.
http://madmodder.net/index.php?topic=424.0
Bogs
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You do get some wierd ideas, trying to beat the manufacturers way of doing things.
Actually Bogs I am just trying to help the manufacturer by finishing his job! :coffee:
It is the drilling arbor that is the most annoying, first of all I have to crounch down to read the metric scale (the most visible position is occupied by some archaic scale apparently calibrated by the width of King Arthur's thumb) then I have to subtract some awkward number like 19.5 from the reading! :doh: I am too old for that sort of thing!
I read your anti-rotating-tailstock modification with some interest but so far that has not been an issue for me. However I do have a nice clean rag hanging by that end of the lathe that is used for nothing but wiping the tapers before they go in.
There is another but slightly less annoying issue related to tail stock and centres and that is that when I put some work on the faceplate it would be nice to run up the tail stock to get a fairly close centring before doing the final positioning with the dial gauge when it needs that sort of precision. But on my lathe with my centres I often cant move the carriage far enough left for the centre to reach the work, the problem is partly my making with DRO mounts etc. I think the answer to this particular issue is to turn up an extra length 'centre' which is used for this purpose only.
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John,
I had the same problem as yourself, and raised the issue with the suppliers.
Unlike yours, I couldnt even get the toolpost anywhere near the faceplate. So while they were preparing a replacement machine for me, I had them remove the coiled spring leadscrew guard. That cured the problem, but the tailstock dead centre still showed up as a problem.
The troublesome guard
(http://i202.photobucket.com/albums/aa102/bogstandard_photos/leadscrewcover1.jpg)
The problem it caused
(http://i202.photobucket.com/albums/aa102/bogstandard_photos/leadscrewcover2.jpg)
In the middle is a standard dead centre, the one on the right is a commercial live centre, notice how much longer it is, that would solve your reach problem. The one on the left is one I knocked up out of a few left over commercial bits to make a slimline live centre, so that I could get in a lot tighter with the toolpost.
(http://i202.photobucket.com/albums/aa102/bogstandard_photos/centres.jpg)
John
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I have got a live centre! I just never thought of getting it out for that particular purpose!
:doh: :doh: :doh:
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John H
I use a Live centre to reach the face plate for setting up it works fine :thumbup:
John B
I like the look of that slime line Live centre I'll give it an eye ball next time I'm over.
Stew
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John,
I`ve shortened all the sleeves for my MT2 tailstock.......
(http://i110.photobucket.com/albums/n95/Dayjo/p4200001.jpg)
With only 1.5" of ram travel, lopping over 1/2" off the end made a big difference.
I cut off with the angle grinder, then tidied the cut end in the lathe.
David D
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Nice one David,
Proved to John (and everyone else) that it can be done and it works.
John
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I did my drill arbor, nicked it around with the grinder then sawed it off. :ddb:
I am still trying to figure how to hold it in the lathe to tidy the end.
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Put a chuck on the drill arbor, then a bit of bar in the drill chuck, and hold the bar in your lathe chuck. Then maybe support the end you want to machine with your fixed steady. A little flimsy, but it should let you get the job done.
Bogs
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Thats exactly what I did John but the fixed steady, which I had never used before, needed a bit of 'initialisation' first! But I got all the grub screws in place eventually and it went quite well.
I think I will just counterbore the others, if my drill bits are up to the task, this first arbor was certainly soft enough inside to be drilled out.