MadModder
Gallery, Projects and General => Neat Stuff => Topic started by: PekkaNF on July 07, 2014, 03:13:53 AM
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I have been been acutely aware of limitation of my tail stock. Found this one when I was googling around.
There are some systems to tow the tailstock with cross slide. This is new one to me:
http://www.swarfer.co.za/lathe/tailpow.php
Can't use it on my lathe, because the tail stock just does not have enough footing, but on Myford it apparently works.
Pekka
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If you are going to do that (http://www.swarfer.co.za/lathe/tailpow.php), why not just make a chuck or collet holder for your cross-slide (along with a center index pin set) and be done with it?
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Think its Smart and Brown that uses a simple towing latch on to tail stock base.
Far superior to above not only does it pull towards the base you don't have to faff about setting it up to use, dismantle put other toolpost back on, dismantle for next one and so on.
With that link it will be exerting a bit of lateral force, holes may not come out central.
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Jonny, seen couple of working examples on bigger lathes.
Lew, I have a MT2/1" adapter and QC block for tool holder. Tried it once and tool post had a tendency to rotate under load. The drill adapter was pretty far from tool post center bolt. I was thinking of aligning the whole thing, but there are pretty many things to align to the axis of the hole: Cross slide, tool post, QC holder (vertical and horizontal), adapter, drill...It's pretty easy to clock them straight, but to have them straight and centered? Need a method here, rather pleased if it does not start by chucking the piece I was turning out of the chuck and then chucking an mandrel the the adapter in the TP is aligned to....
I'm trying to figure out if it would be feasible to make a tail stock with fairly long stroke for drilling. Nothing "ultimate" just good enough.
Pekka
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That would be perfect for the deep hole drilling if you incorporated bearings making it a rotary chuck powered by a drill or pulley/belt/motor system.
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Pekka, my suggestion (without actually seeing your lathe or slides) is to use your slide but not your toolpost. If you can remove the toolpost, you can bolt down a block of metal on the slide in its place and drill it with a headstock driven drill.
First center drill, then drill into the block, driving the block onto the drills. This will drill on center for your lathe and parallel to the ways because the block is traveling with the carriage along the ways and the drill is at center height.
You can also finish bore it if you make a simple boring bar that runs between centers. The boring bar will insure that the hole is true to the lathe centers.
If you key the block to your slot in the carriage before drilling, it should be easy to replace it. The bored hole can be your bushing for a shaft. Put an internal taper in the end of the shaft to take your drill chuck adapter. The other end gets driven.
This shaft will always be at center height. You will just have to position the slide to center, and make sure it is square. It will be much more rigid than using the toolpost.
The above is the crude idea version -- you can do whatever refinements to it that make sense to you and suit your particular lathe.
Possible refinements:
Split bolted together block with shims for adjustment for wear. (Do this BEFORE drilling)
Relieve some of the internal bearing surface for less friction. (After drilling)
Or hole size to suit oilite or plain bronze bushings at either end -- split one side of the bushings for adjustment using a coping saw.
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.... If you can remove the toolpost, you can bolt down a block of metal on the slide in its place and drill it with a headstock driven drill.
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If you key the block to your slot in the carriage before drilling, it should be easy to replace it. The bored hole can be your bushing for a shaft. Put an internal taper in the end of the shaft to take your drill chuck adapter. The other end gets driven.
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Jeah..immolizing the cross slide and locating the drill holder is a key. You have done your Gingery-time. Haven't you?
Might go there...
Pekka
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You have done your Gingery-time. Haven't you?
Definitely!
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Another method, possible on some lathes, is to re-positon the tailstock in between the chuck and the cross slide.
Jack
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When towing the tail stock, how do you keep it tight down to the bed? If mine was not clamped tight down I'm pretty sure the nose would lift under load.