Question on Drilling with G0602 lathe

[kizmit99]

Hi all, I have what is probably a very stupid question...

I'm trying to drill a 1/2" hole 2.2" deep into a 3/4" piece of Drill Rod. I have a chuck mounted in my tail-stock, and the tail-stock can be cranked out about a 2.5" (so it would seem to be easy); however, the stock needs to be extended about an 1.2" for the taper on the chuck to engage. If I screw it back any further the tail on the taper bottoms out then the chuck and taper push out. So, it seems I can only drill a hole about an inch in depth... Here's a picture of what I've got:



What am I missing? Can I only drill holes about an inch deep?
The taper adapter the chuck is mounted to has a "tab" on the end of it - should I consider cutting that off so that the tail can be 'pulled' further in before bottoming out and disengaging? I feel like it must be something very simple I'm missing -- how do I use the lathe to drill a hole deeper than about an inch?

Thanks!

 

[Ray C]

Just for clarity and edification, the round tube that receives the MT taper is called the "ram".

Anyhow, am I to understand the total ram travel is 2.5"? If that's the case, you'll need to drill a partial depth then, retract the ram then, unlock the tailstock from the bed and manually move it forward and cut another 1/2". As the bit starts getting embedded, you'll have to keep unlocking the tailstock to clear the chips. Don't let chips get too packed-up in there or, it will do two things: 1) Generate a boatload of heat -hot enough to either temper or work-harden your tool steel. 2) Break the bit.

You could grind the tab off the end of the MT taper and get a little more travel... If you that route, don't overheat the daylights as you grind it off or, you'll stand a chance of tempering the tapered part. -Probably not the end of the world if that happens though. Keep some water handy, grind until its just about to get uncomfortably warm to the touch then cool it off. That will safely keep it out of the martenizing zone of the metal.

What kind of tool steel are you working on and what condition (hard, annealed etc) is it currently in?

Ray

 

[epanzella]

Somewhere in my surfing I saw a post in which a guy used a door hinge and a dowel to connect his tailstock to his carriage. One so connected, you could use power longitudinal feed or the carriage handwheel to give you the travel you need.
Ed P

 

[kizmit99]

Just for clarity and edification, the round tube that receives the MT taper is called the "ram".

Anyhow, am I to understand the total ram travel is 2.5"? If that's the case, you'll need to drill a partial depth then, retract the ram then, unlock the tailstock from the bed and manually move it forward and cut another 1/2". As the bit starts getting embedded, you'll have to keep unlocking the tailstock to clear the chips. Don't let chips get too packed-up in there or, it will do two things: 1) Generate a boatload of heat -hot enough to either temper or work-harden your tool steel. 2) Break the bit.

You could grind the tab off the end of the MT taper and get a little more travel... If you that route, don't overheat the daylights as you grind it off or, you'll stand a chance of tempering the tapered part. -Probably not the end of the world if that happens though. Keep some water handy, grind until its just about to get uncomfortably warm to the touch then cool it off. That will safely keep it out of the martenizing zone of the metal.

What kind of tool steel are you working on and what condition (hard, annealed etc) is it currently in?

Ray

"ram" - got it, thanks!

Yes, the total travel on the ram is about 2.5", but 1.2" is 'used up' by the overall length of the MT3-JT33 taper the chuck is mounted on. Leaving me only about 1.3" of usable ram travel... The taper I have is one of these from Grizzly:

I don't *think* the tab on the end of the MT3 taper is needed for anything (but that's just an assumption on my part). Given that the cost of this is only about $12 I'm not too worried about destroying it, but I only want to try cutting it shorter if folks think that would help... I think the tab itself is about 5/8" long - would removing an additional 3/8" of the end of the taper itself be a bad idea? Seems to me like that wouldn't weaken the taper grip too much (but again, I have zero experience to base this on).

If I were to go the "unlock the tailstock and slide it forward" route would I stop the spindle first or do that with spindle in motion? I see the possibility of bad things happening either way...

The rod is O1 3/4" drill rod from enco: http://www.use-enco.com/CGI/INPDFF?PMPAGE=899&PMITEM=422-1328
I've done nothing to it but cut to length and clean up the ends with a carbide cutter. It seems to machine ok...

Thanks for the input!
--Ralph

 

[kizmit99]

Think I just found the answer to my question about cutting more than just the tab off... Found this:

at this site: http://crevicereamer.com/Page_88.html

Looks like this is probably the route I'll take...
--Ralph

 

[jamie76x]

Warning! If you cut the taper off too short if will not be able to pop itself out when you retract the ram. try taking the flat tang most of the way off first and see how it works, then take off just enough so you can get back to "0" without the chuck popping out

 

[Ian Bee]

Think I just found the answer to my question about cutting more than just the tab off... Found this:
View attachment 56128
at this site: http://crevicereamer.com/Page_88.html

Looks like this is probably the route I'll take...
--Ralph

Nup...

I had to spend a whole heap of cash, getting my tailstock re-machined, because the MT spun around, and chewed it all up. Had new dowel pins put in, nice now, but hell, it cost me!

Just do as others, and I do, wind it in, wind it back, slide the tailstock forward, wind it in, pull it right out to clear chips, and so on.

 

[Codered741]

Most likely the tail stock takes an MT2 short taper. You really have three options, two of which have been mentioned.

1. Trim the tang, and taper down to the correct length. Make a mark on the shank of the taper, fully seated, then back the ram in to 0. Another mark, and measure. That is how much you need to remove, and still be able to eject the shank. The worst thing that happens is you trim it too short, and have to add material back, or buy a new shank.

2. Live with what you have. Obviously not ideal, but it will work, you will just need to do some extra steps while drilling.

3. Get an"short" MT2 arbor. Basically #1, but no chance of screwing up.

I had the same problem on my mini lathe. I turned the shank of my MT2 arbors down on the ones that came with my mini lathe. They were not hardened, and were very easy to shave down a bit. I simply chucked the drill chuck, the static part not the locking collar, and took a little off, then test fit. I also had a short MT2 on the live center for reference.

Good luck!

-Cody

EDIT: FYI. The tang at the end of the taper is a safety which keeps the shank from rotating in the ram, in case the taper gets dislodged, or was not seated correctly. The morse taper is classified as a self holding taper, and from experience, when properly seated are very difficult to twist out. Not saying that it does not, or cannot happen, but difficult when properly seated. Give the tool a tap (a TAP, don't whack it with your 5# maul) with a dead blow hammer to seat it firmly into the ram. And make sure that the shank and ram are both free of swarf and other debris before seating it.

 

[kizmit99]

Warning! If you cut the taper off too short if will not be able to pop itself out when you retract the ram. try taking the flat tang most of the way off first and see how it works, then take off just enough so you can get back to "0" without the chuck popping out

Yep - aware of that. But, seriously, thanks for mentioning it. While I was aware of that bit, there could be other bits of info just as "obvious" that I may have been blissfully ignoring. At this point I'm really at the "don't know what I don't know" stage...

Most likely the tail stock takes an MT2 short taper...

Hmm... All the documentation on the lathe refers to these as "MS2" and my google searches never stumbled across the concept of a "Short" MT, just folks speculating that the Chinese marked them in a non-standard way. It makes much more sense that MS2 would refer to a Short MT2!

FYI. The tang at the end of the taper is a safety which keeps the shank from rotating in the ram, in case the taper gets dislodged, or was not seated correctly.

That was my understanding as well. But since the ram doesn't seem to have a space for the tang to engage I figure it shouldn't hurt anything to remove it...

I had to spend a whole heap of cash, getting my tailstock re-machined, because the MT spun around, and chewed it all up. Had new dowel pins put in, nice now, but hell, it cost me!

I'm quite curious about your experience... Was that with a shortened taper? If so, was it shorted a significant amount, or was it just the tang removed? I would be planning on dressing the cut end of the taper (not like shown in the picture I included above). I could see where spinning it with a sharp edge or burr could cause damage, but with the edge broken with a radius and 'polished' I wouldn't expect it to grab and dig in (any worse than if the full size taper spun). I expect that shortening the taper would reduce the 'gripping' strength of the taper, but if shorted only slightly I wouldn't expect that much loss of strength... especially if it's actually a Short MT2 and all that would be happening is the regular MT2 would be being machined down to the length of the Short MT2.

Just do as others, and I do, wind it in, wind it back, slide the tailstock forward, wind it in, pull it right out to clear chips, and so on.

When doing this do you just leave the spindle spinning? Once I unlock my tailstock it seems like there's a fairly large amount of play in it. I'm a little concerned that once loose it would cock and jam up... Am I being overly concerned?

Thanks for everyone's input!
--Ralph

 

[Ray C]

Here's a set of Morse taper reamers. One is for rough cutting and the other is fine finish. Available on eBay. These are MT3 and were about 39 bucks for the set. If you should get swarf in the ram and it scores things up (it happens), stick a taper reamer in there with some cutting oil and give it a couple spins with a wrench. Wouldn't hurt to use a point in the chuck to hold it straight. It will remove any ridges and if there are grooves, just leave them alone -it won't really harm anything. Do your best to remove any ridges from the taper insert tool. Modern lathes have hardened ram tubes (mine is RC 50) so don't waste your time trying to dig-in to remove grooves. The taper cutters are no doubt harder and capable of cutting RC 50 but you'll probably do more harm than good...

PS: One of the reasons I'm making a turret tailstock (See thread called "Mystery Project") is cut-down on the amount of removing/inserting different taper tools. Slows you down and eventually you'll get some swarf in the tube and score things up....




Ray