Compound mounted drill adapter???

I'm curious about using the compound rest for most drilling operations as opposed to the tailstock. The TS on my lathe does not work worth a turd for drilling. Even with a good center punch my center drills always wander around a bit when they start. I know this is likely due to wear on/in the TS and I know there are ways to work around this problem. My question is more about using the compound for drilling for the purpose of affording more travel and easier chip clearing.
If I remove my QCTP and make a drill adapter to sit on, and clamp tightly to, the compound rest would this be something others are also doing? I am wondering if those that may can offer their experience in making such an adapter for drilling.
BTW - I have 3c colletes up to 1/2" from a vertical attachment I have for a horizontal mill. I can also use the 3c sleeve draw tube from this attachment and use it in some sort of block mounted on the compound rest. I am curious about using these items in such an adapter??? . Is making a 3c collet holding system just a dumb idea?
Thanks!

They make quick change Aloris type toolholders with a chuck, you know.
Dovetail Chuck Holder CXA-35

metalmagpie

Having the collect drill holder dead center to the chuck or part may be a problem. Problem could be off center drill point part not center if chuck (wobble) or tail high or low.. I commonly tool bit cut a drill start to indicated part if I have to be dead center with a drill.
[Is making a 3c collet holding system just a dumb idea?]
like the one metal shows with a vertical adjustment is a good idea.

A misalignment in the machine will cause the problem you've described...

A QC drill holder is very easy to use and recommended...

I don't know your lathe, but my tail stock also is not the sturdiest. And aligning a tool post mounted drill will also be somewhat difficult.

I suggest:

1. Carefully align your tail stock. This should not be overly difficult and should be done anyway.

2. Get a spotting drill, preferably a carbide one, and start the hole with that. Or do as Michiganbuck suggests and make a starting dimple with a lathe tool.

3. Use machine tool length drills whenever possible.

Those three steps work OK for me. Even with a less than solid tail stock, I can always make a well centered hole. The idea of using a spotting drill, which is real short, is that it will not flex much and even if it is off center, the hole will be well centered.

It may be counterintuitive, but it doesn't take all that much prep to drill using the carriage, provided the part to be drilled is sturdy and chucked short in a chuck with jaws in good condition.

I'd recommend using a spot drill unless you are drilling a center hole, then, just use a center drill. Start up the lathe, and face the end of the part at least for a diameter as large as the hole to be drilled. This is an absolute requirement, if the face is wobbling, the drill will be deflected.

Bring the spot drill up to the spinning work. Eyeball it close to center, not necessarily right on, off the bat, and just lightly touch the point and allow a light circle to scribe on the end of the work. Back off and now adjust the tool point to the center of this circle. Use the height adjustment of your quickchange holder to get the tip at the right height. There is not a lot of leeway with the height, because there is not much 'float' of the cross slide in the vertical (except for the clearance of the hold down strips under the bedways). Then center the tool tip crosswise fairly close.

Now begin to drill the spot. The tool may smoosh around a little bit, but if it is already very close, it will gyrate right to center of the spinning axis. The slop in the cross slide will probably allow it to move. If the tool is too far off axis, it will get thrown away if it cannot self center. After you see a good round spot has formed on center, then change the tool and drill the hole.

Tail stocks are for holding centers. Drilling with most tail stocks sucks shit.

Rig up a thing on your carriage or use a tool post drill chuck.

Thanks all. Yes I am aware that drill chuck tool holders are available for Dove tail QCTP. The cost of these seems high Co sideline anyone that needs such a tool holder likely has the ability to make one in an hour or two??? Still I understand why many would purchase I stead of create.
I have spent literally days tweaking my lathe, levelling, checking, aligning, turning test bars etc etc and it is as close as I can make it. I've followed the advice here in this effort and I'm confident the drilling, especially the starting, is difficult due to a slightly worn tailstock. Even if the tailstock was giving me good starts there is still the issue of having to run the handheld in/out constantly when drilling holes deeper than 1/2-1". It would be good for quick center drilling and this may be the most drilled hole?
I will continue to look at the tool holder options for a drill chuck. Initially I thought removing the chuck from a drilling equation would remove a variable but, as others have said, the drill will right itself if done properly.
Thanks again

An alternative to the QC drill chuck block is the QC 5C block. I use the latter when I want to drill from the compound.

Try this: If the drill wanders even after starting from a center drill.

Socket the drill so the cutting edge lie on a 20 - 30 degree clockwise slope to horizontal. This gives the tool access to touch the drill's flute relief with the tool.

Start to drill but before the start enlarges to the lip, run the tool in to just touch the drill. If the drill doesn't steady, deflect the drill a trifle with the tool and slowly back off as you feed the drill. This forces the drill to start concentric. But remember, you have to do this at the very start .

If the tool is delicate, use the back end of a boring bar - anything to provide a momentary touch to steady the drilll.

You noobs reading in, remember that drills are not real precision hole-makers. They drill oversize and wander a bit even under ideal conditions. If you need and accurately sized hole or one that;s precisely located - or both - subsequent operations like boring or reaming maybe required. .

All that said, if your tailstock is in poor condition you may still have troubles. There has been much written in this forum on how to doctor ailing tailstocks, Do some research here and on the machine rebuildng forum.

Also the compound carriage etc may not have enough thrust to feed a larger drill from the solid. Some of us older farts have wrist troubles or arthritis that limit the vigor we can impose on the tailstock handwheel. The tailstock is robust, built to be used for feeding drills, far more so than the carriage or compound slide.

I solved it by grafting on an 12" aluminum trick wheel intended for a fishing boat remote steering station. You can also add a small worm drive power feed or a servo feed for a turret mill to drive the tailstock handwheel. . Mods and adaptations may require an out of the box thinking process for a successful conversion. Do your math so feeds and ratios work out for the drills you typically use

That is a good tip, Forrest. Especially useful if trying to redrill damaged center holes, too. That last couple of thou of runout of a center drill is imperceptible to the eye, and one might spend a lot of extra time boring a damaged center when you can quickly bring it into wack with the 'steady the drill' technique you described. I'll often use the blade of my cutoff tool to steady the tool, just lift the toolblock a half inch high on the toolpost so I can use the lower face of the blade as a contact point.

also think about where you want your work centered, at the jaws or further out.

and forrest: i dont agree. a properly mounted drill will drill undersize.

dian said:

a properly mounted drill will drill undersize.

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Never seen that, dian. Oversized, yes. Crappy interior finish, yes, Lobed, yes. Undersized? Not unless the drill was mismarked with the wrong size.

dian said:

also think about where you want your work centered, at the jaws or further out.

and forrest: i dont agree. a properly mounted drill will drill undersize.

Click to expand...

please educate me on that one

sfriedberg said:

An alternative to the QC drill chuck block is the QC 5C block. I use the latter when I want to drill from the compound.

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I use mine in the KDK 5C block. So you don't have to have an Aloris...

i have made a similar tool - a block of steel , bolted to the compound with a drill chuck for carriage drilling .
i used a 3/4 straight shank arbor with a 5/8 drill chuck .

bolted the block to the tee slot , started hole with a #6 center drill in the 3-jaw , then drilled and bored to .010 under, then reamed @ .750 . i used an offset boring head to make the hole straight , but a small boring bar in a
4-jaw would be equally as good . the block also has a .500 hole for S+D drills . both have top and side set screws .

to align the thing , i put a dowel pin in the chuck , indicate straight w/ the ways , then put an indicator in the chuck to get it on center . takes 2-3 minutes.

tnmgcarbide said:

i have made a similar tool - a block of steel , bolted to the compound with a drill chuck for carriage drilling .
i used a 3/4 straight shank arbor with a 5/8 drill chuck .

bolted the block to the tee slot , started hole with a #6 center drill in the 3-jaw , then drilled and bored to .010 under, then reamed @ .750 . i used an offset boring head to make the hole straight , but a small boring bar in a
4-jaw would be equally as good . the block also has a .500 hole for S+D drills . both have top and side set screws .

to align the thing , i put a dowel pin in the chuck , indicate straight w/ the ways , then put an indicator in the chuck to get it on center . takes 2-3 minutes.

Click to expand...

This is nearly identical to the method I was considering. I realize this won't mean drilling with the lathe will give a high tolerance result and that more precise operations will be needed for such.
Many thanks.

I have a chuck mounted on a QCTP holder and I do like the auto feed feature but it has distinct disadvantages. One is that if you don't pay attention and clear the swarf you risk snapping off a drill in the work piece. On a deep hole I think it is much safer to use the hand wheel on the tail stock and clear the swarf often. The other thing is that if you use the QCTP for chucking the bit you lose the ability to to use the cross slide to steady the bit. I very often use the back side of a cutoff blade holder to steady the bit. I think Forrest mentioned this but not in detail. Before I started using a QCTP I often used the back side of an Armstrong style holder to stop a bit from walking around and the cuttoff blade holder is the closest thing that I have now for doing this. You just gently touch the flutes of the drill until it stops moving around and then it will generally steady itself. If not then another gentle touch on the next flute in line will steady it.

Thanks. I've tried this but never was able to get it right. Time to give this another look.

janvanruth said:

please educate me on that one

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well, the only thing i can say, that if you start the hole properly and have a good setup and a good drill, the hole will be smaller than the drill size. it happens to me quite often. here i was drilling 6.0 mm, i believe and a h7 pin didnt go in. i had to lap the hole a little.