Tool post drilling in a small lathe

Batmanacw

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I have a Precision Matthew's 1030V. I recently watched Stephen Gotteswinter discussing drilling with the toolpost.

I had recently set up a nice rack full of mt2 tools to quick change in my tailstock.

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I decided I wanted to try tool post drilling and the pre-staged tools would be pretty handy for that. I bought a Shars MT2 qctp holder (250-105) to try out.

I dialed in the face of the holder with a top facing dti and dialed in the front opening and set zero on my cross slide.

I am stunned at how well it worked on mild steel and aluminum.

I didn't want to push it too hard in steel so I started with 1/4" and then step drilled to 3/8 and then 1/2". I used 0.0025" feed per revolution and 400 rpm. I'm positive I could have gone straight to 1/2".

Then I drilled 1/4" in aluminum and went straight to 3/4" mt 2 drill. I really could have gone to 0.005" feed. There is really no need push things because it's so fast and easy.

I broke a no 3 center drill on a chunk of mystery stainless. Way too much pressure needed to keep cutting. I'll stick with tailstock drilling for really tough materials.

I'm extremely pleased with the results so far. I'll get video tomorrow.
 
The one downside I run into with using the tool post to drill, is with longer MT drill bits I really need to use an indicator to square up the toolpost. My usual quick and dirty 1-2-3 block against the chuck doesn't quite square things up enough for long bits. Of course the multi-fix tool posts would solve that problem.
 
I did this video this morning. Hot rolled steel 1 1/8" diameter.


The hole will fit a 0.501- gauge pin but 0.502" won't start.

You can see the advantage of the mt2 and a bunch of pre-staged tools.

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Surface finish is pretty okay for hot roll and a drill.
 
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The one downside I run into with using the tool post to drill, is with longer MT drill bits I really need to use an indicator to square up the toolpost. My usual quick and dirty 1-2-3 block against the chuck doesn't quite square things up enough for long bits. Of course the multi-fix tool posts would solve that problem.
What I found works well is run the side of boring bar/drill holder up against the tailstock quill, that will get it close enough for most work.
 
I've got one of these, but haven't used it yet. The alignment pin looks like it'll make quick work of aligning the tool post/chuck, but without a DRO and tool offsets I'm usually setting things up with an indicator anyway.

 
What I found works well is run the side of boring bar/drill holder up against the tailstock quill, that will get it close enough for most work.
I just put the drill holder on the front of the tool post and run it against the body of the chuck and tighten the tool post bolt, to aligh with center, I use a center drill to tell me where the center of rotation is.
 
I have a toolpost-mounted drill chuck setup for my mini lathe. I use two lengths of 1/2" drill rod to align it, one in the lathe chuck and one in the drill chuck. To rotationally align I move the drill chuck-mounted rod so it overlaps the other one and advance the cross slide until they are exactly parallel, easy to do with a piece of paper underneath & adjusting until there's no light visible along the entire length of the overlap. Lock the tool holder down, then back off and align the (faced) ends until I can't feel a step going from one to the other. The vertical alignment is adjusted using a shim underneath the tool holder. A piece of printer paper is just right for my setup.

This approach is fast and easy. I keep the two drill rods in a separate box so they don't get dinged up or inadvertently used for some project.

When using the drill chuck I discovered an adjustment problem with the carriage slide plates because the drill chuck could cause the carriage to lift under the force of drilling. Normal turning forces the carriage downwards so I hadn't noticed the problem before using the drill chuck. This type of problem may not apply to all types of lathes but it's worth mentioning.

I also made a lock for the cross slide, just in case the drilling forces might move the carriage away from its on-axis location.

I don't recommend hand-feeding this setup when enlarging holes in brass (unless the drill bit is modified specifically for drilling brass). It will grab and self-feed before you can control it. In one instance I actually saw a drill bit try to "unwind" due to the force on the bit.
 
Okay guys, I am certain I am missing something here so an education is in order. I looked at one of the tool post chucks from edge technologies and thought, hum why would I use that when I have a tail stock to drill with? Could someone explain the advantage?
 
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