Tuesday, November 16, 2010

Milling Squarely

A customer was having problems milling parallel and square surfaces using the Taig milling attachment. It’s been a while since I used the milling attachment as I have the Taig mills, but the principles are the same for big and small mills. Anyway, I quickly (hence some blurry pics) put together this post to show what I achieved. I'll put up a better guide later on Cartertools.com later.


Setting up the milling attachment square is a bit of a chore. First, move up the quick alignment fence of the milling attachment. It’s fine for rough work but gets in the way here.


With a good parallel in the vise indicate it square along the axis of the cross slide travel, twisting the milling attachment as needed to get a consistent reading over the travel of the cross slide.


This is a basic setup.


I always tap the work down in the vise with a deadblow hammer. Note that this can cause misalignment if something slips...


And tighten up the jaw screw after getting it snug. This also can have unexpected effects on squareness though.




Testing for parallel after milling both ends. .209” on one end.


.203” on the other. Not so good.


Raising the work off the bed with a dowel pin.


Milling again.




.200”, so good within a couple of thou. I could have done better, later…


Using some toolbits as parallels to raise up the block. It's important to check that they are the same size.






.5062”, so about .0035” off from the unmilled surface.


Flipped and milling the other side.




.5007”, so about .0035” off again.


Well that’s not terrible for rough work, but I’d like to get within a thou’. So I mounted another parallel and checked back and forth in the two planes.


Off about .007”, not good.


The bed was parallel though.


I checked the jaw.


Way off. So I removed the fixed jaw, cleaned it, aligned it as best I could without the steel jaw attached, cleaned oil and such off the steel jaw and replaced it, Basically making sure that the fixed jaw, which is the primary reference, was square. Remove any burrs and lapping may help. This isn't a precision vise compared to a toolmakers vise or a Kurt vise though.



Testing after replacing and it’s dead on except at the very bottom where the steel is slightly deformed. I could remove this by filing/lapping.


Since the edges aren’t square (remember they’re a few thou’ off.) I used a dowel pin between the moving jaw and the work. This rolls between the moving jaw and the work as it’s tightened, keeping the work from moving at all in relation to the fixed jaw.


Here’s another shot.


.04869” at one end.


.04864” at the other. About .0006" off.


One spot, where the end mill raised a burr is .4876”, it’s important not to be misled by an artifact like this.

Anyway, the lessons are to check the setup of the vise, make sure the fixed jaw and bed are square to each other and that all travels are square/parallel. Use a dowel pin between the moving jaw and the work to keep the force of clamping from misaligning the work. Hope this helps. There are a bunch of other tricks that can achieve the same ends.

Tuesday, October 26, 2010

Using The Taig Lathe As A Cutoff Saw.

A customer prompted me to try something out, using the Taig as a cutoff saw. He needed thin pieces cut from round and square rod. While parting tool would certainly work, the saw allows a thinner cut, especially if you source one from MSC, etc. that is thinner than the stock Taig saw, as well as a truly flat cut where a parting tool can flex a bit if you’re not careful. When setting up the saw and when clamping the work always unplug the motor, the last thing you want is the saw spinning around while your hand is around it.


Unfortunately I didn’t have the Taig 1110 on hand, so I had to use the ER Spindle adapter to chuck a home made saw arbor in the lathe, but the idea is the same. The Vise is mounted directly to the cross slide. I show the 2225 rather than the 1225, but the 1225 is probably what a lathe user has, and will work the same.


I bent up some 3/16” steel rod to make a stop for the work.


An overall view.The carriage is locked. It pays to take the time to align the vise square with the cross slide travel.


Cutting off.


A thin disk cut off.


When clamping work in the vise I move the jaw so that it’s snug, tighten down the moving jaw top screw, then tighten up the clamp screw. Again it’s important that the work be resting square along the bottom of the vise.

Friday, September 24, 2010

A Few Links

Here are a few Taig and Machining related links:

Thursday, September 23, 2010

Steve Fornelius’ Steady Rest

Steve Fornelius says, "I needed a following rest for my lathe and after a basically fruitless search, I decided to heavily modify on by JR Bentley.
I had to make it simple, because I don't have a mill to make anything fancy! If you can tell me how to post to your site, I'll submit there.
Anyway, here's the gist of the project:
One piece 3/4" x 1/2" four inches long for the base
One piece 3/4" x 1/2" fly cut to 1/2" x 1/2" x 3 inches long for the crosspiece
Two pieces 3/4" x 1/2" fly cut to 1/2" x 1/2" x 2 inches long for the upright and guide support
Two pieces of 1/4" brass rod for guides
Five 3/4 inch 10-32 socket head cap screws
Simple drilling, tapping and counterboring for the cap head screws. I found I could use my Delta 9" bandsaw to cut the metal, so I saved a lot of hacksawing!

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Wednesday, September 22, 2010

John Silvia’s Quick Change Tool Post


This is my version of the quick change tool post by E. Paul Alciatore III as published in the Feburary/March 2010 Machinist's Workshop magazine. I modified his design to hold 1/4" tools and to fit the taig. Instead of using steel for the tool holders, I substituted aluminum. I figured if it was strong enough for the original tool holder it would be fine for this one. As long as I was using aluminum I thought it would be fun to try anodizing, hence the red color.
I made the tool post out of 3/4" drill rod. I also used a piece of the drill rod to make a D-reamer to size the hole in the holders. On the bottom of the post I milled flats to match a 5/8" square hole in the mounting plate. The mounting plate was made of 1/4" steel. Mounting the post to the plate made it easy to mill the large flat on the post at 45 degrees. The large flat is 5/8" from the other side. The combination of mounting plate and post can be mounted on either the left or right side of the taig cross slide and, because of the square hole, it can oriented to cut on the left or right. The base of the post does not come all the way through. When tightened down with the two bolts, believe me, this post is going nowhere! Of course, by using only the bolt through the post it can be used at any angle.
The tool holders are 1 3/4" on a side and 1 1/16" thick. When cutting the corner off the tool holder the side with the fixed bolts needs to be flush with the D-post. The other side is milled 2-3 thousands deeper to allow tightening. I'm ashamed of the knobs, but at $2.50 for 10, they were too cheap to pass up and are easily strong enough.
Mr Alciatore came up with a great design! It is easy and cheap to make. It took me about 1 day to make the first tool holder, but less than two days to make the next 9. It is a lot easier to do them in batches.

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Sunday, September 12, 2010

A Plumbing Adapter

The faucet for our water filter broke and the new one had different plumbing than the old one. Rather than redo all the connections I made an adapter to go from the faucet (7/16”-24 UNF for a 1/4” compression fitting) to the tubing (3/8” compression fitting)


A piece of “medical grade” Pomalux Acetal Copolymer.


Center drilling


Drilling for the tap.


Tapping (under hand power…)


Drilling the rest of the way through 1/4”


Flipped in the chuck and turned down to 3/8” diameter for the compression fitting.


Milling a hex so I can get a wrench on it.


The finished adapter.


In place under the sink.


The new faucet on the sink. The picture makes me think I need to tear apart the whole kitchen counter.

Anyway, no need to drive to the hardware store, although I was lucky (or a good hoarder) to have the 7/16”-24 tpi tap on hand. It isn’t common.