BXA tool holder for 1" shank tools ...

[wquiles]

I recently got a good deal on Ebay on a Dorian Knurling tool (cut style):

But of course, the problem is that the shank is 1". Normally with less expensive tools, I would simply mill the bottom of the tool, but this Dorian knurler retails for about $900, so I decided cutting the tool would not be a good idea.

I have a piece of 4140 steel that I bought to make a parting blade cutting block, so I decided to make a new tool holder for the Dorian knurler:

Here you can see two BXA holders to compare their relative sizes:

So to the bandsaw I went:

I cut the piece I needed for the Dorian holder, plus the pieces I needed for the cutting blade holder (to be done in a future post/project):

Piece on the far left will be used for some future holder. Middle two are for the cutting blade holder, rightmost piece if for this project (Dorian 1" BXA holder):

I took some measurements on a BXA holder, to duplicate those on my new one:

I first started by making all sides flat/parallel using my 1.5" face mill cutter:

But I did not like the "split" finish (I had to do two overlapping passes), but the mill was not trammed:

Of course, this project took a little deviation while I finished the VFD conversion (thanks again Barry!), so I started by tramming the mill:

I then aligned the vice using the fixed jaw as you guys recommended:

Once ready, I used my new 3" 45deg face mill to lightly re-cut the 4 sides (not the ends):

(by the way, this is why you NEED a NEMA 4 rated VFD!!!):

To my surprise, I did not get the twin-cuts typical of a mill that has been trammed. As you will see below, the mill "IS" trammed, but not with this cutter!:

Here I am using a 1" twin-insert cutter, and sure enough, you can see the double cuts indicating the mill is trammed. My guess something is not aligned quite right on the 3" face mill:

So I keep making 0.050" passes until I got to the desired depth:

I then took a 3/4" Cobalt 6 flute end mill to clean up the edges and bottom of the slot:

With this end mill, you can again see that the mill is in fact trammed properly - weird:

And of course, the Dorian tool holder fits:

Here on a "standard" 5/8" BXA holder for comparison:

So I then start making the dovetail, using my Dorian 3/4" dovetail cutter:

First I have to cut a slot to the right width, so I used again first my 1" two-insert end mill, and then clean up with the 3/4" cobalt end mill:

After each step, I cleaned up the edges with a file:

I am approaching cutting the dovetail very slowly: cut, test fit, cut, test fit, since I wanted a nice engagement. First cut was a tad small as I expected:

After a few more passes I had it all perfectly fitted:

The new mill with the VFD is a REAL JOY to use - hard to believe I waited this long to do the conversion. Now the mill is really easy to use!. Here I am drilling/tapping the holes for the tool holder set screws (3/8-16):

After using a file to clean the top (and bottom that faces the tool):

Another test fit:

As I expected, I had to cut a small relief on the bottom of the holder to allow enough travel to center the 1" Dorian tool, so here I am using my 1.5" end mill to take the 0.20" off:

Used a file to clean up the edges (no sharp corners anywhere!). By the way, I am using Brownells T-4 to "blue" the steel block - it looks really cool in person, almost like the case-hardened frame on a Ruger single action pistol:

Now it fits great:

And my first test of cutting knurling (just one pass, really light), on a 0.5" Al round stock before I went to bed last night:

I need to make another one of these 1" holders, but I think I will wait a little while - this was a LOT of work, but it turned out quite nice :twothumbs

Will

 

[precisionworks]

Wow, that is a lot of work, but the end result is awesome. No manufacturer makes a BXA block to hold a 1" shank tool, except W Quiles Mfg 😀

I did not get the twin-cuts typical of a mill that has been trammed. As you will see below, the mill "IS" trammed, but not with this cutter!

When you checked the head for tram, was the indicator swung 360 degrees, so that left to right tram could be checked, as well as front to back tram? I believe you did this already, so both left to right & front to back should be within .001" TIR.

My guess something is not aligned quite right on the 3" face mill

To check that, rest the face milling cutter with inserts (gently) on your granite surface plate & try to rock the cutter. With that many inserts it probably will not rock, so next try to get a .001" shim or feeler gage under each insert. My guess is that one insert is projecting farther than the others, which is not uncommon on a multi insert tool - but does need to be corrected or that one insert will do 90% of the cutting.

 

[wquiles]

Thanks Barry, although I don't think I will be trying to make these to sell - I would never charge enough to recover my time - here is a case in which a CNC machine would be nice to have :naughty:

As to tramming, yes, I checked all around. This picture in the groove shows cutting along the X axis, from left to right:

this picture shows the cutting along the y axis, front to back:

Both photos show nice, overlapping strokes from the 1" and the 3/4" milling bits, so I know the mill is trammed. However, something with the 3" is not right/aligned. I like your idea to check for the individual inserts, but I also wonder if perhaps this could be caused by the arbor and the shell not being perfectly aligned/parallel?

Will

 

[StrikerDown]

I'm NOT an expert in geometry but even when the tram is very close the spindle is still not a perfect 90 deg to the path of the table. Since the angle is not a perfect 90 at some point the farther away from the center line of the spindle the cutters will stop touching metal on one side of the circle.

Beautiful job and an excellent solution to the problem!

 

[gadget_lover]

I'd be willing to bet that the tram is not as good as it seems. The resaoning behind that statement becomes obvious when you think about the difference between the 3 inch mill and the 1 inch mill. The 3 inch has a wider sweep.

The 3 inch mill will exagerate any tram errors 3 times as much as a 1 inch mill. My math skills are not what what they should be, but I think that a .0006 deviation at 3 inches will be only .0002 at 1 inch. That might be less than the deflection of the tool and the work. Maybe that is why the smaller diameter end mill has the 'double cut'

I've found that I can get a real neat multipass overlapped finish using small end mills simply because that 'resets' the deviation every 1/2 inch.

BTW, good work on that tool holder. It looks quite profesional.

Daniel

 

[wquiles]

I'm NOT an expert in geometry but even when the tram is very close the spindle is still not a perfect 90 deg to the path of the table. Since the angle is not a perfect 90 at some point the farther away from the center line of the spindle the cutters will stop touching metal on one side of the circle.

Beautiful job and an excellent solution to the problem!

I'd be willing to bet that the tram is not as good as it seems. The resaoning behind that statement becomes obvious when you think about the difference between the 3 inch mill and the 1 inch mill. The 3 inch has a wider sweep.

The 3 inch mill will exagerate any tram errors 3 times as much as a 1 inch mill. My math skills are not what what they should be, but I think that a .0006 deviation at 3 inches will be only .0002 at 1 inch. That might be less than the deflection of the tool and the work. Maybe that is why the smaller diameter end mill has the 'double cut'

I've found that I can get a real neat multipass overlapped finish using small end mills simply because that 'resets' the deviation every 1/2 inch.

BTW, good work on that tool holder. It looks quite profesional.

Daniel

Thank you guys 😱


And by the way, I think that what you guys are saying does makes sense - the diameter difference might be exposing a less than perfect tram situation. That would explain why the 3" does not cut as well as the 1" and 3/4" mills. I guess I will have another go at it and see if I can get even closer results. Thanks :thumbsup:

 

[StrikerDown]

I was chasing the tram on my RF 31 but it is an elusive beast. I can adjust the tram then raise the head to make a cut and the tram is off!

It's sometimes hard to accept less than perfection but I don't want to go crazy... at least not for a little while!

You got the job done, it looks great and if it works half as good as it looks it's a success!

Wish those were available!

 

[darkzero]

Man you make it look so "easy" but of course it must have been a load of work! Not to mention the thousands of dollars spent on equipment & tooling for you to be able to even make that. How long did it actually take? Very nice work indeed! :thumbsup:

We need to see some awesome knurling now!

 

[bluwolf]

Beautiful piece of work Will. I'm curious how long it took you to make it also. And how much time does it take you to document it with all the terrific photography?

Mike

 

[precisionworks]

I'd be willing to bet that the tram is not as good as it seems.

+1

Your photo shows the Indicol almost vertical, which means that the dial test indicator sweeps a small circle. A better way to read deviation is to lower the spindle closer to the table & extend the Indicol horizontally as far as it will reach - about 6" on both left & right. If you are really OCD, use an extension rod and go out 12" left & right. You'll be surprised at how far out the head is.

I believe that nod on that mill is adjusted with shimming.

 

[unterhausen]

You got the job done, it looks great and if it works half as good as it looks it's a success!

Wish those were available!

Yeah, it's frustrating that you can't buy a larger tool holder. Go into just about any shop and you'll find a batch of butchered holders.

 

[darkzero]

Yeah, it's frustrating that you can't buy a larger tool holder. Go into just about any shop and you'll find a batch of butchered holders.

Well Dorian, Aloris, & DTM do make oversized holders, 5/8" for AXA, & 3/4" for BXA but they're around $75+ ea. Milling a BXA oversized holder probably wouldn't end up being as beefy as Will's is.

Judging by the sizes that Dorian makes these knurlers in, do cut knurlers require even more force than the conventional forming knurling tools?

 

[wquiles]

Barry - I will do the tramming further out next time - thanks.


Guys, I honestly did not keep a log of hours spent - needless to say it was a LONG time over several days, trying to balance hobby/family. I do wish there was a way to buy these already made, as this 1" holder will accept any of the 3/4" shank tools as well - and there is plenty of 3/4" and 1" shank lathe tools cheap on Ebay.


How well does the Dorian cut knurler works? I am just trying to get familiar with it, but it looks very promising so far. As I need a knurled wheel for adjusting height in this holder, I decided that will be the first real use, even if it does sound like a catch-22.

I took a 3/4" dia Al stock, and cleaned the outside surface:

Did one pass with the knurler, at about .006" or so - feed it like if I was threading at 20TPI:

Drill:

Tap:

Cut bevel on each side:

and part both off-sections:

It is not "pretty", and the knurler was not "exactly" on center, but it works well:

Clean up cut-off edge:

Clean up threads:

Installed in place:

Will

 

[PhotonFanatic]

Will,

You are being way too timid with the infeed--you need to jam the knurling tool into the piece so that a complete knurl is being formed, i.e., with real sharp points, then traverse along the axis of the piece.

In AL, even if things go awry, the worse thing that might happen is some slight twisting to the knurling pattern.

That's a gorgeous tool holder--I'm jealous.

And to answer darkzero's question: No, cut knurling does not require more force (pressure) than conventional form knurlers. In fact, they are less stressful to the lathe's spindle--it is cutting the material, not deforming it.

 

[darkzero]

Thanks Fred.

Will, is that the pattern the knurl is supposed to look like (looks odd)? Also how fast was the spindle speed? Hurry up & practice, I want to see what that thing can really do! 🙂

The coarse knurl on my hammer handle was done at 0.025" infeed & 0.030" carriage feed at about 60 rpm on a conventional knurler (this is also what my book references too. Funny my book shows an example of a cut knurler & it shows your same Dorian knurler). Playing around 0.015 - 0.020" gave a better looking knurl in my opinion using the old cheap knurlers they had. I tried to do that on my 8x14 & lets just say I'll never try that again, thought I was going to break something. :laughing:



These are the only two types of knurling that looked half decent that I have been able to do with the 8x14 but using the cheap tool that came with the TP set. But I cheated, I took a pass over the knurl. As I was told, the quality of the wheel is very important.

 

[precisionworks]

You are being way too timid with the infeed--you need to jam the knurling tool into the piece so that a complete knurl is being formed

+1

Quite a bit of info on the web, here's one:

http://www.accu-trak.com/holders_cuttype.html

 

[darkzero]

On Will's knurler, what does the adjuster on top adjust? Centering the wheels to the workpiece?

 

[wquiles]

You are being way too timid with the infeed--you need to jam the knurling tool into the piece so that a complete knurl is being formed, i.e., with real sharp points, then traverse along the axis of the piece.

Thanks Fred. I will try tomorrow with another test piece and do a much deeper cut. Do you support the material being knurled with the tailstock while you do knurling?

Will, is that the pattern the knurl is supposed to look like (looks odd)? Also how fast was the spindle speed? Hurry up & practice, I want to see what that thing can really do! 🙂

The wheels that come with the knurler are for a diamond pattern (if I recall correctly). It should look odd since I don't quite yet know what I am doing, but I hope to eventually get better at it.

Spindle speed was 60 RPM, same I do for threading. I have not tried using the power feed, so I just used the same threading power feed I used for the Mag 1xD's at 20TPI.

The coarse knurl on my hammer handle was done at 0.025" infeed & 0.030" carriage feed at about 60 rpm on a conventional knurler. Playing around 0.015 - 0.020" gave a better looking knurl in my opinion using the old cheap knurlers they had. I tried to do that on my 8x14 & lets just say I'll never try that again, thought I was going to break something. :laughing:

Ahh - that is quite a bit deeper cutting than I tried!. No wonder it was shallow cutting at .006". Did you do a single pass at .025" infeed? All of that at once? Didn't the piece deflect under that much pressure, or was it supported by the tailstock?

 

[wquiles]

On Will's knurler, what does the adjuster on top adjust? Centering the wheels to the workpiece?

Yup, it allows fine-tunning the wheels to the workpiece.

 

[StrikerDown]

I think I would be just a bit timid the first time using a tool costing almost a grand! Even if I bought it off of ebay for less:sweat: