AXA Tool Holder(s)

[PeterT]

Oh, then you are practically home free ! LOL

Another thing that might be messing you up, see how @eotrfish shows the relief step on the back surface. Your dowel must be tangent to the actual dovetail surface like his circles. If you used too big a dowel diameter (red circle) resting on on the relief surface, then the inter-dowel distance measurement will be erroneous. Same thing for measuring/duplicating the dovetail depth. It must be from face of dovetail to arrow surface, not the relief. Something like a vernier probably is error prone because there may not be much surface to contact. Best if you can lay in a block of known thickness across the flats & measure distance with a depth mic.

 

[Susquatch]

I can't take credit for it. Paul Edwards, a journeyman Patternmaker/Toolmaker I used to work with used to say it a lot. Great man, who taught me a lot.

Perfection is an insult to the gods is a good one too. Perfection is the enemy of completion is one that creeps into my projects all to often, and a constant struggle......

I need to make some of these into signs for the shop to remind myself sometimes lol

Here is a varient of that one that I personally like:

"Never let the perfect be the enemy of the good."

 

[YYCHM]

Not sure this proves anything but I thought I'd try it.....

I'm seeing a half thou discrepancy traversing from the top of the dove tail to the bottom. There's only a 1/4" of dove tail flat in there.

 

[Darren]

Thats a wee bit much. Since you already have the indicator set up, should be able to make it zero fairly easy. is the gib snug?

 

[YYCHM]

Thats a wee bit much. Since you already have the indicator set up, should be able to make it zero fairly easy. is the gib snug?

By 1/2 thou I mean 0.0005" is that 1/2 thou? I think I might end up chasing my tail if I try and get it any closer. The indicator starts at 0 then jumps to 1/2 thou at 1/4 span, returns to 0 at 1/2 span and ends up 1/2 thou at full span. Does the same routine when backing out. Flaws in the face maybe?

This is the steel holder. Looks pretty darn close to me and they all lock up solid from what I can tell.

 

[thestelster]

Thought had crossed my mind all ready. Something else that occurred to me is that I need to devise a method of checking that the shaper head down feed is actually tracking 30 deg. So far I have assumed the angle graduations on the head swivel were accurate.

You need to stick a sine bar in there at the 30degrees. Attach your DTI onto the tool head with the probe on the sine bar. As you advance the tool head the indicator should read zero the whole length of the sine bar, if not, adjust the tool head until it does.

 

[PeterT]

And even with 0.0000" DTI runout, your steel blank might be stress relieving once a big asymmetrical notch has been removed from one side.
My China block surfaces look ground, maybe semi hardened? ** meant to add, maybe heat normalized as part of process**

 

[thestelster]

And even with 0.0000" DTI runout, your steel blank might be stress relieving once a big asymmetrical notch has been removed from one side.
My China block surfaces look ground, maybe semi hardened?

I agree. Never use cold rolled steel unless you are machining rounds on the lathe, or drilling right through on plate. I remember years ago I need to machine .040" off the top of a 1/4" thick by 1/2" wide piece of cold rolled, when I took it out of the milling machine vice, it looked more like a banana! I use hot rolled steel, or prehardened tool steel for anything intricate. I've never used Stressproof, but I understand that would work as well.

 

[PeterT]

I've used (turned) 1144 SP (Stressproof), it's nice, but I've only seen available in round.
I've wondered what would be comparable alloy in chunky rectangular stock, any recommendations?

 

[thestelster]

I've used (turned) 1144 SP (Stressproof), it's nice, but I've only seen available in round.
I've wondered what would be comparable alloy in chunky rectangular stock, any recommendations?

I've used quite a bit of Uddelholm Impax Supreme: https://www.uddeholm.com/app/uploads/sites/44/2018/08/Tech-Uddeholm-Impax-Supreme-EN.pdf

Prehardened to around HRC30. It cuts beautifully. With carbide with 0.020" depth of cut, the surface is like a mirror.

 

[PeterT]

Swedish tool steel. My god man. I live here. All we have is cows, CO2 & 90% of our steel is round & hollow LOL.
Joking aside, it would be interesting to try that. I have had very little experience with 4140 but I've seen some nice fixtures & tooling made from (maybe specific HT) grades. I might stand a better chance of acquiring that.

 

[thestelster]

Swedish tool steel. My god man. I live here. All we have is cows, CO2 & 90% of our steel is round & hollow LOL.
Joking aside, it would be interesting to try that. I have had very little experience with 4140 but I've seen some nice fixtures & tooling made from (maybe specific HT) grades. I might stand a better chance of acquiring that.

Haha!!

[email protected] 2595 Meadowvale Blvd. Mississauga, ON L5N 7Y3

 

[Tom Kitta]

Here is exact process. Took 2h not including squaring the part.
You can see each step.
Depth is 0.375. Wide is 1.3 this is for square hole.
For dovetail cut. 0.17 per side. Distance between 1/4 em pins is. 0.990.

This fits Armstrong with tiny wobble, maybe few thou. Way better then shars.

This will be for 1in boring bar.

Hope you guys find this of use. Just did it today, on my birthday.

 

[YYCHM]

Hope you guys find this of use. Just did it today, on my birthday.

Happy birthday Tom.

Ya, I could get a 60 deg endmill and it would go a hell of a lot faster... but but but... I have a shaper that should do the same thing

 

[Tom O]

Happy birthday Tom!

 

[Darren]

And even with 0.0000" DTI runout, your steel blank might be stress relieving once a big asymmetrical notch has been removed from one side.
My China block surfaces look ground, maybe semi hardened? ** meant to add, maybe heat normalized as part of process**

That can happen on cold rolled. I had issues with that on my taper attachment build. Hot rolled not so much.

 

[Janger]

Swedish tool steel. My god man. I live here. All we have is cows, CO2 & 90% of our steel is round & hollow LOL.
Joking aside, it would be interesting to try that. I have had very little experience with 4140 but I've seen some nice fixtures & tooling made from (maybe specific HT) grades. I might stand a better chance of acquiring that.

I busted a gut laughing thanks Peter haha. Moo

 

[Susquatch]

Swedish tool steel. My god man. I live here. All we have is cows, CO2 & 90% of our steel is round & hollow LOL.

This was absolutely HILARIOUS! All we have is cows and CO2.

BUT Only 90% of our steel???

 

[YYCHM]

And finally success.... no shim required

Started out a good 2mm too narrow and worked the dove tail open a smidge at a time on the shaper. Was an all afternoon venture

Question - Are the aluminum holders worth finishing or will they just give me grief down the road?

 

[PeterT]

Maybe for light duty but why bother unless its just prototyping for the real ones. Guessing 6061 aluminum but anyways certainly won't be as strong as steel for this application. Not just the dovetail but the toolholder slot set screws.

Re the set screws, my early China ones were actually IMP but seems like they are all now metric, M8? You can get dog point style on Ebay/Ali pretty reasonably but I've used regular set screws too.