# Floating vise build



## David_R8 (Apr 23, 2021)

In this thread I revealed my dislike of my drill press vise. I did a bunch of searching for batter options and came up somewhat empty. @trlvn posted a link to a vise build by Mr. Pete that caught my attention.
I watched the build series and decided to build one.
I have stock on it's way and the 1/2-10 Acme tandem tap arrived this week.







If you've never tapped an Acme thread it is not for the faint of heart. 
The tap drill is 13/32" or .406". My tap has a minor diameter of you guessed it, .406. Needless to say the tap has to remove a lot of material.
My first attempt at tapping I couldn't get the tap to start no matter how hard I tried.

Tonight I made another attempt starting with a 29/64" (.453) I started the tap in the mill but had to move it to the vise and finish by hand.
Using my 12" Patience and Nicholson tap wrench I went at it. Definitely really tough going for the first part of the tap. I could see the tap twisting and I feared it might snap. Lots of Tap Magic and I made it through!






My plan is to start with a a 7/16-10 Acme tap on a 13/32 hole. This should clear away enough material to give me a good chance of tapping the hole and achieving the full thread depth.


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## YYCHM (Apr 23, 2021)

What material are you making the nut out of ??


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## David_R8 (Apr 23, 2021)

There isn't a nut, the moving jaw of the vise jaws is tapped for the 1/2-10 Acme thread. It slides along the rod on the left side.


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## YYCHM (Apr 23, 2021)

Jeepers…. twisting a 1/2" tap  Is adapting it for a brass nut an option?  That would make it replaceable as well.


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## kevin.decelles (Apr 23, 2021)

I hear ya on the pucker factor for tapping acme. The 1”-5 brass nut I did took an incredible amount of force, but it too worked out

Great work!


Sent from my iPhone using Tapatalk


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## Darren (Apr 23, 2021)

Or a cast iron sleeve nut glued in. Cast taps like butter


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## David_R8 (Apr 23, 2021)

I actually thought about buying a 1/2-10 Acme coupler nut from McMaster, turning it round, boring the jaw and pressing it in.
If I break the tap that's what I'll do.
https://www.mcmaster.com/93023A673/

@dfloen what's is a sleeve nut?


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## YYCHM (Apr 23, 2021)

I tapped three 1/2-10 LH ACME brass nuts no problem at all.  Twisting a 1/2" tap seems rather excessive.


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## David_R8 (Apr 23, 2021)

YYCHM said:


> I tapped three 1/2-10 LH ACME brass nuts no problem at all.  Twisting a 1/2" tap seems rather excessive.


This is mild steel though.


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## YYCHM (Apr 23, 2021)

David_R8 said:


> This is mild steel though.



I hear you... What I want to know is how you got it started on you mill?  All's I've accomplished so far trying to tap on my mill was to drill/mill an oversized hole


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## David_R8 (Apr 23, 2021)

YYCHM said:


> I hear you... What I want to know is how you got it started on you mill?  All's I've accomplished trying to tap on my mill was to drill an oversized hole


I just chucked the tap in the Jacobs chuck, dialed the VFD frequency down to 22 hz and let it go. Got about two'ish turns in before if stopped.


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## Darren (Apr 24, 2021)

David_R8 said:


> I actually thought about buying a 1/2-10 Acme coupler nut from McMaster, turning it round, boring the jaw and pressing it in.
> If I break the tap that's what I'll do.
> https://www.mcmaster.com/93023A673/
> 
> @dfloen what's is a sleeve nut?



an internally threaded , nut that is round on the outside. Pretty easy if you find a small slug of cast iron. It really threads and machines nice.


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## Darren (Apr 24, 2021)

When i am power tapping in the mill (hand tapping is for suckers  ), I chuck the tap in the drill chuck snug, but not super tight, I'd rather a tap slip than break, and then run it in at like 100ish rpm, when it slips, back it out, tighten it up to get a feel, then run it in again, repeat as neccesary. lotsa oil. But acme taps need torque. I have er32 tap collets. They dont slip. They punch through or break taps. Find a happy medium. I'd run some test pieces first.  If the tap drill is 406 and the root is 406, Godspeed. Can you single point it?


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## Chipper5783 (Apr 24, 2021)

For power tapping, go with a spiral tap- spiral point for chips forward, spiral flute for chips back, the cut with much less torque as there is more of a shearing action.  Of course the chips don't pack in either.  When hand tapping with one of the spiral taps it is amazing how much easier it goes.

I doubt spirals are an option for an Acme thread.  Per the statement above , single point in the lathe (even just to rough it in, finish with the tap).  Of course you could single point thread mill the Acme - sounds like all the justification needed for getting a CNC mill.


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## David_R8 (Apr 24, 2021)

Unfortunately single pointing is not an option as my internal threading tool is 1/2” diameter so it’s too large to fit. 

My plan is to start with a a 7/16-10 Acme tap on a 13/32 hole. This should clear away enough material to give me a good chance of tapping the hole and achieving the full thread depth.


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## PeterT (Apr 24, 2021)

I've heard those taps can be tough sledding. Is it a photo parallax optical illusion - it almost seems like there are 2 stages of graduated taper? I dont know much about these but assumed it would be a single taper & then straight final thread size.


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## David_R8 (Apr 24, 2021)

PeterT said:


> I've heard those taps can be tough sledding. Is it a photo parallax optical illusion - it almost seems like there are 2 stages of graduated taper? I dont know much about these but assumed it would be a single taper & then straight final thread size.



Your eyes are not playing tricks on you. 
It’s a tandem tap. The first half roughs in the thread form, the second half finishes it. 
I’ve read that acme taps come as roughers and finishers but I’ve never seen them for sale.


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## CalgaryPT (Apr 24, 2021)

David_R8 said:


> ... I could see the tap twisting and I feared it might snap.


I know that exact feeling when you see the tap twist. Absolute terror.


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## David_R8 (May 3, 2021)

Picked up the Acme rod this afternoon. 
The test pieces that I drilled and tapped are an excellent fit. 
This bodes well for my plan to drill to size, tap with a 7/16-10 Acme tap and follow with the 1/2-10 tap.


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## David_R8 (May 7, 2021)

My 7/16-10 Acme tap arrived today. 
Nothing left to do but the doing!


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## DPittman (May 7, 2021)

David_R8 said:


> My 7/16-10 Acme tap arrived today.
> Nothing left to do but the doing!


I bet that will take some grunt to turn


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## David_R8 (May 7, 2021)

DPittman said:


> I bet that will take some grunt to turn


Yup...my plan is to drill to size for 1/2-10 Acme but pre-tap with the 7/16-10 first to take out the bulk of the material. Then follow up with my 1/2-10 Acme tandem tap.


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## DPittman (May 7, 2021)

David_R8 said:


> Yup...my plan is to drill to size for 1/2-10 Acme but pre-tap with the 7/16-10 first to take out the bulk of the material. Then follow up with my 1/2-10 Acme tandem tap.


That's thinking! I would not have thought of that.


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## PeterT (May 7, 2021)

Something in the back of my mind seems to remember hearing that pre-tapping is not recommended even though the same pitch & thread form. But I can't think of why. Maybe because the smaller tap is not being guided within its normal matching smaller bore, so there is a possibility to drift off axis inside the larger 0.500 bore & cut into one side more than the other & thus influence the bigger tap coming in after? I could be off base, like I say, foggy recollection.


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## Alexander (May 8, 2021)

Internal acme threads are so hard to cut at home. I bought an inserted threading bar for a simple lathe cross slide nut. If the tap works then great. I usually see these acme taps used in rebuilding shops to chase threads.


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## David_R8 (May 8, 2021)

PeterT said:


> Something in the back of my mind seems to remember hearing that pre-tapping is not recommended even though the same pitch & thread form. But I can't think of why. Maybe because the smaller tap is not being guided within its normal matching smaller bore, so there is a possibility to drift off axis inside the larger 0.500 bore & cut into one side more than the other & thus influence the bigger tap coming in after? I could be off base, like I say, foggy recollection.


Yes I thought this might be an issue. 
I'll drill and run the 7/16-10 on my mill so that I maintain location of the hole.


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## David_R8 (May 8, 2021)

Alexander said:


> Internal acme threads are so hard to cut at home. I bought an inserted threading bar for a simple lathe cross slide nut. If the tap works then great. I usually see these acme taps used in rebuilding shops to chase threads.


Indeed. It took an oversize hole to even start the tap on two tests that I did, Even then the force required is astounding.


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## YYCHM (May 23, 2021)

Where is this project at?


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## David_R8 (May 23, 2021)

It’s sitting on my bench waiting for me the finish putting the forks from my Honda NT650 back together.


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## Tom O (May 23, 2021)

Why the 2 difference Springs?


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## David_R8 (May 23, 2021)

Tom O said:


> Why the 2 difference Springs?


They are the same, I had just pullled them out of the fork legs, one was just installed upside down. It's a former racebike so it had a bunch of suspension work done to it. Not all of it correctly.


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## YYCHM (May 23, 2021)

David_R8 said:


> They are the same, I had just pullled them out of the fork legs, one was just installed upside down. It's a former racebike so it had a bunch of suspension work done to it. Not all of it correctly.



So that should have been a matched pair?


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## David_R8 (May 23, 2021)

YYCHM said:


> So that should have been a matched pair?


They are matched pair, one was just installed upside down. They have progressively wound coils, the other end of the one on the right looks exactly like the one on the left.


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## Tom O (May 24, 2021)

Ok I had to ask.


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## David_R8 (May 24, 2021)

I was equally perplexed when I pulled them out.


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## YYCHM (Sep 15, 2021)

Where is this project at?


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## David_R8 (Sep 15, 2021)

Sitting quietly on my bench.


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## David_R8 (Sep 15, 2021)

I've been swamped with work and house projects.


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