# Making some screw less vise hold downs



## WobblyHand (Jan 19, 2021)

So, finally got around to completing a drawing for me to machine some hold downs for my new screw less vise that I just received.  For some reason I couldn't visualize what I wanted to do.  So I have a dxf drawing.  Or pdf.  The inspiration for the hold down can be found on the Little Machine Shop website.  They call it a Z hold down. 

I'd like to make 6 of them.  My plan is to start with a piece of 1.5 x 0.75 low carbon stock, cut it to 5.25" and mill out the basic profile except for the little 0.06 x 0.06 feature. That's just to make it easier to hold in the vise.  Then drill the holes.  I have no idea how I can get the 45 degree cut at the moment, but it's only for aesthetics.  If I had more 'stuff' that would be easier.  No matter.  I'll have to make some sort of spacer, just so the piece can be clamped in the vise.  At the end, I was hoping to cut off the finished pieces one by one with a slitting saw.  Is this an ok plan?  Any things to watch out for?  

Your guidance sought.  This is the part where beginners mess up, the order of operations.  They (me) also often don't realize when there's a vastly easier way to do things.


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## Mitch Alsup (Jan 19, 2021)

I see little advantage to the z-profile over a profile where the side the screw goes through is level with the part that is pushing down on the vise.
That is only cut out the part that grabs the vise and leave the rest square--unless you are fighting some kind of clearance issue.


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## WobblyHand (Jan 19, 2021)

Thanks for your observation.  Not knowing any better, I attempted to roughly duplicate the profile.  At least with the vise I have, the flat will not be level, actually it will slightly tilt upwards towards the vise.  Does this matter?  Haven't cut any thing yet, so all's fair.


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## Mini Cooper S (Jan 19, 2021)

I agree with Mitch and would advise to also add a radius inside the hook that clamps the vise for strength.  That sharp corner is a stress riser for cracking.
Also, make the clamp longer, the short distance from the end to the hole will cause all the clamping pressure to it clamp the table with the vise acting as a step block.

Richard


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## WobblyHand (Jan 19, 2021)

Mini Cooper S said:


> I agree with Mitch and would advise to also add a radius inside the hook that clamps the vise for strength.  That sharp corner is a stress riser for cracking.
> 
> Richard


I think I have an end mill that's got a slight radius to it at the tips.  Hope I have something close.  I don't have that big of a collection.


Mitch Alsup said:


> I see little advantage to the z-profile over a profile where the side the screw goes through is level with the part that is pushing down on the vise.
> That is only cut out the part that grabs the vise and leave the rest square--unless you are fighting some kind of clearance issue.


Took me a couple of readings to have this sink in.  I can skip the nubbin.  Less machining.


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## WobblyHand (Jan 19, 2021)

Is something like a 0.020" radius ok?


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## Mini Cooper S (Jan 19, 2021)

WobblyHand said:


> Is something like a 0.020" radius ok?


Better than nothing but I would probably go about 1/16".  The bigger the better because it is adding strength to the part and distributing the stress to a larger area.  Did you catch the editing that I did to my other post?
Richard


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## Mitch Alsup (Jan 19, 2021)

WobblyHand said:


> Took me a couple of readings to have this sink in.  I can skip the nubbin.  Less machining.



'Zactly !


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## higgite (Jan 19, 2021)

WobblyHand said:


> Thanks for your observation.  Not knowing any better, I attempted to roughly duplicate the profile.  At least with the vise I have, the flat will not be level, actually it will slightly tilt upwards towards the vise.  Does this matter?  Haven't cut any thing yet, so all's fair.





WobblyHand said:


> Took me a couple of readings to have this sink in.  I can skip the nubbin.  Less machining.


Wobbly, I don’t think you want the clamps to be tilting upward. When you tighten them, they will tend to push the vise sideways out of tram. Conventional wisdom is to have a clamp tilting slightly downward at the contact point so that it clamps without pushing or pulling. That is actually the purpose of the “nubbin” on the underside of the clamp body. Otherwise, I like your plan.

Tom


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## WobblyHand (Jan 19, 2021)

@higgite yes, for clamping I _do_ want the flat tilting downwards.  That's the way I use regular hold downs on the mill.  Well, time for version 2!  At least this time, I won't have forgotten how to use the CAD program.  It doesn't take very long before CRS sets in.  That's not cold rolled steel, by the way.  I'll make the pieces taller.  C'est la vie.


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## WobblyHand (Jan 19, 2021)

Mini Cooper S said:


> Better than nothing but I would probably go about 1/16".  The bigger the better because it is adding strength to the part and distributing the stress to a larger area.  Did you catch the editing that I did to my other post?
> Richard





Mini Cooper S said:


> Also, make the clamp longer, the short distance from the end to the hole will cause all the clamping pressure to it clamp the table with the vise acting as a step block.


I have a real mill hold down in front of me.  It's about 2.5" long, 1" wide and 0.5" thick (one of my smallest ones).  I need to have the far end of the hold down on a pedestal, or one of those stepped triangle spacers.  Was hoping for something more compact than that.  If that's not possible, might as well get a couple more shorties (2.5") and use them instead.  Can always use more general purpose hold downs.  Only place I have been able to find these short ones for 3/8 studs is at McMaster.  They are $9.35 each.  Of course I could always use longer ones as well.  

So you solved my problem.  I'm still going to see if I can come up with something more compact and single piece.  Not sure that I can with the stock I have.  A wag on this I need 1" x 1" stock.  Mill an "L" with radius corners, drill holes, maybe radius the part that contacts the table.  Much easier design.  Ordered the 1x1 off eBay.  

In the mean time, I'll just use the vise...


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## Jim F (Jan 19, 2021)

The LMS clamps are $6.73 ea.


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## WobblyHand (Jan 19, 2021)

Jim F said:


> The LMS clamps are $6.73 ea.


Of course they are.  Plus shipping.  Not actually the point for me.

The point is for me to get used to thinking mechanically (and creatively) to design something.  There's lots of items out there to buy, not all of which are designed or made well.  Sometimes you can buy your way out of a problem.  Other times, you really do have to make something custom.  I'm practicing for that time when that special something isn't purchasable.  Some might say it's wasting my time, others might say I'm just sharpening my saw.  

The stock can be used for all kinds of stuff.  This thread made me realize that there's no need to make these clamps at all, since I already own good enough hold down clamps.  Or I could make some compact hold downs, if I come up with an adequate design.  The suggestions received in this thread were very helpful.  The actual metal cost for the part might be $2.50.  Of course, a few bits of tooling need to be sourced, because my shop is sparsely equipped, but I get to reuse the tooling for making other stuff.  

If I buy the clamps, I only have clamps.  If I make the clamps, I get some additional useful tooling, and learn how to be a better machinist.  For me, the latter choice (make) is better for me.  It fits my goals.  Your choice may be different.


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## higgite (Jan 20, 2021)

WobblyHand said:


> @higgite  It doesn't take very long before CRS sets in.  That's not cold rolled steel, by the way.


Join the club. I too have CRS. Problem is I can't remember where I left it. 

Tom


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## higgite (Jan 20, 2021)

WobblyHand said:


> Of course they are.  Plus shipping.  Not actually the point for me.
> 
> The point is for me to get used to thinking mechanically (and creatively) to design something.  ...........
> ...........
> If I buy the clamps, I only have clamps.  If I make the clamps, I get some additional useful tooling, and learn how to be a better machinist.  For me, the latter choice (make) is better for me.  It fits my goals.  Your choice may be different.


Wobbly, I like the way you think, hobby machinist that I am. Why buy something for $7 when you can make it for $20, right?  

I used clamps from a standard clamp set to hold my screwless vise for a long time and then decided I wanted something more compact. Like you, I got my inspiration from the LMS clamp drawing. This is what I wound up making to fit my vise. The dimension not shown is width of 1". Material is 1018. I used a corner rounding end mill to form the pivot. I didn't want a sharp corner bearing down on the table. Could have done the same with a file, but hey, a man has to have more tools, right?

Tom


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## WobblyHand (Jan 20, 2021)

Well, duh, now I know that one can't use an ordinary hold down for the vise AND use 6" parallels.  The hold down nuts are higher than the bottom of the vise.  


Looked into using a SHCS instead, but the head is still too high.  Sure I could machine the head thinner, or even buy a low profile head SHCS, but the hold downs are relatively tall and wide.  They also interfere with my saw arbor (due to the arbors ridiculous length below the blade).  Back to the drawing board...  Think I can make the top surface of the hold down lower by nearly a 1/4" and counter-bore a screw through it.


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## WobblyHand (Jan 20, 2021)

higgite said:


> Wobbly, I like the way you think, hobby machinist that I am. Why buy something for $7 when you can make it for $20, right?
> 
> I used clamps from a standard clamp set to hold my screwless vise for a long time and then decided I wanted something more compact. Like you, I got my inspiration from the LMS clamp drawing. This is what I wound up making to fit my vise. The dimension not shown is width of 1". Material is 1018.
> 
> ...


That's pretty close to what I was sketching!  I thought I would counter-bore the screw for lower profile. 

I'm a little confused about the sketch.  What is the height from the table to the bottom of the slot?  Mine is 0.475"  To make something similar to your idea, I would have to increase the height of the 0.294" = X section to match my vise?  Otherwise the surface won't tilt down towards the vise?


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## homebrewed (Jan 20, 2021)

My screwless vise has a groove on each side of the base, instead of a series of holes like the one shown on the LMS web page.  So I basically replicated the LMS design but instead of the rod that side of the hold down has a machined-in-lip to fit in the slot.  I don't recall if I changed the height of the step on the other side.  Edit:  very much like the one Tom showed in message #15 above.

One disadvantage of the LMS design is that the counterbored screws can accumulate swarf that's somewhat difficult to remove.  If I ever have a need to replace them, I'd simplify the design by eliminating the counter bore and go with hex head bolts and washers.

The hold downs were the first real project on my mill.


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## Jim F (Jan 20, 2021)

homebrewed said:


> My screwless vise has a groove on each side of the base, instead of a series of holes like the one shown on the LMS web page.  So I basically replicated the LMS design but instead of the rod that side of the hold down has a machined-in-lip to fit in the slot.  I don't recall if I changed the height of the step on the other side.
> 
> One disadvantage of the LMS design is that the counterbored screws can accumulate swarf that's somewhat difficult to remove.  If I ever have a need to replace them, I'd simplify the design by eliminating the counter bore and go with hex head bolts and washers.
> 
> The hold downs were the first real project on my mill.


Our vises have a groove, also.


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## higgite (Jan 20, 2021)

WobblyHand said:


> That's pretty close to what I was sketching!  I thought I would counter-bore the screw for lower profile.


You can barely see on my sketch where I erased a counterbore for a SHCS. I decided against it for the same reason that homebrewed pointed out, a swarf trap, and I didn’t need the clearance.



WobblyHand said:


> That's pretty close to what I was sketching!  I thought I would counter-bore the screw for lower profile.
> 
> I'm a little confused about the sketch.  What is the height from the table to the bottom of the slot?


The bottom of the slot on my vise is 10mm from the bottom of the vise. Does your vise not have slots on each side or are they just that elevated? Another factor may be vise size. Mine is a 90mm Tormach vise.

Tom


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## WobblyHand (Jan 20, 2021)

Good point on the swarf trap.  Well that makes it even easier, I guess.   And maybe stronger.  Oh well, don't get to use my counter-bore tool. Haven't used it since I bought the set!  I bought them since I was doing a lot of counter-boring for a while.  I didn't have the right size end mills so the counter-bores looked wrong.

From the bottom of the vise to the bottom of the slot is 12 mm, not 10 mm, so I do need to add a little bit.  Think I'll practice on a piece of 6061.  Don't have any 1x1 steel stock at the moment.  I just sliced off a piece from some 1" thick 6061 stock.  Faced off the sides.  I'll rough machine it to make a prototype.  See if there's any gotchas that I hadn't envisioned.  Came up to grab my mic that I left at my computer desk.


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## WobblyHand (Jan 20, 2021)

Save for putting a radius on the nubbin, the prototype is good.  Don't have any radius end mills.  Might make the section that goes in the slot be 0.050 thicker.  Even if it's 0.375" thick, it's sloping towards the vise which is good.  Found that a 1.25" bolt with a washer works, just barely making 3 threads.  Now the long wait (a week I hope) for tooling and some steel.  In the mean time, have to scrounge up some hex head bolts, I know I have some squirreled away...


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## WobblyHand (Feb 5, 2021)

Version 2, in A36 steel done!  Made the piece that inserts in the slot a little thicker to make it stronger.  Only bad thing about working with steel is getting lots of splinters.  The radiused carbide mill had no problem with the A36 and left a pretty good finish.  Still need to get some regular hex head bolts. My stash only had 3 long hex heads, which I didn't want to cut down.  Have to order some 1.25" bolts.

I went through this effort because I've been getting jaw lift on my regular vise.  It was hard to square the pieces.  Over 2.5 thousands of lift.  On this screwless vise, I get 0 lift at the fixed jaw and maybe 0.0004" at the movable jaw if I really crank it down.  Stefan Gotteswinter was right, the vises are made out of rubber.  It was really interesting to measure the lift.



Have to say I am pleased how they came out.  The machining gods were not quite as happy and rewarded me with a nice gash in my thumb when I was deburring the pieces.  Must of been those earlier cuss words during the day...


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## higgite (Feb 5, 2021)

Good job, Wobbly! Sorry about your thumb. Burrs are surprisingly lethal.

Tom


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## WobblyHand (Feb 5, 2021)

Thanks.  The steel splinter in my fingertip hurts worse.  Went in deep and probably broke off.  Can't see it with an 8X magnifier.  I know it's there...

For my thumb, it wasn't the burr that got me, but the deburring tool slipped off the edge off the part and into the skin just below my cuticle.  I was surprised how much it bled.  Washed the thumb, slathered with antibiotic and bandaged it.  Thumb doesn't hurt at all.


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## fitterman1 (Oct 18, 2022)

Old thread, but whats wrong with deburring with a file, been doing it for 30 yrs. Only ever use a noga type on round holes.


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## WobblyHand (Oct 19, 2022)

fitterman1 said:


> Old thread, but whats wrong with deburring with a file, been doing it for 30 yrs. Only ever use a noga type on round holes.


Nothing is wrong with using a file.  I just happened to pick up what was nearby.  Files work fine, deburring tools are handy for somethings.  Love the Noga deburring tools for round holes.  

Was interesting to re-read this old thread.  I've learned a bit in the past year and a half.  As usual, everyone on HM has been a great help.


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## higgite (Oct 19, 2022)

fitterman1 said:


> Old thread, but whats wrong with deburring with a file, been doing it for 30 yrs. Only ever use a noga type on round holes.


Nothing wrong with a file, nobody said there was, but whoever dies with the most tools wins.


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## Parlo (Oct 19, 2022)

I would consider making the heel of the clamp slightly smaller than the width of the tee slot. Then make this end go all the way to the bottom of the tee slot so you don't bruise the bed.
Please see the video at:
0.11 Top left shows one clamp on it's side
0.41 + 0.49 Show the clamp in the tee slot with the heel going to the base of the tee slot.


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## WobblyHand (Oct 19, 2022)

Parlo said:


> I would consider making the heel of the clamp slightly smaller than the width of the tee slot. Then make this end go all the way to the bottom of the tee slot so you don't bruise the bed.
> Please see the video at:
> 0.11 Top left shows one clamp on it's side
> 0.41 + 0.49 Show the clamp in the tee slot with the heel going to the base of the tee slot.


Good idea.  Found that out the hard way.  Now just using scraps of aluminum or steel as a shim under the rounded part, works fine.


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## fitterman1 (Oct 19, 2022)

Parlo said:


> I would consider making the heel of the clamp slightly smaller than the width of the tee slot. Then make this end go all the way to the bottom of the tee slot so you don't bruise the bed.
> Please see the video at:
> 0.11 Top left shows one clamp on it's side
> 0.41 + 0.49 Show the clamp in the tee slot with the heel going to the base of the tee slot.


Some good ideas in that video.
As Wobblyhand mentions, bruising of the table face by the heel of a clamp is something we all have to be wary of. The rounding of these heels to allow self adjustment is also a good idea but allows the clamping forces to be concentrated on a thin line. As he has learnt, there should be packing under this heel to prevent damage to the table bed datum surface, so we don't end up inadvertently causing damage and creating errors in future setups.
The is a formula that goes F= M x A, which states that force is equal to mass x area. In this statement you should be able to see that the higher the force applied on a given area, the more mass we are trying to push through it. Thats why packing, shims, a washer, scrap or anything is needed to prevent damage. Everything is "plastic" to some degree no matter how hard you think it is.


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## Parlo (Oct 20, 2022)

The idea is predominately aimed at bespoke clamps for a single purpose, in this case a vice. I think it is well worth spending the extra time to incorporate the deep heel for future simplicity and repeatability. I would not want to look for packing pieces each time I mount the vice. If the heel is a few though higher than the clamping face to the tee slot base distance, the clamp will distort to have a flat contact with the base of the heel on the tee slot base. This will not mark the tee slot base and also aligns the clamp square to the vice edge. I use a captive spring between the tee nut and the clamp for even simpler installation.


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