Mod Vise on a Shapeoko creates Aluminum Projectile

Has anyone tried using a Saunders Mod Vise on a Shapeoko? I know they have one setup up on a shapeoko in their shop but, this thing scares me. I’ve now had 4 failed attempts at keeping 1x2x4 6061 bar stock in the mod vise and running an adaptive tool path on it. I reached out to them and I know I’m using it correctly. I’ve faced all sides of the stock to make sure any small radius on the bar aren’t preventing clamping forces. Each attempt I’ve felt like I’ve gotten a good clamp, but when the adaptive path on a single flute 1/4" tool runs around the outside of the stock it rips it out and shoots it out of the clamp. I thought for a while that it was something goofy in my cam, but I decided to rerun a previous cam that works fine with double sided tape. I can’t figure out if I’m just expecting to much from the vise or if certain tool paths just can’t be used with this type of vise. Anyone out there tried these on a shapeoko?

Saunders Machine Works

Are you just linking to their shop or did I miss something?

I use a design like the Mod Vise often on my Nomad, biggest source of workholding failure is how rigidly the vise is attached to the table. Often my Mitee-Bite clamps will start to move the slotted vise across the table; it’s hard to get enough friction between the vise and the table. Definitely make sure the table is clean with no cutting oil on it before you use it.

How are you fixturing the vise to your table?


It’s bolted down tight using 1/4 -20 bolts. I’m not seeing any shift in the vise but instead the bite force isn’t great enough to hold the bar in place. I’ve adjusted and readjusted it , hoping to get it tight enough that the teeth would really Mark the surface of the bar but I can’t seem to get that amount of holding contact. A good yank underneath the bar in the vise will get it out

Something sounds weird about it then, I can pick up my Nomad by the stock held in my homemade mod vise.

Could you take a photo of your setup and share it with us?


I provided a link to the manufacturer that you were asking questions about. You got a response from one knowledgeable person, and 20+ users were wondering what piece of equipment you were asking questions about.


Yeah that’s how I feel about it also. I must be missing something but just not sure why I can’t get a super strong bite. The thing is it can only work one way, stock goes next to the talons, you set the hard vise bolt downs , then tighten down the large eccentric vise screws to apply biting tension… but for some reason that’s not giving me the same bite , if feels tight but in reality it’s not. I’ll try and take a picture

Ok well I never saw the 20+ people asking about what a mod vise was

For reference this is how it’s setup. A good finger pull underneath either the left end or right will get it out of the vise even though it feels solid in there it’s not

Replace the MDF with a metal threaded table?

Place an aluminum sheet on the MDF which is thick enough to not give and bolt the clamps to that?

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Yeah that’s my next move. I was wondering last night if the subtle flex in the MDF and threaded inserts isn’t rigid enough for this kind of vise…funny thought I recall Saunders having the same setup but hard to say.


Saunders mount the mod vise to an aluminium plate first, then screw that plate to the MDF.
See their latest shop update video on YouTube.


Yeah I’ve been talking to them this morning and they just confirmed the mdf with inserts isn’t rigid enough for the vise. I’m going to add an intermediary plate to help make it more rigid and hopefully that will solve it

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that should solve it (solid sub plate of some sort).

otherwise the only other thing that could hinder is not working within the clamping range of the vise/clamps. parts need to be consistent dimension between vise or you need to adjust the vise each time.

For sure. They mentioned they were going to have a Shapeoko bed coming from them pre threaded so I might hold out and


Even with a threaded bed, a sub plate is desirable and imo a must have.


If the left part of the vise had the screw in alignment of the talon grip it should be more rigid.

Not sure I’m following why they would be

The leverage effect will work with you and not against you. Not sure how to explain.

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