Talon Grips for fixturing

[Cedric Eveleigh]

Has anyone here tried using Talon Grips (or something similar) with the Pocket NC vise or with a fixture plate?  https://www.miteebite.com/products/talongrip/

-Cedric

[Mike Henry]

I don't have a PNC yet, but the Talon Grips work great on my  Tormach mill with a couple of different vices.  I wonder if the PNC vise has enough "beef" to make good use of them, though.  Might work better on a fixture plate.

[ashg...@gmail.com]

They would work well on a block mounted to the b table , might steal the idea

[Cedric Eveleigh]

I thought at first that TalonGrips have to be mounted to a vise, but with this example (https://www.miteebite.com/wp-content/uploads/2014/02/talon_grip3.jpg), it seems like that's not necessary. I'm assuming the TalonGrip on the left (in the photo) is the same style as what goes in vises, but I don't know how the TalonGrip on the right works - I'm guessing with some kind of wedging mechanism. It seems like this configuration would be easy to implement with the Pocket NC given that there's no need for a beefy vise or any vise at all.

[gre...@gmail.com]

Yes it's a wedge system, lots of holding force, obviously limited closing range but you can make multiple tooling plates or have different mounting positions on the same plate etc. Also good for batch work.

Cheers,

Graham

[Alex Yates]

Hi Cedric,

I’ve just posted a forum message which links to a workholding system I’ve made for the Pocket NC, which uses OK Vise clamps. You can put knurled jaws on these, which give you a lot of gripping power. It might suit your purposes.

Kind regards,

Alex

[Cedric Eveleigh]

Hi Alex - Thanks for sharing that. However, I'm more interested in Talon grips (and also dovetail vises like the 5th Axis DM12) for the ability to hold stock with very little material in the stock taken up by the workholding. The OK vises seem useful (just like these fixture clamps, which I'm about to try using) but it doesn't seem like they fit the bill for minimizing material taken up by workholding.

-Cedric

[Alex Yates]

Hi Cedric,

You can use the OK Vises to do low profile clamping. It still might not be what you require, but I made a quick video to demonstrate:

https://www.youtube.com/watch?v=331ECDUil-o

In the video, the "knurled attachments" are machined down so that they only hold onto the bottom 2mm of stock. As they bite in, the small serrations on the attachments will still give plenty of grip though.

I'm going to make the "knurled attachments" slightly thicker than they appear in the video. This will allow me to machine more out of them, and gain greater clearance around the part. This video illustrates the idea pretty well though.

Best, Alex

[gre...@gmail.com]

Are the knurled jaws aluminium? They may lose their bite over time.

Cheers,

Graham

[Alex Yates]

Hi Graham,

Yep, they’re Aluminium 7075.  I’ve only used my knurled jaws 4-5 times so far (mainly for holding stock whilst I machine a dovetail into it for my 5th axis DM12), but they’re still biting into the stock absolutely fine. It’s inevitable they’ll dull with time though.

If I were to make them in Steel though, it’d mean that users of the Pocket NC would struggle to machine them down to the size/shape they want/need. The same goes for the ‘soft jaws’. If there was sufficient demand, I’d make some steel ones, but I imagine most would just be happy replacing the Aluminium ones every once in a while, given that they’re relatively inexpensive. Either way, it makes for a pretty flexible workholding system, with A LOT of holding power.

Thanks, 

Alex

[gre...@gmail.com]

I can't really see a time when I would want to machine a knurled jaw. I watched your video about the low profile clamping but I would just use parallels and clamp at the top of the jaws. It gives greater access  to the material which I think is what Cedric wanted. It makes sense for soft jaws to be soft of course and they don't really wear anyway.

Graham

[Alex Yates]

In most cases, you are right, it would be easier to just use parallels (or in this case, use longer grub screws) to raise the stock up. The only thing to bear in mind is that with taller parts, this may raise it outside the Pocket NC’s fairly limited work envelope. So that’s why I’d suggested machining the ‘Knurled attachments’ down, rather than raising the stock up.

That being said, if a few people wanted a Steel ‘knurled attachment’, I’d make it. They’d be more expensive than the Aluminium ‘knurled attachments’  though for obvious reasons.

Best, Alex

[TriManTed]

More ways to hold round stock. What I'm holding has a lip around the bottom and I need to clamp the lip plus the round stock above the lip.

I'm using clamps from ThorLabs.com. They provide a DXF file for every item they have, so you can check the fit by adding it to your design.

This link is for holding pedestals, but it will hold round stock.   https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=887 

Here are table clamps in various sizes, too. https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_ID=191&pn=CL8