▼
Posts: 16,598
Threads: 2
Joined: Oct 1999
07-08-2024, 05:22 PM
(This post was last modified: 07-08-2024, 05:24 PM by Tapper.)
I'm rebuilding my woodworking workbench, and in the process replacing the old face vise with a Record 52 1/2 model (9" wide cast iron face.) The old vise failed. In the photo below, I've mortised the faceplate into the wooden face block about 3/16" deep. These Record vises have a canted angle to the face, built in. It equates to about a 1/8" gap at the bottom of the wooden faceplate with the vise just resting on the wooden faceplate (maybe 1 1/2 to 2 degrees.)
When bolted to the wooden faceplate, the faceplate assembly will not fit flat against the edge of the workbench top due to the angle. I've read discussions online about this issue and it seems the theory is that the top of the clamp will be tighter and prevent the work piece from moving. I've always liked vise faces to be perfectly (as much as possible) parallel with each other.
I can probably taper the mortise and get it close to parallel. What are your thoughts?
Thanks,
Doug
[attachment=51743]
▼
Posts: 5,182
Threads: 0
Joined: Jan 2014
Location: Santa Maria, Ca
Your plan to taper the mortise to make up for the slant sounds reasonable.
I am not sure the "top of the clamp will be tighter and prevent the work piece from moving" part
is reasonable at all. More surface area in contact with the workpiece would always be better.
I'm with you, I like vise jaws to be as parallel as possible.
Mark Singleton
Bene vivendo est optimum vindictae
The Laws of Physics do not care about your Politics - Me
Posts: 1,730
Threads: 13
Joined: Jul 2001
I think the "toe-in" of the movoing jaw is designed that way on purpose :-)
I did some quick tests with my 11" Jorgenson - which also has about 1/8" of toe-in:
If a workpiece is clamped with (only) the top of the moving jaw, the bottom of the moving jaw actually moves past parallel. This makes sense - there's a bending moment from the screw to the top of the moving jaw.
If a workpiece is clamped only at the bottom of the moving jaw, the top of moving jaw become parallel.
If a workpiece is clamped across the entire face of the moving jaw (like if you were holding a board for edge-planing) the top and bottom of the moving jaw are parallel.
My conclusion is the resting "toe-in" is designed by the manufacturer to result in parallel clamping under most scenarios.
It raises the concern (TBC) that if you create a moving jaw with a face that's parallel 'at rest' you may reduce the clamping surface under load.
-Mark
If I had a signature, this wouldn't be it.
▼
Posts: 16,598
Threads: 2
Joined: Oct 1999
(07-09-2024, 08:12 AM)MKepke Wrote: I think the "toe-in" of the movoing jaw is designed that way on purpose :-)
I did some quick tests with my 11" Jorgenson - which also has about 1/8" of toe-in:
If a workpiece is clamped with (only) the top of the moving jaw, the bottom of the moving jaw actually moves past parallel. This makes sense - there's a bending moment from the screw to the top of the moving jaw.
If a workpiece is clamped only at the bottom of the moving jaw, the top of moving jaw become parallel.
If a workpiece is clamped across the entire face of the moving jaw (like if you were holding a board for edge-planing) the top and bottom of the moving jaw are parallel.
My conclusion is the resting "toe-in" is designed by the manufacturer to result in parallel clamping under most scenarios.
It raises the concern (TBC) that if you create a moving jaw with a face that's parallel 'at rest' you may reduce the clamping surface under load.
-Mark
Hi Mark,
IIRC you're an engineer and bring up an important point. I'm not a degreed engineer but worked in the field and around a lot of them in aerospace. I did think about the moment arm perspective but was worried that since this vise is made out of cast iron, there would not be much elasticity for the "spring effect."
Maybe I've been overthinking this one. And yes, most definitely the angle is built into the design of the vise.
Doug
Posts: 12,604
Threads: 0
Joined: Aug 2003
Location: Wapakoneta, OH
I agree with Mark, and I have a Record 52 1/2 as well as the Jorgenson vises. They both work well as designed.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
Posts: 16,598
Threads: 2
Joined: Oct 1999
07-09-2024, 11:21 PM
(This post was last modified: 07-09-2024, 11:27 PM by Tapper.)
Here is a pic of the vise with jaw in place. The vise face has been lag bolted to the wooden jaw. You can see the gap at the bottom, approximately 1/8". The rest of the vise hardware is not installed yet. The two rods have just been inserted through the holes in the baseplate.
Therefore, I can't test it under pressure yet to see if clamping something tight will make it come to parallel. I've never owned one of these vises before so I'm not familiar with this angled face feature. Are those of you that have, saying that when you clamp something tightly there is enough elasticity to apply pressure on the entire face of the board being clamped?
Thanks,
Doug
[attachment=51760]
Posts: 12,604
Threads: 0
Joined: Aug 2003
Location: Wapakoneta, OH
07-10-2024, 07:57 AM
(This post was last modified: 07-10-2024, 08:09 AM by fredhargis.)
My Record isn't mounted on a bench at the moment or I would do this with it (sitting in the basement waiting for my long planned, but not yet built second bench), but here's pics of my Jorgy 41012. The first pic is with the faces just butted together. the gap at the bopttom on this one is.09", measured with feeler gauges. The second one is with the screw tightened...no gap. What I fear might happen with your initial plan is that if the faces meet evenly while loose, the top might be open (or not gripping the workpiece securely) when tightened down. My jaws are 4 1/4" tall, I think yours might be a little taller...which would open up that gap (I think).
[attachment=51761]
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
Posts: 16,598
Threads: 2
Joined: Oct 1999
Thanks for those pics and your comments, Fred. Whenever I get the rest of the hardware on the vise and get it operational I'll give it a test run to see if the gap closes, as on your Jorgy.
Doug
Posts: 1,730
Threads: 13
Joined: Jul 2001
Tapper - I noticed this interesting comment on Amazon’s “Manufacturer’s description’ for the Record 52 1/2 - see esp the second sentence.
“The toe-in provides maximum grip along the top edge; this feature must be retained when fitting wooden cheeks. ”
https://www.amazon.com/Record-52-1-2ED-R...B0000223R5
Also Paul Sellers has a blog entry on toe-in
https://paulsellers.com/2018/08/vise-toe-in-out/
Lastly and unrelated, I noticed you’ve put a massive wooden cheek on the moving jaw and am curious why you made it so much bigger than the jaws themselves?
-Mark
If I had a signature, this wouldn't be it.
▼
Posts: 16,598
Threads: 2
Joined: Oct 1999
07-10-2024, 09:18 PM
(This post was last modified: 07-10-2024, 10:39 PM by Tapper.)
(07-10-2024, 10:54 AM)MKepke Wrote: Tapper - I noticed this interesting comment on Amazon’s “Manufacturer’s description’ for the Record 52 1/2 - see esp the second sentence.
“The toe-in provides maximum grip along the top edge; this feature must be retained when fitting wooden cheeks. ”
https://www.amazon.com/Record-52-1-2ED-R...B0000223R5
Also Paul Sellers has a blog entry on toe-in
https://paulsellers.com/2018/08/vise-toe-in-out/
Lastly and unrelated, I noticed you’ve put a massive wooden cheek on the moving jaw and am curious why you made it so much bigger than the jaws themselves?
-Mark
Kepke -
Thanks for the links; all the explanations seem to be consistent in explaining the toe-in. As I mentioned earlier, this is the first vise of this design I've owned. When I get it all together and under pressure I'll be a happy camper if when I clamp a 4 1/2 or 5 inch wide board in it, that it winds up parallel to the stationary side, i.e. applying pressure equally across the entire face of the workpiece.
I've buried the stationary cast iron plate in a new edge board because I wanted it in the same plane as the edge of the workbench top and wanted to clamp against wood rather than metal. I think it's the same design I saw on Christian Becksvoort's bench in an online tour of his shop, if that means anything.
As to the "massive wooden cheek" I retrofitted the original wooden cheek to fit this Record vise. This workbench was the featured article in Woodsmith issue #50. I built it exactly according to the plan. When the original vise was working (an inexpensive quick-release model per the plan) it worked fine. That vise with this same wooden cheek was parallel to the front edge of the benchtop by design. Having used it for 20+ years with no gripping problems before the cast iron collar that controlled the quick-release feature broke, I did enjoy the large the large clamping surface. BTW, no vise "guru" am I as this is the first and only workbench I've ever built, so I suppose I'm a novice at this.
BTW, is there any downside to having a larger wooden cheek?
Doug
|