Kurt style ball lock vise vs gerardi style vise for 3axis vmc.

[Philabuster]

but cranking to change from big to small to big is driving me nuts, becuase I dont have access to screw tail shaft to do full revolutions, and I have to resort to ratchet, that is a total pain in the ass,

I use a 1/2" drive speed wrench with an impact style universal joint on the end to quickly open and close the 3 jaw chuck on my CNC lathe, then switch to a 24" ratchet to clamp down on the stock. Cranking the jaws with the ratchet alone takes forever. Would you have the room for a speed wrench?

 

[usolutions]

Not really, tried air ratchet, but it also takes lots of time, and is loud AF. also it is not the main and only problem

 

[gregormarwick]

I am currently using Rohm 712 RS vise, prismatic gib full length screw vise, and I hate it. May be I can adjust moving jaw for minimal jaw lift, but cranking to change from big to small to big is driving me nuts, becuase I dont have access to screw tail shaft to do full revolutions, and I have to resort to ratchet, that is a total pain in the ass, as it tends to easily go both ways, instead of engaging ratcheting mechanism. Short throw of wedge jaw, and all top acess to all needed would be more of an upgrade than disadvanage for parts changeover. at least in my case.
View attachment 399523
Also because of this setup I can not allow significant overhang around Y. Or overhanging moving jaw like rohm has

sorry, should have included this image to my original post

Things to be aware of if you go the wedge jaw (Gerardi) route:

• It still takes a little time move the rack jaw, as there are two set screws to loosen, and you will need to clear out chips underneath it before you reposition it. Some, like Rohm, use a pin for this and some, like Komtas, use a tilt lock mechanism which is the quickest to move.
• You need to be very vigilant of keeping chips out from under the jaws or they don't pull down properly. Blow chips out before you release the vice (i.e. while the jaws are already pulled down fully) to mitigate against this, but it still is an extra step that you need to be aware of.
• Table overhang is still a thing with these vices.
• If you really tighten them the base of the vice will deflect upwards in the middle. This is true of any vice, but other vices will deflect the rear jaw long before this happens so it's less apparent. You need to ensure the base of the vice is fixed down in the middle rather than at either end.
• Gerardi are fully rigid, while other makes (Komtas) have a reversible moving jaw carrier that will allow the moving jaw to be either rigid or with lateral rotation. This means that Gerardis and those like them are really not good at clamping parts that aren't perfectly parallel.
• Soft jaws are pretty much not a thing on wedge jaw vices, unless you use an intermediate hard carrier jaw. They do usually have a pretty good range of application jaws.
• It's easy to set up two wedge jaw vices as a split vice for large workpieces, by mounting them end to end and reversing the moving jaw. The fixed jaw is usually removable too if need be.

In summary, wedge jaw vices require more care and cleanliness during part changeover, and are not ideally suited for first ops on raw material. On the other hand, they are far superior in terms of squareness, parallelism, pulldown, and clamping security, so are great for secondary ops where accuracy is paramount.

 

[usolutions]

• You need to be very vigilant of keeping chips out from under the jaws or they don't pull down properly. Blow chips out before you release the vice (i.e. while the jaws are already pulled down fully) to mitigate against this, but it still is an extra step that you need to be aware of.

I think some flexible 3d printed insert into rail should help with keeping it more less clean. Air gun is already permanent part of a loading station.

• Table overhang is still a thing with these vices.

71w rohm at 155 opening is about 650 overall length. In gerardi with 300 opening has 520-540 overall length. So it is a lot less of an issue.

• If you really tighten them the base of the vice will deflect upwards in the middle. This is true of any vice, but other vices will deflect the rear jaw long before this happens so it's less apparent. You need to ensure the base of the vice is fixed down in the middle rather than at either end.

Will keep that in mind, but I think it would be easily fixable.

• Gerardi are fully rigid, while other makes (Komtas) have a reversible moving jaw carrier that will allow the moving jaw to be either rigid or with lateral rotation. This means that Gerardis and those like them are really not good at clamping parts that aren't perfectly parallel.

So far I was mainly using ground/cold rolled stock for most of my operations, so stock parralelism is acceptable level.

• Soft jaws are pretty much not a thing on wedge jaw vices, unless you use an intermediate hard carrier jaw. They do usually have a pretty good range of application jaws.

Catalogue gives multiple jaws, as well as soft jaws, step jaws and hardened gripper jaws(something like mitee-bite). That more.less covers my needs.

• It's easy to set up two wedge jaw vices as a split vice for large workpieces, by mounting them end to end and reversing the moving jaw. The fixed jaw is usually removable too if need be.

Ill keep that in mind

In summary, wedge jaw vices require more care and cleanliness during part changeover, and are not ideally suited for first ops on raw material. On the other hand, they are far superior in terms of squareness, parallelism, pulldown, and clamping security, so are great for secondary ops where accuracy is paramount.

Thank you for your input, very very information dense

 

[Homeshopblob]

Would you have the room for a speed wrench?

Not really,

Often a flex head bent handle ratchet can be the answer. With a minute's practice it's faster than a speed wrench, can be used one handed or two handed, takes less space, and the ratchet you need next is right there in your hand and connected to the socket. Every line auto mechanic I know uses them constantly.

 

[usolutions]

Often a flex head bent handle ratchet can be the answer. With a minute's practice it's faster than a speed wrench, can be used one handed or two handed, takes less space, and the ratchet you need next is right there in your hand and connected to the socket. Every line auto mechanic I know uses them constantly.

also it is not the main and only problem

 

[Homeshopblob]

Have a nice day.

 

[???]

Things to be aware of if you go the wedge jaw (Gerardi) route:

• It still takes a little time move the rack jaw, as there are two set screws to loosen, and you will need to clear out chips underneath it before you reposition it. Some, like Rohm, use a pin for this and some, like Komtas, use a tilt lock mechanism which is the quickest to move.
• You need to be very vigilant of keeping chips out from under the jaws or they don't pull down properly. Blow chips out before you release the vice (i.e. while the jaws are already pulled down fully) to mitigate against this, but it still is an extra step that you need to be aware of.
• Table overhang is still a thing with these vices.
• If you really tighten them the base of the vice will deflect upwards in the middle. This is true of any vice, but other vices will deflect the rear jaw long before this happens so it's less apparent. You need to ensure the base of the vice is fixed down in the middle rather than at either end.
• Gerardi are fully rigid, while other makes (Komtas) have a reversible moving jaw carrier that will allow the moving jaw to be either rigid or with lateral rotation. This means that Gerardis and those like them are really not good at clamping parts that aren't perfectly parallel.
• Soft jaws are pretty much not a thing on wedge jaw vices, unless you use an intermediate hard carrier jaw. They do usually have a pretty good range of application jaws.
• It's easy to set up two wedge jaw vices as a split vice for large workpieces, by mounting them end to end and reversing the moving jaw. The fixed jaw is usually removable too if need be.

In summary, wedge jaw vices require more care and cleanliness during part changeover, and are not ideally suited for first ops on raw material. On the other hand, they are far superior in terms of squareness, parallelism, pulldown, and clamping security, so are great for secondary ops where accuracy is paramount.

The part about parallelism and square is not accurate. A wedge jaw that does not pull down perfectly parallel to the base Is inherently neither square or parallel. There is a reason why toolroom's use fixed jaw vices for high precision work.

 

[???]

Another option is a large grinding vice high precision and quick to change the opening size. Clamp screw is at an angle so access is easy.

I am currently replacing all my Gerardi style vices with grinding vices.

 

[gregormarwick]

The part about parallelism and square is not accurate. A wedge jaw that does not pull down perfectly parallel to the base Is inherently neither square or parallel. There is a reason why toolroom's use fixed jaw vices for high precision work.

It is accurate, but depends entirely on the user to keep them clean, which is why I always labour that point when discussing these vices.

If you don’t keep them clean they won’t pull down parallel, if you do, they will.

 

[usolutions]

The part about parallelism and square is not accurate. A wedge jaw that does not pull down perfectly parallel to the base Is inherently neither square or parallel. There is a reason why toolroom's use fixed jaw vices for high precision work.

Local toolroom for sheet metal stamping facility that make dies in house use gerardi's for their high precision work, and was recommended to get them, thus prompting this thread.

Have a nice day.

Sorry if i my reply was rough or offensive, was not the intent.

 

[EPAIII]

What style? One pushes down from above, NO BEHIND the movable jaw and the other pulls down from below it.

OK, the devil is always in the details so YMMV, but pushing from roughly the vertical center of the movable jaw is precisely what causes jaw lift in the first place. This is so common on the inexpensive, drill press style vises.

Now, if you add a slope there (at the vertical center of the movable jaw) it will try to push that jaw down. And that will change the action, but just HOW MUCH. It seems to me that it is the screw itself that the downward force on the jaw of the Gerardi style is pushing against. The tip of that screw if being pushed in an upward direction and the threads of the screw must resist that force as well as the forward force due to tightening. Is this good? I don't know. There is the possibility of extra wear on the thread. But, as I said, the devil is in the details.

OTOH, pushing the movable jaw (actually a separate piece) from below changes the fundamental geometry of those drill press style vises. But it does still try to rotate the movable jaw and that will move it's jaw upwards. PULLING it down and pushing forward with a wedge that is roughly at the vertical center of the movable jaw or just a bit below will reduce that rotation and jaw lift. This seems to be the more traditional and more frequently used method. I have two vises that are Kurt clones and it seems to work well. But I suspect even the Kurts and other high end vises with this design still have a bit of jaw lift. Probably on both jaws, not just the movable jaw. And I suspect that the Gerardis also have this problem.

Since both designs seem to apply the force to the movable jaw in roughly the same location and with roughly the same slope method, I do not know if there is any big difference from a design point of view. It would seem that it would be easier to keep the Kurt style clean of chips and that could be an advantage in a working shop. And the screw may wear on the Gerardi more rapidly.

But, as I said, the devil is in the details and you are asking about the general styles. It is entirely possible for the genuine Kurt vs. genuine Gerardi contest to be won one way while a contest with clones may go the other way. Details, details, details!

Gerardi seems to advertise a lot about modularity and accessories. And they seem to have quite a number of accessories. But, from what I can tell, the Kurt style is also quite modular and there are a number of accessories that can be purchased for them. I am not convinced that it is anything more than advertising blunder.

One thing that puzzles me is the Gerardi wedge shaped jaws. They make different models that take either standard(?) rectangular or wedge shaped jaws. But just what is the advantage of the wedge shaped jaw. Other than being more expensive and locking the buyer into just one source for additional jaws?

I could not afford a high end milling vise. What I did buy was not one, but two imports from a good dealer (IMHO)(Shars). They are finished overall to around +/-0.0005" to +/-0.0008" and match each other to that level as well. I can easily do work to +/-0.001" with them and better if I take some care in the set-ups. Perhaps not as good as Kurt or Gerardi, but you can get clones that are good for general work. And the two of them cost just a bit over half what a Kurt would have. I even got a swivel base with one of them.

I am more about what type to get, not exact make and model.
As example I can get:

Simply buy Modular vice 150/2 mm | Hoffmann Group

Buy Modular vice 150/2 mm at the Hoffmann Group eShop: ✓ Personal advice ✓ Exclusive top products

www.hoffmann-group.com

Simply buy Stationary machine vice 150M | Hoffmann Group

Buy Stationary machine vice 150M at the Hoffmann Group eShop: ✓ Personal advice ✓ Exclusive top products

www.hoffmann-group.com

Roughly same price, roughly same opening, same decent quality brand. Being all basic parameters equal, which is better and why, this is the question I have.

 

[Philabuster]

Often a flex head bent handle ratchet can be the answer.

I love my bent handle flex head ratchets! That's the first tool I grab when I am wrenching on stuff. In my case, I needed a bit more leverage to wind out the 15" 3-jaw chuck so the speed wrench was the answer for me. I do use a bent head flex ratchet on the 6" Hardinge chuck though. Much faster than a T-handle.

 

[gregormarwick]

...

Lots of misconceptions in this post. The wedge jaw style vices have a prismatic retainer under the moving jaw, think like a big precision tee slot, that provides the opposing force to the pull down action, not the screw.

The purpose of the wedge jaws is to pull the part down. On a Kurt style vice this is done by pulling the whole moving jaw down against the nut and ignoring whatever deflection exists on the rear jaw. Wedge jaws pull the part down much more reliably.

 

[EPAIII]

It's late and no time to rethink my post. One thing is that the OP was not talking about getting either a Kurt or a Gerardi. He seemed to be talking about getting some other, possibly less expensive brand in one of those two styles. And perhaps not made with 20 micron accuracy as claimed in one Gerardi video. That was my vantage point. And I am not sure I want to change it.

One thing I am pretty sure of is that both of those brands would be a lot better than what I presently have. Oh, and while there are many Kurt knockoffs, I am not even sure I have seen any other brands that are made in the style of the Gerardis.

Perhaps tomorrow.

Lots of misconceptions in this post. The wedge jaw style vices have a prismatic retainer under the moving jaw, think like a big precision tee slot, that provides the opposing force to the pull down action, not the screw.

The purpose of the wedge jaws is to pull the part down. On a Kurt style vice this is done by pulling the whole moving jaw down against the nut and ignoring whatever deflection exists on the rear jaw. Wedge jaws pull the part down much more reliably.

 

[gregormarwick]

It's late and no time to rethink my post. One thing is that the OP was not talking about getting either a Kurt or a Gerardi. He seemed to be talking about getting some other, possibly less expensive brand in one of those two styles. And perhaps not made with 20 micron accuracy as claimed in one Gerardi video. That was my vantage point. And I am not sure I want to change it.

One thing I am pretty sure of is that both of those brands would be a lot better than what I presently have. Oh, and while there are many Kurt knockoffs, I am not even sure I have seen any other brands that are made in the style of the Gerardis.

Perhaps tomorrow.

I wasn't being critical of what you wrote, simply pointing out some misunderstandings you seemed to have about the way the Gerardi type vices work. It seems to me that this kind of vice is pretty uncommon outside of europe, but there are quite a few who make them here. Chinese copies also exist as another member pointed out.

Kurt style vices appear to me FAR more common in the US, and I was always outspoken about my disdain for Kurt vices in particular, until it was pointed out to me by another member here that they are about half the price of an equivalent size Gerardi. Horses for courses.

 

[usolutions]

One thing I am pretty sure of is that both of those brands would be a lot better than what I presently have. Oh, and while there are many Kurt knockoffs, I am not even sure I have seen any other brands that are made in the style of the Gerardis.

I am considering getting two sets of these

Double-Action Precision Machine Vise 125MM FPZD125/2x100 DARMET

✔️ Jaw width: 125 mm ✔️ Jaw opening: 2x100 mm ✔️ Jaw height: 40 mm ☎️ 0048 85 653 86 70

toolsmach.com

This is Darmet, have seen their lathe chucks, nothing bad can say. Am not sure if they produce exactly these, or import, but their reputation suggests reasonable quality. They do definetly produce some of their stuff in Poland, as have done since cold war

 

[twr]

I have a gerardi double station like you just posted but i moved the center jaw to the back and use it as a single vise. It allows me to hold large parts. Its mounted beside a 12" single gerardi they work very well!! I may move 2 clamps more to the middle from the end after reading that gregormarwick thanks! They replaced 2 kurts, that turning the kurts handle from a 1" part to a 5" part sucked.

​

 

[EmGo]

I do use a bent head flex ratchet on the 6" Hardinge chuck though. Much faster than a T-handle.

Do you have a ratchet on your t-handle ? mikey likes it.

 

[empower]

I think Orange vise would be good option for, if it was price comparable with kurt or basic gerardi of about 600-1300 per unit depending on size and composition. I have no doubts that OV worth every penny, but money does not flow here as freely as in California. Unless there would be super duper sale on black friday, but I am afraid I would not be able to wait that long.

In my case it should be plenty enough repeatable.

Haas has 6"x12" gerardi style for 649. About same money as other european suppliers.

i dont know about gerardi quality, never used one personally, but if you're gonna buy a haas vice, dont expect quality. you get what you pay for.
i would reach out to eric @Orange Vise and see if he'll cut you a deal, the guys are really great to work with and good people, and most importantly, a TOP NOTCH product. been using their stuff for 5+ years and i beat the shit out of them, they're indestructable.