In precision machining, a self-centering vise is a valuable tool that enhances accuracy and efficiency. This type of vise automatically adjusts to position the workpiece at the center, ensuring that each setup is perfectly aligned. Self-centering vises are essential for applications where symmetry and consistency are critical, such as in CNC machining, metalworking, and various assembly processes. One of the key features of self-centering vises is their compatibility with different types of jaws, each serving a unique purpose. In this article, we’ll explore five types of jaws compatible with self-centering vises—high type jaw, low type jaw, jagged jaw, soft jaw, and V jaw—and how to select the right jaw type for your application.
You can find more information on our web, so please take a look.
A self-centering vise is designed to automatically center workpieces, making it ideal for operations requiring high precision. Unlike standard vises, which require manual adjustments, a self-centering vise uses a mechanism to ensure that the workpiece remains centered regardless of its size. This feature makes it especially useful in CNC milling, where maintaining a consistent center point is essential for producing accurate and repeatable results. Self-centering vises are also widely used in tasks that involve rotational symmetry or require multi-sided machining, as they allow for precise positioning and repeatability across multiple setups.
Self-centering vises are used in a wide range of applications, including:
The versatility of self-centering vises makes them suitable for numerous industries, including automotive, aerospace, electronics, and medical device manufacturing. Each application may call for different jaw types, depending on the material, shape, and stability required for the workpiece.
The choice of jaw type is crucial in ensuring the vise’s performance matches the specific needs of the workpiece and machining process. Here’s a breakdown of the five types of jaws and how to choose the right one for your application:
1. High Type Jaw
High type jaws are ideal for holding taller or larger workpieces securely. They offer greater surface area for clamping and provide more vertical support, which helps to stabilize large parts during machining. This jaw type is beneficial when working on parts that have a considerable height, as it allows for better grip and reduces the risk of slippage.
2. Low Type Jaw
Low type jaws are designed for clamping shorter or smaller workpieces close to the vise base. They provide stability and minimize the distance between the clamping area and the work surface, which is particularly useful for low-profile machining tasks. This jaw type allows for increased accuracy when working with compact parts and offers better visibility of the workpiece.
3. Jagged Jaw
Jagged jaws have serrated edges that offer an enhanced grip on the workpiece. These jaws are particularly effective for holding rough or irregularly shaped materials, as the serrations “bite” into the material, preventing it from shifting during machining. Jagged jaws are ideal for jobs requiring a secure hold on tough materials that might otherwise slip or move.
4. Soft Jaw
Soft jaws are made from softer materials, such as aluminum or mild steel, that can be machined to fit the exact shape of the workpiece. These jaws are highly customizable, allowing operators to create a form-fit around the workpiece. Soft jaws are ideal for delicate materials or precision components that could be damaged by harder jaws.
5. V Jaw
V jaws are designed with a V-shaped groove that enables them to hold round or cylindrical workpieces securely. This design helps to position round parts precisely at the center of the vise, making it ideal for machining or drilling operations that involve cylindrical shapes. V jaws are particularly useful for tasks where the part needs to be centered with high accuracy.
When selecting the right jaw type for your self-centering vise, consider the following factors:
Self-centering vises offer a versatile and efficient solution for holding workpieces securely, with minimal setup adjustments. The choice of jaw type is critical in achieving the desired clamping strength, stability, and accuracy needed for your application. By understanding the unique functions of high type, low type, jagged, soft, and V jaws, manufacturers can optimize their machining processes, reduce setup times, and ensure consistent quality.
I have a small one Vic – it's a good solid small vice and seems well made but frankly I've never used the self-centring aspect of it as such, although it might be useful.
For instance my small Taig head has a ER16 collet (max 10mm). So in theory I could hold a 10mm rod in the collet, grip it in the vice, then bolt the vice in position and then place (say) a 30mm piece in the vice and it would be 'automatically' centred.
I'm not sure how accurate this would be in practice though. Probably in the "near enough" category for most things I would think but I don't know for sure. I guess I'll have to test it now…
Regards,
IanT
I don't see it would help at all unless I'm missing something. For a start you lose the benifit of a reference jaw you get with a standard milling vice. With a clocked Jaw corner and a DRO you can quickly reference a workpiece and Drill or machine wherever you choose.
With competitive price and timely delivery, NEXTAS sincerely hope to be your supplier and partner.
As I said please tell me if I have missed something.
regards Martin
Presumably you get a reference centre instead of an edge which I, for one, would find useful in some circumstances. There are several ways to do any job. Everyone has their own preference(s) but it's usually worth keeping an open mind.
I've looked at self-centering vices and – like others I suppose – wondered just how accurate they are. It would be nice to have a feel for that.
If a job needs the accuracy then I work off the fixed jaw. Some jobs though are “near enough” in this case if I want for example to centre drill a 12mm rod I’ll put a 12mm piece of short stock in the Chuck and then move the vice until it just touches the bar. I can then replace the bar with a drill bit and drill the hole. This is pretty quick and pretty accurate. Sometimes though the piece to be drilled is not a size, often too big, that I can put in the Chuck. If the SCV is reasonably well made (I’m not sure it necessarily would be) then it could come in handy for any size up to its max capacity.
The CNC boys love them, Ideal if machining all around a rough block, if it's size varies you still take equal amounts off both sides. As with everything what you pay is what you get and the CNC ones come out more expensive than say the Warco offering.
Unless there is a need to machine a varying range of parts centrally without disturbing the vice I don't see much use for them otherwise.
The hardened jaws have small "teeth" that actually bite into the work or another option is to pre machine a small dovetail along two sides of the blank. Once all 4 sides and the top have been machined the part will then often go into a second vice with custom nesting jaws that grip the machined shape of the part which is then decked to remove the waste from the bottom and do any other machining on that side which removes the jaw marks from the second operation.
You can buy replacement jaws for your "Kurt" clone type vice that will take the hardend serrated jaws if you can't stretch to a full blown CNC vice.
Also worth noting the vices are quiet tall which is to allow all round access when using a 5 axis machine.
They come under the heading of gimmicks as far as I'm concerned since you can't beat a fixed jaw to ref to in all 3 axis, then you know where you are. As said above, heavily dependent on the accuracy of not one but two leadscrew threads, two moving jaws with the possibility of both rising up (probably by varying amounts) as the are tightened. Good idea at first sight but fails on many points. Even if made to 'aero' tolerances, wear would soon put paid to manufacturing accuracy. Not got one, dont want one, not even free gift. Likely to be more trouble than it's worth and I'm too long in the tooth therefore lacking strength to loose my rag and chuck it over the hedge!
Peter,
Kurt supposed to be one of the better makes of vises but even they probably have their limits. Impressive accuracy quoted. Imports from the cheap labour areas of the World will always trail a long way behind as also rans. Trouble is, people who cannot afford quality become dazzled by low prices and buy and later regret it. My prefence as previously stated, is for a fixed jaw to use as a datum.
For the way they are used for CNC work you are not bothered by having a back, side and bottom ref hence they are ideal. Probing will get the block set to a ref by averaging out the two sides, front/back and top. You then machine all 5 exposed surfaces.
Remember this video everyone thought was great a couple of months back for trueing up 5 surfaces on a manual mill, its the same method that the CNC does.
So to sum up so far then, the are more use on CNC when working from unmachined blocks, can be of good quality like the Kurt but if you have a fixed jaw vice already may not really add enough to warrent an additional vice.
No one has talked about capacity. Do they not tend to be bigger workpiece wise for similar footprint and I seem to recall better anti lift performance on the jaws?
regards Martin
If you are looking for more details, kindly visit Self Centering Vise.