Which Kurt Vise to get for CNC

[JMFabrications]

I just bought a used 3 axis CNC vertical mill that is being delivered sometime next week. I wanted to order a few things ahead of time so I can be ready to cut when this thing gets here. This will be my first CNC mill so Im anxious to use it. From what I read the Kurt vises are the best. Enco says the 3600V is recommended for CNC machining, but the opening is only 6". I was looking at the D688 which has an 8" opening, but Im not sure if its the best choice for CNC, Id like to have at least an 8" opening without spending $1k on a vice. I see alot of setups that run 2 vises to hold longer material, at what lenght do you recommend using a 2nd vise? Any input on this would be greatly appreciated.

Thanks,
Jim

[mxtras]

Kurt may be the best, but some of the knock offs are very suitable and cost less than 30% of the Kurt. A 6" Kurt is - what - $600? A 6" Enco is $150ish? I don't know - but I think I would consider it - if you don't like it for some reason, sell it and get a Kurt but to get going, you are going to need lots of tooling and lots of other things - maybe research the knock-offs and save yourself some $$ now. You can get the Kurt when you complete your purchasing binge....unless you have ample cash. I don't know your situation.

I have been using an Enco for quite a while and I have used countless Kurts in the past. There is a difference but the Enco is suitable in my opinion. Some may argue that - so lets hear it....

Scott

[DareBee]

I have used a few Kurt knock-offs, the differences are very subtle, but for longevity and satisfaction nothing beats the Kurt (that I have seen). It is all I will buy anymore, period.
I use a D688 on my VMC and am happy, the vise you chose needs to suit YOUR requirements. For my job shop I need nothing special. For production or super high precision a 688 shouldn't be your first choice.

[WayneHill]

The jaws can be placed on the outside of the slide and the stationary for a larger holding area.

A Kurt vice will last the life of the machine and more.

Don't scrimp on the vice. Buy a Kurt or Chick. Leave the
cheap vices on the store shelfs.

[ViperTX]

Besides when you buy a Kurt the $90 or so to ship it doesn't sound bad....when I buy my cheap vise (Phase II or Enco).....the shipping is as much as the vise and that feels bad....

Also the CNC vises have features which allow you to stack them, accurately place and remove them....etc.

[kmbx]

as far as holding longer work pieces you can just make your own jaws at any length
used both kurt and knock-offs for 15 yrs. yes the kurt holds up better but its like buying a caddy or a geo metro they both get you from point a to z.

[One of Many]

A few comments on the larger opening vises and multiples.

It is not that all of the imports are weak or wear faster, but whether they are precision as far as square and parallel that counts. That can be a crap shoot and a questionable gamble at best. Even more so if you intend on buying more than one.

The Kurts are work horse, that is for sure. If you plan on using more than one, you might consider a matched pair(or match them yourself). Otherwise, I have seen them differeing in base height. Then there is the fixed jaw and jaw thickness, that can have some tolerance issues that may offset them IF you intend to use the T slot keys.

The larger opening vises do have the screw casting protruding out the back below the fixed jaw until it is open a couple inches. On narrower tables this forces them to be mounted toward the front of the table so there is no interference with the Z axis ways or column dovetails. I've seen operators run a program and wipe out the ways behind the table and believe me it can do serious costly damage to the rails, way covers, vises, table or anything else in the mix.

Distance between 2 vises is normally as needed for the present operation. Not as hard on mills with bearing rail ways, but the added weight over the long term on sliding member machines will induce additional wear on constant extreme travels. After a while, the wear from the over hung weight can make machining flat surfaces impossible. Primarily the reason most mills are only given a tolerance spec over the saddle anyway, but you get the idea of what is at stake for the convenience of multiple vises.

DC

[JMFabrications]

Thanks guys for all your help... I ended up getting the Kurt D688 to start, if I dont like it, I can always upgrade. My CNC machine is scheduled to arrive Monday, cant wait to use it.

Thanks again,
Jim

[jed102]

Hello Jim,

I just bought a d675 and noticed that there is a lot of side to side movment on the movable jaw, in fact 0.024 inch. Could you please let me know how much you have in your vise as I would like to see if this is normal for Kurt. I spent the big bucks to get precision, so I am not too impressed.

Frank

[Gads]

Hi I notice you purchased already I was going to recommend looking into a kurt DL double lock vise or clone. I have a small Dl and it allows you to have
a large choice of setups and or multiple work locations as well as being able to be set on side or end etc. with great accuracy.

As for the slop in the movable jaw you want slop if you look at how a kurt vise works they have a wedge between the jaw and the screw that pulls the jaw down as you tighten the part and the slop allows for some squareness variation. most kurts have an allen adjustment on the back side of the movable jaw section that allows you to adjust just how much slop is in the jaw.
my experience with kurt vises has proven they are well worth the money..
Gads

[jed102]

Yes Gads, you are right about the allen key adjustment for the up and down aspec, but it doesn't help the situation in regards to grabbing certain small parts that are easier to work with on one side of the vise.

I may end up making some modifications to allow for adjusting the amount of side to side slop for different situations. It does seem that it isn't a real big concern to some, and thanks for your thoughts.

Frank

[dertsap]

Originally Posted by jed102 Yes Gads, you are right about the allen key adjustment for the up and down aspec, but it doesn't help the situation in regards to grabbing certain small parts that are easier to work with on one side of the vise. Frank

put a dummy part on the othe side of the vise