Pros, Cons, Mounting vises on raised sub plate

[Roger]

What do you think about this? Rigidity? Accuracy?

 

http://i404.photobuc...zpsf9eb8e37.jpg

 

http://i404.photobucket.com/albums/pp129/rdantesbattleground/SUBPLATEWITH4VISES_zps52bbe4dc.jpg

 

I wanted to know your opinions on doing this. The sub plate will weigh 286 pounds, and I don't want to be putting it in, and out all the time. Anyone else do this?

[Guest]

I would never raise a sub plate up like that. Direct to the table only

 

In my opinion, you're going to have rigidity issues

[GoetzInd]

We have a similar set up on all our VMC's. Is there a reason it is so far off the table? ours is about .5 in. off and we can clear chips from under it.

 

Mike.

[Roger]

My reason is, this if a Haas VF5 SS. Nose of spindle to table at lowest point 7" (All their other machines go to 4", I think). The job's I planed running on it would be contouring jobs where I could use standard length tooling, and cut down into the plate. The current job I'm going to run is 3/16" thick ABS plastic sheet, part dimensions .950" x .660" with .093 dia. holes, I'm to get as many parts from the material that was provided, would allow ( which if I use a 1/8" end mill will yield 330 parts).

 

So, your replies, would be NOT run the vises on top, or NOT run ANY job on it, this high??? (7 1/2")

 

Thanks for your replies.

[Guyinthedesert]

I think you would find your set up much more rigid if it had a bottom plate, so it formed a box, and all the joints were welded, not bolted. We used to have the same problem where I used to work. The larger 50 taper machines wouldn't go low enough. Also, with a table like that, you have the luxury of being able to bolt things down from underneath.

 

On the downside, we all hate riser plates with tapped holes in them. Nothing beats a T slot. We bought several Haas mills that came with Chick setups. Everybody got so fed up with their riser plates they all ended up in a chip can.

[civiceg]

I have had to jack vises up on strips of 1" x 4" stock before, ideal no, but it was temporary and got the jobs done. The main reason I have had to jack vises up is to get clearance when next to a rotary table. Solid 4 inch plates for each vise work great, block keyed to the table and the vises keyed to the block. For the job you mentioned, that setup above is plenty rigid enough

[Sticky]

I wouldn't be worried about rigidity of that setup for anything that is going to fit in the vices. As long as everything was flat and doweled when assembled you will be fine.

 

I have a few 4 sided aluminum tombstones that are less then 1" thick, 15" across and 26" tall, and I can use a 2" U drill plowing through 304 stainless at the top of the stone without any issues.

[Thad]

Hijack: Who's the guy in the desert fatigues at your photobucket account? Looks like Desert Storm.

[gcode]

I'd add some stiffeners between the rails.

That would stiffen that riser up a bunch.

AS is, it's OK for light drilling but I wouldn't do any serious milling with that setup

[Roger]

Thad,

 

That would be me. And you are correct, Desert Storm. I was with 101st Airborne in that photo. (Screaming Eagles)! My son is currently station with them. He's in supply now, assigned to the SF group there. I got to visit him in April. He showed me their arms room, and all the neat "toys"!!

[TK-32™]

I was working in a mold shop were they had plates like that. At first I was so worried that I indicated everything after roughing. Thing never moved. The optirough toolpaths help. It's one of those things that you won't know until you try it.

[Newbeeee™]

I'd add stiffeners between as G.

Other than that I'd have used 2" ally and you could always have put 1/2" gauge/wear strips on the top

[5th Axis]

It looks like it should hold up okay, I would have gone with some small self centering vises and risers. More for repeatability purposes than anything.

[gary adams]

We did similar on a machine with a nose to table issue. Problem was the sub plate plus packers added table weight and with the addition of our 4th axis, that we left constantly mounted, we found every couple of years we were replacing the angular contact bearings that anchor the ball screw. The machine is almost redundant now, but the benefits were outweighed by the negatives in our case.

[cunder]

We have a similar sub plate but a little smaller in size. Have no trouble with. The difference is is made with 7075 aluminum.

[taperlength]

It looks okay to me. I did have a problem a while back, a dulled 1" HSS endmill in steel pushed a subplate .010 out of whack. But it should be good for most else.

[P B]

We run sacrificial slave tables 1.25" thick steel (30mm proper language) on 6 pillars and back bolt jobs onto it. You can put multiple blocks up and finish the outsides completely (no vice jaws or clamps to hit). I bolt a vice on to slave table to face / chamfer / drill and tap etc.Then bolt the job down and go for it. When the table is full of holes replace and start again. Don't have any problems with moving or rigidity, but they are not large machines (800mm x 400mm) verticals