Fixture Plate Question

Blackdiamond · Aug 23, 2012

So I am making a semi quick change fixture pallet system for my Haas super mini mill. My table size is 16" X 12". I ordered 14" X12" X 1" thick MIC-6 aluminum plate for the project. I would have gotten bigger than the travel range, but I wanted to leave my Renishaw tool setter on the table.

What type of locating pins would you suggest? I have seen the combination of diamond and round pins in many of the pictures I found. What size pins should I use, and how many? Also, would it be better to just use the two Kurts and clamp the plates with both vices?

I would love to order ball locks or some fancy quick change fasteners, however, I think I'm going to go with standard 1/2" screws of some type. I have the probe, and if something doesn't locate precisely, I could always adjust. I am planning on having 3-5 plates, with my vices mounted on one of them.

Any suggestions or feedback would be great.

kevkess · Aug 23, 2012

Check out Jergen's Work Holding Systems. They make everything you are describing. I have used them in the past for quick locating dedicated fixturing.

ewlsey · Aug 23, 2012

Does your table have a slot going in the "Y" direction?

Sine keys are a pretty simple way of locating fixtures to the machine table. If the slots are in good condition, you can hold a few .001s. There are several kinds of keys, some fit in a reamed hole, some in a slot.

What is your expectation of tolerance/repeatability? You might be surprised how loose the tolerance is on Mic-6 plate. It is also pretty soft, even on aluminum terms, so it will not last forever.

Blanchard ground steel plate is kind of the industry standard for things like this. In the sizes you are talking about, it might actually be cheaper than Mic-6.

tc1999 · Aug 23, 2012

You can get a long lifespan out of a MIC 6 plate. Mine is pretty much dead flat after 6 years of use...Last shop I was at has MIC 6 plates on their machines that are decades old.

D Dubeau · Aug 23, 2012

We use a lot of mic 6. I just unloaded 2 4x8' sheet's of it this morning. It lasts, but it all depends on how you treat it. For high use stuff, we get it hard anodized, but for 1 off, and low use just use as is. If you're slamming them on and off the table, in a "every second counts" type scenario, I would choose another more suitable material.

escott · Aug 23, 2012

We used speed loc fasteners for ours and have been very happy with them. 4 per plate, as manufacturer recommends.
As to Blanchard ground plate they can vary by quite a bit in thickness/parallel. You really can't probe your way out of the vise bed being not parallel to the table. If it were my plates I wouldn't rely on Blanchard ground. If it needs to be flat it needs to be flat. Mic6 plate usually needs a skim to make it flat as well.

ewlsey · Aug 23, 2012

escott said:
We used speed loc fasteners for ours and have been very happy with them. 4 per plate, as manufacturer recommends.
As to Blanchard ground plate they can vary by quite a bit in thickness/parallel. You really can't probe your way out of the vise bed being not parallel to the table. If it were my plates I wouldn't rely on Blanchard ground. If it needs to be flat it needs to be flat. Mic6 plate usually needs a skim to make it flat as well.

Who are you having do your grinding? A blanchard could hold .001 on flatness and parallel on the size plate we are talking about. MIC 6 is supposed to be .005, but I've seen more than twice that.

Blackdiamond · Aug 23, 2012

My slots are in good shape. Got my machine new in January. Jergens stuff looks great, the problem is the heads on all their ball locks and pins are giant. Not to mention their stuff is expensive. I should be able to get within .005" as long as I square off everything and make sure my pins are positioned right. I don't need them to last more than a year or maybe two. I will be using mitee bites, and other methods of clamping on the plates. one plate will have a vise or two, so if I need a bit more rigidity, I can get it. I'm by no means the expert here, but these plates are for parts I'm currently holding in 6061 soft jaw, and I think the Mic-6 should be sufficient. The link below is more of what I'm looking to do. I will probably use a different type of fastener on top. Any idea wha size those locating pins might be?

Mitee Bite Clamps and Shopmade Pallet Fixture for Small Parts « CNCCookbook CNC Blog CNCCookbook CNC Blog

Alberic · Aug 24, 2012

We've got Jurgens ball-locks on our Daewoo, and it's saved our tails more often than I can count. Well worth the money. The carrier plates repeat to within .001" without even trying, even when they're cranking down a plate with 3 Kurt 645's on it. You can make your own carrier plates, but I'd buy a master plate from Jurgens. Yeah, it's pricey, but it lets you change out jigs in seconds without worrying too much about location. Yes, the Jurgens heads are giant. Nature of the beast I'm afraid.

Blackdiamond · Aug 24, 2012

Thanks for the feedback.

What size and shape locating pins would you recommend for a 14"x12"x1" plate?

Brian · Aug 24, 2012

I would use .500 diameter locating pins on that size... I made a plate system for a 40x20 machine years ago and think we used 3/4" at the time.... but the plates were more like 16" x 24". We had a job that repeated with 4000 pcs. per month, we were able to load like 40 some parts on the plates each load. We did use blanchard ground steel plate for the sub base, and steel plate that we hollowed out with pockets underneath for the changeable plates... although Mic 6 would have been sufficient, and easier on the operator.

To hold the plates in alignment we used the identical situation you linked to, one round, one diamond pin and location was always within tenths.

LOCATORS, LOCATING PINS, Bullet-Nose Pins :: Carr Lane Manufacturing Co.

To hold the plates down, we used hydraulic clamps, they are sold by Carr-Lane and are actually built by Rohmheld, these aren't exactly like them, but the closest I could find (I built mine 20+ years ago, so they might not have the exact same units):

SWIFTSURE

We had an air over hydraulic power unit and wired in a relay for air blast to the unit and could M-code the clamp/unclamp portion of the process. It all worked great until the customers needs went from 4000 to 6000 per month to about that amount twice a year....

escott · Aug 24, 2012

ewlsey said:
Who are you having do your grinding? A blanchard could hold .001 on flatness and parallel on the size plate we are talking about. MIC 6 is supposed to be .005, but I've seen more than twice that.

Key word "could". Get a blanchard ground plate from a common supplier, throw it on a surface plate and actually measure it. I'm aware of what can be held, but I also trust my indicator.

ewlsey · Aug 24, 2012

escott said:
Key word "could". Get a blanchard ground plate from a common supplier, throw it on a surface plate and actually measure it. I'm aware of what can be held, but I also trust my indicator.

What is your "common supplier?

All I know is that if I buy a flame cut 1" or thicker plate, get it stress relieved, and take it to my local grinder, it comes back to me within .0015/12 on flatness and parallel up to 40" corner to corner.

I can have the flame cut made in any shape, with windows and complex curves. The MIC-6 has to be milled or cut on a plate saw (possibly water jet, but that will cost you). I have milled some and it pretty much sucks to machine. It is very gummy and soft.

The only time I use MIC-6 is for leak test fixtures where I need corrosion resistance and no real strength.

Blackdiamond · Aug 24, 2012

Brian,

Thanks for the great answer. Sometimes I think it's a guys compete on who provides the best answer. The info I was looking for was pretty simple, except I didn't really know because of all the other input I had received. The parts being machined are .2" thick and will be held with mitee bites. Using steel would be great, but, unnecessary for this application. I will be surfacing and pocketing .01-.04" deep and I don't need them to be able to clamp the empire state building

. I'll post pictures when I get it done. (even though they will be criticized, cause everyone has their own opinion, and someone will always do it different

Thanks for all the info guys.

Brian · Aug 24, 2012

No problem, just been there, done that... and this was back in the day (probably late 80's) when the commercially available pallet changers were non-existent. It works well, and can really speed things up if you have repeat jobs... we made other fixture plates and used the same base unit on the mill quite a bit.... although it was really too large for manually putting plates in and out. I could see a smaller version being very handy.

PaulT · Aug 24, 2012

If you are bucks down, if you search "subplate" on this forum you'll hit a lot of good suggestions on making your own subplates and pallets using standard tooling components.

I like and "borrowed" the suggestion that ARB made in the thread below to use a plate with a grid of tapped holes with a bored top so that you can use standard shoulder bolts to both locate and clamp fixtures and pallets.

http://www.practicalmachinist.com/vb/cnc-machining/subplates-118373/

Paul T.
Power Technology

Search

Largest Manufacturing Technology Community on the Web

Search

Fixture Plate Question

Blackdiamond

Aluminum

kevkess

Plastic

ewlsey

Diamond

tc1999

Hot Rolled

D Dubeau

Hot Rolled

escott

Aluminum

ewlsey

Diamond

Blackdiamond

Aluminum

Alberic

Cast Iron

Blackdiamond

Aluminum

Brian

Stainless

escott

Aluminum

ewlsey

Diamond

Blackdiamond

Aluminum

Brian

Stainless

PaulT

Stainless

Similar threads