You are a great teacher. Your pace and quality of explanation are such that I am able to predict each word you are about to say in my own mind just a split second before you say it.
Vacuum is great. No work holding to hit with the bit, no worry about movement if set up properly, and nothing physicaly holding the part down, except air, so you can release it with a flick of a switch. So easy.
@PiersonWorkholding Haha especially if you need to machine 20 microns off of a 100 micron foil. Yes, an uninterrupted grid of stepped (small diameter at the surface, not to suck dimples in the foil) holes and a channel system in the base plate. Air pump more designed for flow than pressure, because of leakage (no gasket indeed). So nice if you can get it right. Seems simple, but has many aspects, as you demonstrated in your video :))
The BEST tip I got was to leave a skin on all features until the end to maximize the full force, then do a finish pass to pierce through; very clever. You said the 0.125 it the general preference but could you mix gaskets, say use 0.125, but also 0.063 for small inner features, still using the 80/95 formula?
Mixing gaskets is possible but not recommended only because it's tricky to get the top crest of the gaskets to be flush with the bottom of the part. Inevitably, you'll need to press down on the part to get it to contact the different tops of both gasket sizes to get the part to seal. Again, possibly but the gains aren't too significant.
I'm curious if any of your customers at higher altitudes have noticed lower holding power? Before machining I did composites and when vacuum bagging we had to calculate our theoretical max psi as you lose .4 psi per 1000 ft of elevation. It may not sound like much but at 5000 ft where I'm at in Utah that's near 2 psi give or take.
@@LoneWolfPrecisionLLC we are at 5600’ and had to get creative in our op2 when the parts are split. Using the textured landing pads from McMaster Jay uses on his PPS plates, Harvey down cut end mills, and light step overs gets us a thousand parts per month on our Pierson vacuum fixture.
Yes, altitude definitely has an effect on the maximum vacuum level. Call it roughly 0.5 psi of downward holding force less per 1,000 ft of elevation gain.
@@PiersonWorkholding okay. only asked since i dont really have any experience with vacuum workholding ( most of my experience is on lathe. and the mill experience was only in vise and screw down fixtures in vise ) and though that a ramp style would be perfect since a lot of the cutting force goes downwaerds instead of side ways ( whice vacuum holding is way weaker to then downweards/drilling )
It's impossible to give you a single number. The minimum surface area needs to be high enough to generate more holding force than that cutting forces applied to the part.
Not the only way, lots of factors to consider. If it was a production run then the expense of a vac table is justified but if that was a one or two off then i would just use double sided tape.
Agreed. If you have 1 or 2 parts to make, buying a vacuum system isn't necessary. Once you get to production quantities, custom vacuum fixtures are a great option.
✅ Buy a SmartVac System 👉 store.piersonworkholding.com/SmartVac-II_c_7.html
You are a great teacher. Your pace and quality of explanation are such that I am able to predict each word you are about to say in my own mind just a split second before you say it.
Vacuum is great. No work holding to hit with the bit, no worry about movement if set up properly, and nothing physicaly holding the part down, except air, so you can release it with a flick of a switch. So easy.
good video Mr pierson..thanks for your time
Thanks for watching.
That’s a very good video. Thank you Jay.
Glad it was helpful!
Awesome info by the way. I designed a few vacuum tables for thin foils; different, but deals with a lot of the same aspects.
Foils are tricky! Did you use a top surface with tons of holes and no gasket?
@PiersonWorkholding Haha especially if you need to machine 20 microns off of a 100 micron foil. Yes, an uninterrupted grid of stepped (small diameter at the surface, not to suck dimples in the foil) holes and a channel system in the base plate. Air pump more designed for flow than pressure, because of leakage (no gasket indeed). So nice if you can get it right. Seems simple, but has many aspects, as you demonstrated in your video :))
We're planning to put our vices and 4th axis on pallets, is there a black friday discount again this year? :)
The BEST tip I got was to leave a skin on all features until the end to maximize the full force, then do a finish pass to pierce through; very clever. You said the 0.125 it the general preference but could you mix gaskets, say use 0.125, but also 0.063 for small inner features, still using the 80/95 formula?
Mixing gaskets is possible but not recommended only because it's tricky to get the top crest of the gaskets to be flush with the bottom of the part. Inevitably, you'll need to press down on the part to get it to contact the different tops of both gasket sizes to get the part to seal. Again, possibly but the gains aren't too significant.
I'm curious if any of your customers at higher altitudes have noticed lower holding power? Before machining I did composites and when vacuum bagging we had to calculate our theoretical max psi as you lose .4 psi per 1000 ft of elevation. It may not sound like much but at 5000 ft where I'm at in Utah that's near 2 psi give or take.
@@LoneWolfPrecisionLLC we are at 5600’ and had to get creative in our op2 when the parts are split. Using the textured landing pads from McMaster Jay uses on his PPS plates, Harvey down cut end mills, and light step overs gets us a thousand parts per month on our Pierson vacuum fixture.
@mountaintacticalcompany good to hear! I don't have many parts that come across my desk that need vacuum so I was curious if altitude did affect it
Yes, altitude definitely has an effect on the maximum vacuum level. Call it roughly 0.5 psi of downward holding force less per 1,000 ft of elevation gain.
How do you calculate the pressure needed for the seals?
what about doing a ramp approach ? since it puts both side load and downwards preassure on the part well cutting
Yes, it's also useful to get to the bottom of windowed features.
@@PiersonWorkholding okay. only asked since i dont really have any experience with vacuum workholding ( most of my experience is on lathe. and the mill experience was only in vise and screw down fixtures in vise ) and though that a ramp style would be perfect since a lot of the cutting force goes downwaerds instead of side ways ( whice vacuum holding is way weaker to then downweards/drilling )
Is it possible to get models for the top plate? It would make designing fixtures easier.
Yes. Email us for a model after purchase and we'll send you one.
What is the minimum surface area you like to have for a vacuum system?
It's impossible to give you a single number. The minimum surface area needs to be high enough to generate more holding force than that cutting forces applied to the part.
Fixture Friday #27 is 27 minutes long? Easter egg or coincidence?😂
Totally planned 😂
Not the only way, lots of factors to consider. If it was a production run then the expense of a vac table is justified but if that was a one or two off then i would just use double sided tape.
Agreed. If you have 1 or 2 parts to make, buying a vacuum system isn't necessary. Once you get to production quantities, custom vacuum fixtures are a great option.
We want to see it in action, right on the machine