Plumbing a horizontal

[Josh Kinney -Elite Engineering]

Gents,

I'm wondering if anyone has a genius idea for how to get hoses to a rotary union on top of a tombstone?

 

I need to get air, vacuum and power to a tombstone in our HX500G and with 35" of z travel an articulating arm is not gonna work.

 

Here's the union I'm using http://www.scottrotaryseals.com/products/rotary-unions/ul/

 

I'm planning on using 0.040"x2" spring steel and letting it stretch when extended and loop when home. I'll run the stuff along the bottom. It will work but I'm open to better ideas!

 

Thanks,

 

Josh-

[civiceg]

Do you rotate the pallet in the home position? I feel like that would be your only snag. On horizontals we only have to run vacuum and use coiled air line to handle the z motion. 

 

We have a vertical with a pallet changer and rotary table. So it has vacuum, air, and wiring. It uses these http://www.ebay.com/sch/i.html?_odkw=plastic+condiut&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xplastic+cnc+wire.TRS1&_nkw=plastic+cnc+wire&_sacat=0

[Josh Kinney -Elite Engineering]

Yes we need to be able to zero return the b axis. We've used coils before but with two lines and a 6 wire cable spanning 35" of z travel gets problematic

[YoDoug®]

We do horizontals with 35" in of travel that have a double hinged arm. We use Waukesha tool or koma to do the setup.

[Josh Kinney -Elite Engineering]

Would love to see pics of a double hinge. Seems like it would slap upon zero return?

[jlw™]

I'd like to see pics too.

 

Straight up curiosity, what is the electricity and vacuum for?

[Master Mason]

I've been using this setup for about 10 years, works good with hydraulic line.

 

 

 

 

 

maybe use a cable wrap,

 

[robk]

Our horizontal Okuma in here uses the double hinge design. It's running a Koma setup.

[YoDoug®]

I am having a hard time finding a good picture of one we have done. However it is very similar to what Master Mason posted. 

[Josh Kinney -Elite Engineering]

I'd like to see pics too.

 

Straight up curiosity, what is the electricity and vacuum for?

Air pneumatic clamps, vacuum holding and vacuum switches to sense vacuum loss while machining.

[YoDoug®]

Air pneumatic clamps, vacuum holding and vacuum switches to sense vacuum loss while machining.

 

I'm curious as to why you would need to run switches inside the machine. If the fixture develops a vacuum leak/loss in the machine a sensor in the line outside the machine would register.

[Josh Kinney -Elite Engineering]

Not true. A 1/4" line can flow 7cfm. Same as my pump. I'm sensing vacuum directly at the part face independent of the vacuum line. Spinning a 6.5" face mill you wanna shut it down asap if you lose vacuum

[Josh Kinney -Elite Engineering]

And its built for future robot loading with a feedback loop to tell the robot the part has vacuum.

[Josh Kinney -Elite Engineering]

Here's the workholding. All built from scratch. 4 parts at once.

 

https://youtu.be/aPXEhvu8LfQ

[Josh Kinney -Elite Engineering]

 

 

[GoetzInd]

Cool beans. We do a lot of stuff w/ vacuum. Yeah, when you loose it, you want to know in a hurry haha.

 

Mike

[civiceg]

 

 

I'm curious as to why you would need to run switches inside the machine. If the fixture develops a vacuum leak/loss in the machine a sensor in the line outside the machine would register.

 

I would think you would get the most accurate or fastest reading at the fixture than down the line especially if you have a large cfm pump. 

[Josh Kinney -Elite Engineering]

I also have a cfm meter for both pallets. You may have vacuum at the face but your at the limits of what the pump can flow to overcome the leakage....

 

This is the first project where I've done everything from machine purchase to fixture design and built/installed all systems. I'm pretty happy with it

[YoDoug®]

Not true. A 1/4" line can flow 7cfm. Same as my pump. I'm sensing vacuum directly at the part face independent of the vacuum line. Spinning a 6.5" face mill you wanna shut it down asap if you lose vacuum

 

I am confused by your comment. Flow rate does not mean pressure. If the system sees X amount of hg in vacuum as soon as there is a leak it will drop even if flow continues. If there is a port smaller than 1/4 inch downline the 1/4 line may show some pressure diff but it would not equal the total vacuum if the system was enclosed. I have worked on a horizontal with vacuum fixturing and a pressure switch outside the machine. It was able to immediately Estop the machine if there was a pressure loss. The key is using an electronic pressure switch that allows for the right range adjust-ability.

[Josh Kinney -Elite Engineering]

OK. Let's say your line flows 4cfm. That line feeds four faces. One face is leaking 1cfm and let's say that draws that vacuum down to 15inH on that one face. Your gauge will still read full vacuum because it can flow more then the leakage and therefore maintain the vacuum. Not at that one face that just hucked a part though...

 

I've seen this happen all the time on our old design.

[Josh Kinney -Elite Engineering]

I think the key here is the rotary union has a smaller office and therefore creates a restriction.

[T_MALENA]

^{Hard to tell from the pics.  If your CNC has two pallets that the machine rotates into position. I had a similar setup on a Okuma MA500.  So use 3 unions. One main union at the center rotating "bulk head" between the pallets. Then another union on the center of rotation of each pallet.}

[T_MALENA]

On to the leakage and cfm flow...

 

Maybe I'm not thinking about this right. But if you are pulling a vacuum don't you want your pump to flow as much CFM as possible to maintain a seal. And once you have a seal you are flowing 0 cfm & inturn you are pulling 29" of mercury.   So if you have a leak the cfm flow will hold the part back down & reseal the gap. Then with a in line switch monitor the vacuum & alarm if it drops to say 25"...or whatever allows your part to come of plus a little.

 

That is the setup I ran with for a few years on a Horiz CNC & adapted and refined it to a couple other CNC's here.

[T_MALENA]

On a side note "vaculok.com" (where I got our pump, 120 cfm)   NEVER type in "vac-u-lok.com" that's how they spell their company name. don't ask how I know...just don't do it.

[Josh Kinney -Elite Engineering]

It doesn't matter how much cfm you have if 29inHg won't hold the part down then 5,000CFM at 29inHG isn't gonna help. The leak occurred at 29" so more volume at 29" means nothing.

 

My point is if the line before flows 4cfm but you have a restriction down to say 1cfm in the rotary union them the part could be gone and the line would still read full vacuum up stream. I've seen this happen over and over and hence the reason for a separate isolated port on the face of the fixture for monitoring vacuum. This line goes to the switch and vac gauge. The cfm Meter is in the line before the pallet and tells me the total leak down.