Vac hold down addition

[Tim Lucas]

Santa brought me 2 Lighthouse vacuum motors for Christmas!
Built my box following "Black Box Vac" setup for 4 motors but only 2 installed at this time.
Bought some phenolic plywood I was going to use for my plenum :confused: when I started cutting it, I hit cement! :eek: they used it to fill the voids - guess I bought the wrong kind. But anywho I used one sheet under my now mdf plenum, got it cut and set up with 5 zones - bought and installed the Valterra gate valves. Still have to flip the sacrifice board and run across it but the 2 motors held it so tight I could not push it at all :D still need to seal the edges but as it sets now it pulls a vacuum of around 7.8
I used a rubber 3" elbow instead of the straight section and yes it will suck flat :eek: I will change that out to the short straight piece.

Want to thank all those who placed there designs and ideas on this forum as I have learned a lot from them and would not have even known where to start without there post.

Pictures to follow

Thanks again
Tim

[Tim Lucas]

Pictures of upgrade

[Plyoboxwarehouse]

Looks nice! I hope to be doing the same on my new PRS Alpha that I plan to pick up at ShopBot in February! Happy New Year!

[Doug Hawkins]

Just did a 8 zone table with 2 vac motors works great have not got a gage on the ststem yet. With all 8 on and only 4 covered I can not slide the material. I have done some small pieces with something else laid beside and worked fine. Most of the small stuff goes on the desk top.

[gerryv]

Real nice work Tim.

Just noticing your 4th pic. I recall having a PRT like your's several years ago where I posted a pic of my first table flattening, which looked just like yours here. A couple of the experienced fellows were kind enough to contact me offline and fill me in on the benefits and means of "tramming" my spindle/router. Please don't think I'm doing anything other than "paying it forward" as they vastly improved my machine with little effort. :)

[Tim Lucas]

Real nice work Tim.

Just noticing your 4th pic. I recall having a PRT like your's several years ago where I posted a pic of my first table flattening, which looked just like yours here. A couple of the experienced fellows were kind enough to contact me offline and fill me in on the benefits and means of "tramming" my spindle/router. Please don't think I'm doing anything other than "paying it forward" as they vastly improved my machine with little effort. :)

Tramming? Not sure if this is what you mean but I did notice I need to adjust my router a little to the left at the bottom. But please tell me what you see. I can use all the help I can get.
Thanks
Tim

[gerryv]

Hi Tim,
Just wrote you a response then managed to blow it into the great ether somehow and just heading out the door so here's a reference to an old post I participated in on the subject.
http://www.talkshopbot.com/forum/showthread.php?t=17347&highlight=tramming
One of the key's to doing a good job is to make sure you use a very flat plate of equal thickness to tram to. I laid it on my just surfaced and blown off table - nothing sophisticated.

I'm sure that some of the fellows with PRT's can offer other/better pointers.

[scottp55]

Tim, Pretty good thread here too on Vectric,
http://forum.vectric.com/viewtopic.php?f=2&t=21172&p=150038&hilit=trammel#p150038

Money is tight so I used the "stone age" approach with a $2 piece of brass rod bent to give me 9" (Desktop only has 18"Y-bigger is better) when we did the Z-upgrade and Shopbots method of aligning on the spindle was nowhere good enough. MDF was surfaced with 1.25" mortising bit, so you can get fairly good results if you don't have $100+. I know....Brady and others are cringing, but I needed to get cutting again:)
Fred Flintstone:)

[scottp55]

Oh, Just remembered
I started planning to use Starret shim gauges, but then noticed when doing rough alignment at Z "fixed move" of .005" set up that it set up a faintly visible vibration in the brass rod. So I got rough alignment by putting Starret 12" rule down and dropping it down until vibration was damped. Then did same thing with .003" fixed distance, and eventually wound up so that a .001" fixed distance Up move let it vibrate, and a fixed move Down, damped it. BARELY visible vibration at .001" moves---but it was there.
I think shim gauge wouldn't have been as accurate because of the flex in the rod. Seems to have worked well, so thought I'd toss it in. .002" in 9" is good enough for our purposes.

[Tim Lucas]

Thanks Gerald and Scott, good reads. I will work on that this weekend:D