Table/spoilboard assembly question - "Super Track" idea

My PRSstandard 4x8 arrives on Monday! After a year+ of dinking around with the Handibot, I am very excited to get moving with a full size machine. And I expect to be a frequent visitor to this forum as I fail my way to success getting this all up and running. ;)

I will be cutting a lot of full size sheet goods, and I won't have a vacuum table. I am obviously looking for maximum versatility and flexibility for hold down methods and, if possible, I would especially like the option to hold down stock without screwing it to the spoilboard.

So two questions:

1. If you were putting together your Shopbot from scratch, how would you do the table/spoilboard set up? Per Shopbot instructions or modified in some way?

2. Does anyone have an opinion about the "Super Track" method that r26D used when they put together their Shopbot? You can see the blog post here: http://www.r26d.com/2015/01/30/keep-...e-super-track/

Potential issues I see:

• less Z travel
  what about 97x49 MDF sheets or oversized stock in general?
  what about variability in plywood dimensions?
  concerns about spindle hitting hold down clamps?

Thank you!
Brian

I will be cutting a lot of full size sheet goods, and I won't have a vacuum table.
A lot of full sized sheets = vac table. Spend the money you will be very happy you did.

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Originally Posted by Kyle Stapleton

I will be cutting a lot of full size sheet goods, and I won't have a vacuum table.
A lot of full sized sheets = vac table. Spend the money you will be very happy you did.

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I hear you...but I am not going to spend the money -- at least not yet. I can't be the only person cutting full sheets without a vacuum table, so I am looking for the next best setup.

I did the same thing you did, go from a Handibot to that exact same machine. Here's how this is going to go:

You'll go without a vacuum table and you'll find all kinds of ways to hold stuff down.. I was using carpet tape, clamps along the edge, and even using the spindle to mark out where I wanted screw holes so I could screw sheets down. That'll get you so far until you realize that you're spending so much time fighting to hold down warped material, cutting and sanding off tabs, and chasing screws (I know you said you won't use them, but you will, trust me.)

Then you'll finally but the bullet and build/buy a vacuum table. I did after a year of fighting with hold downs and I wish I had built my vacuum table from day one. It would have saved me a lot of hassle and frustration. Hassle and frustration=lost time and money.

Now, I'm saying all of this with the assumption that you're cutting a lot of full size sheet goods like I do. And based on that "super track" thing you posted, it looks like you're trying to figure out ways to hold down full sheets. I wouldn't bother spending the money on that track, just get a pile of cheap pump clamps, they'll work just as well and cost a fraction. That'll get you started on day 1 and you'll always use clamps like that for something so it's not money wasted.

There are a lot of people on here doing a lot of different things. If you're jigging up special things, like for instance logs, mouldings, or other hard to vacuum items a lot of users have made T track or other physical hold downs. For people who only do things like that, a vacuum probably isn't for them. If you're going to be doing primarily sheet goods (plywood) a vacuum is the way to go.

I do some smaller work to that requires the use of vices, T tracks, and other physical hold downs that a vacuum can't work on. What I do is build these on sheets of plywood I call "carrier boards". I can drop these jigs anywhere on to my table, flip on the vacuum and I've got an instant setup. As soon as I'm done I can just pull it off and I'm ready for sheet goods again.

Check out my vacuum build guide here: http://www.talkshopbot.com/forum/sho...esign-thoughts . Just ignore Joe. :mad:

Mine's a little more complex, and there are some simpler designs and frankly some better ones than mine. I've got mine fully documented so if you want the files I'm happy to share.

Oh my. Eric thank you for the detailed response and offer to help. I’d definitely appreciate the files.

About how much $ am I looking at for a vacuum system? I realize there’s surely a range, but a ballpark would help. I’d be willing to do some of the work myself.

I’ll get the machine set up and screw stock down for the short term and see what my needs dictate. The first couple of months for me will be all about prototyping anyway, including opendesk stuff, so I’m not under any production gun yet.

I love the carrier board idea by the way...I’d be curious to see what you’ve built for which purposes. I also expect to cut smaller pieces and edge glued panels that are 4’x4’ or smaller.

I do a lot of OpenDesk stuff myself, so we're in the same boat. My system is an 8 zone system that has 4 lighthouse motors: http://www.centralvacuummotor.com/shopbot.htm

These motors are the same kind of motors that you'll find in a whole house vacuum. The way I have my system setup is this:

I've got the 4 motors in a box (that has good ventilation) and each motor is plumbed to a check valve. The check valve is something you'd used in a sewer system to prevent sewer gas. This way I can have any combination of 1-4 motors pulling vacuum. From there, it's plumbed out to 8 zones, each 2' x 2'. If I'm doing a full sheet I open up all the valves and run one or two motors. If I'm running a smaller job, I can cut off zones one at a time using the valves.

Or if I'm cutting something really small I can kick on all 4 motors and direct all of that suction to one zone. It's about as flexible of a system as I could come up with for what I do. Cost? Well, I probably spent a few hundred dollars on piping (those valves can get expensive so look on eBay) and the lighthouse motors are $200 each.

Attachment 30837

Check out this SketchUp model:

https://3dwarehouse.sketchup.com/mod...-Vacuum-System

and more pictures here: https://goo.gl/photos/MUq1RJaKRV2xxrFk7

That model is an exact "as built" model of my system. I went a little crazy with the angles because I thought it looked cool, at the end of the day I think there are only 2-3 different lengths of pipe in there that I precut so it's not as hard as it looks. You could certainly get the same result and have a less insane looking pipe setup if you wanted.

Feel free to ask any other questions here, or you can contact me at www.digitallyfabbed.com/contact

I'd be happy to help.

Here's my setup/ Just regular t track stuff. On the side is t track on a 2x4. The spoil board is just stacked blocks. The bottom block is bolted and the top is glued. Allows to machine down to the first layer and then re-glue a new layer. I replace the top layer about every two or so years. Enjoy your new machine. BTW I still use screws on occasion. Russ

http://www.talkshopbot.com/forum/att...id=30838&stc=1

http://www.talkshopbot.com/forum/att...id=30841&stc=1

http://www.talkshopbot.com/forum/att...id=30839&stc=1

http://www.talkshopbot.com/forum/att...id=30840&stc=1

I started without vacuum. :(

Then I purchased 2 lighthouse motors and built a box :)

I now have 4 motors with 3 hooked up, what a big difference!! ;)

It only takes hitting one screw with a $75.00 bit to really get your attention.

My suggestion is purchase 2 motors and build a box, you will be glad you did.

Tim

Russ thanks for sharing. I’m intrigued. Does the whole spoil board set up of blocks measure out to 97x49 in total? Are there times you wish you had a vacuum?

Eric, that’s a sweet vacuum set up. If you rig it all 220v, how many amps does it take on your panel? And is it really loud to run the shopbot, dust collector and vacuum all at once?

Each motor is 7 amps, I only run two at the same time usually. I've got it hooked up to a 30 amp breaker. As far as noise, because I have it in a baffled muffler box, it's not that bad. I wear hearing protection, but only because it drones after a while. If you download that SketchUp model you can see how I did a labyrinth patter for the exhaust air to escape. If you've got a router that's going to be your loudest thing in the shop.

Are there times you wish you had a vacuum? I am not a production shop where quick mount / quick release is an issue. I use a lot of 2 sided tape for my smaller parts otherwise it's all clamped. For the tape I put down a layer of masking tape, then the two sided tape then on the back of the substrate I put a layer of more masking tape, then stick down the substrate. Makes for a very quick cleanup. Russ

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Originally Posted by bking1836

About how much $ am I looking at for a vacuum system? I realize there’s surely a range, but a ballpark would help. I’d be willing to do some of the work myself.

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I spent about $100 to $150 on PVC plumbing to run a 4 zone system on my 4x8 table. They are hooked to 2 FEIN Turbo 3 Vacs. Don't think you can get the Turbo 3 anymore, but the Turbo II you can get for $350. I've heard some people say the run off 1 Fein II for a full size table, not sure about this, maybe someone with more knowledge can chime in.

With that setup running, I cannot budge a full size sheet when on my table.