Making a door assembly table

[Bobby Robbinett]

So I bought a huge door assembly table from a guy in Tennessee that did not come with any clamps. The table looks to be rather primitive, not as pretty as a Ritter but much better built. The entire thing is made out of 3/4” solid plate steel with the normal hole spacing you see on other tables. It is 4ft wide x 10ft long and has adjustable squaring bars at the bottom and left side.

Now I am trying to get some clamps going for it to build cabinet doors. I know that I can buy straight from Ritter but they get $450+ per clamp without factoring in a valve, manifold or foot pedal. That stuff if bought from them would add up to several thousand doors.

I need some suggestions on cylinder clamps, and possibly a valve and manifold. I don’t necessarily need a foot pedal as a manual valve would be fine to activate the clamps. I want the clamps to have a 6” stroke and I am guessing a 3/4” bore would be optimal? I like the idea of a spring return rather than having air fed to both ends of the clamps in order to simplify the setup as I am very green when it comes to pneumatics. I can have a machine shop make some aluminum blocks that could go on the shafts of the cylinder clamps. I just need to make sure that my clamps have a threaded end or some way to attach the aluminum blocks to the shafts of the clamps. Not sure how I can make the brackets for the clamps to mount into the holes on the tables. Any ideas on that situation or project as a whole would be great.

So to recap.
I need suggestions on 3/4” bore cylinder clamps with a 6” stroke and spring return.

Need to find a valve or way to activate the clamps.

Need manifold

Need suggestions on how to make the mounting brackets that hold the clamps in the 3/4” dog holes on the table.

Thanks guys!

[Greg Funk]

I think I'd want a lot more than a 3/4" bore. That would barely apply 100lbs of force. I think the clamps Ritter supply are 3".

I would try and make a mount that employs a magnetic handle that locks it to the table. It would require some experimentation but having a single 3/4" post with some type of magnetic lock could work.

[Jared Sankovich]

A 3/4 bore cylinder is only a .44 sq inch area. (44 pounds at 100 psi.) You want 3" cylinders. You could maybe get away with a 2" cylinder but 3 will be a lot better.

[Jerry Bruette]

Just poking around at the Bimba cylinder website and McMaster-Carr for 3" cylinders w/6" stroke and spring return and those cylinders from Ritter are starting to look pretty affordable.

You have to factor in the Ritter product already has some type of mounting/pushing plate system that you would have to make yourself or pay to have made by a fab shop.

A manifold is pretty cheap and I think a foot valve is all you would need for a valve.

Air supply to foot valve, foot valve to cylinders.

Be careful with the foot valve though, I've seen severed fingers because of foot valves that were stepped on at the wrong time. The company I used to work for actually removed every foot valve from the company and replaced them with anti-tie down hand valves.

[Bobby Robbinett]

Just poking around at the Bimba cylinder website and McMaster-Carr for 3" cylinders w/6" stroke and spring return and those cylinders from Ritter are starting to look pretty affordable.

You have to factor in the Ritter product already has some type of mounting/pushing plate system that you would have to make yourself or pay to have made by a fab shop.

A manifold is pretty cheap and I think a foot valve is all you would need for a valve.

Air supply to foot valve, foot valve to cylinders.

Be careful with the foot valve though, I've seen severed fingers because of foot valves that were stepped on at the wrong time. The company I used to work for actually removed every foot valve from the company and replaced them with anti-tie down hand valves.


Would it not be; air supply to foot valve, foot valve to manifold, manifold to cylinders?

What specs should I be looking for in a manifold and what specs should I be looking for in a valve? I would like to have either 4 independent cylinders or have two pairs of two that activate together as one, for each of the two pairs.

I am not sure if it would be beneficial to have them activated as two pairs or individually.

[Bobby Robbinett]

A 3/4 bore cylinder is only a .44 sq inch area. (44 pounds at 100 psi.) You want 3" cylinders. You could maybe get away with a 2" cylinder but 3 will be a lot better.

You are correct. I was thinking the bore was the diameter of the shaft coming out of the cylinder. I would go with at least 3” cylinders or more,

[Jared Sankovich]

Would it not be; air supply to foot valve, foot valve to manifold, manifold to cylinders?

What specs should I be looking for in a manifold and what specs should I be looking for in a valve? I would like to have either 4 independent cylinders or have two pairs of two that activate together as one, for each of the two pairs.

I am not sure if it would be beneficial to have them activated as two pairs or individually.

I'd run a 5 port solenoid and double acting cylinders controlled by a switch footpedal. Or just a momentary switch/switches if you are worried about smashing fingers.
476410

[Jerry Bruette]

Would it not be; air supply to foot valve, foot valve to manifold, manifold to cylinders?

What specs should I be looking for in a manifold and what specs should I be looking for in a valve? I would like to have either 4 independent cylinders or have two pairs of two that activate together as one, for each of the two pairs.

I am not sure if it would be beneficial to have them activated as two pairs or individually.

You're correct I left the manifold out of the circuit.

McMaster-Carr has manifolds made of aluminum part #5469k123 and 5975k12. Each are a 4 port manifold 1/4" NPT
They also have a foot valve in two inlet/outlet sizes part #6654k211 and6654k131. I'd order the safety guard with the foot valve.

You could put individual shut off valves at the manifold for the cylinders and add flow controls to each cylinder controlling the extend and retract speed of the cylinders. Slower extend and faster retract would be my choice YMMV.

With the parts I've listed you would have 4 cylinders that all activate at the same time. If you want all individual activation or groups of two it gets more complicated. With flow controls you could have two cylinders that move slower than the other two, but they will all move at the same time.

[Tom Bender]

It's time for a drawing of the pneumatic circuit. And for those of us with no idea what this machine is, pictures would be nice.

[Jared Sankovich]

And for those of us with no idea what this machine is, pictures would be nice.

10:00 minute mark
https://youtu.be/25GbUnlOHh4

And a diy version
https://youtu.be/gBrIKT59ajk

[Jerry Bruette]

It's time for a drawing of the pneumatic circuit. And for those of us with no idea what this machine is, pictures would be nice.

Here's a crude schematic that doesn't have the "official" pneumatic symbols, but you should get a general idea. The flow controls with the quick exhaust feature allows the cylinder to exhaust without the air going all the way back to the foot valve and should speed up the retraction of the cylinders.

476643

[Bobby Robbinett]

You're correct I left the manifold out of the circuit.

McMaster-Carr has manifolds made of aluminum part #5469k123 and 5975k12. Each are a 4 port manifold 1/4" NPT
They also have a foot valve in two inlet/outlet sizes part #6654k211 and6654k131. I'd order the safety guard with the foot valve.

You could put individual shut off valves at the manifold for the cylinders and add flow controls to each cylinder controlling the extend and retract speed of the cylinders. Slower extend and faster retract would be my choice YMMV.

With the parts I've listed you would have 4 cylinders that all activate at the same time. If you want all individual activation or groups of two it gets more complicated. With flow controls you could have two cylinders that move slower than the other two, but they will all move at the same time.

Thanks for the reply Jerry. I would ideally like to have the 4 pneumatic cylinders operate in groups of two, that way I could activate the two that push the door rails together first, then have the second pair of two activate to push the stiles together last.

I don’t think that I will necessarily need flow control. What ever speed the cylinders end up having is most likely ok. What would I need to make them act in groups of two? I would assume I could just have one manifold and two valves? What would be the best way to make that work?

[Jared Sankovich]

Thanks for the reply Jerry. I would ideally like to have the 4 pneumatic cylinders operate in groups of two, that way I could activate the two that push the door rails together first, then have the second pair of two activate to push the stiles together last.

I don’t think that I will necessarily need flow control. What ever speed the cylinders end up having is most likely ok. What would I need to make them act in groups of two? I would assume I could just have one manifold and two valves? What would be the best way to make that work?

I would certainly put a flow control valve on each bank of cylinders. You want controlled clamping not a wild slap. It's cheap and easy to do476697


As for the isolation of each pair, just add a in line valve or solenoid before the wye to each pair. You can isolate each bank that way.
476696

There really isn't all that much to the pneumatics on these.

[Jerry Bruette]

Thanks for the reply Jerry. I would ideally like to have the 4 pneumatic cylinders operate in groups of two, that way I could activate the two that push the door rails together first, then have the second pair of two activate to push the stiles together last.

I don’t think that I will necessarily need flow control. What ever speed the cylinders end up having is most likely ok. What would I need to make them act in groups of two? I would assume I could just have one manifold and two valves? What would be the best way to make that work?

You could do this in a number of ways, add a second foot valve, add manual valves at the manifold, add manual valves at the cylinder.
With the second foot valve you'd have to change the manifold setup, use two manifolds with two outlets each.
With the valve on the manifold I'd use a brass ball valve with a "Y" going to the cylinders.
Put inline valves like Jared shows.

I would definitely put flow controls in so you have smooth operation and no jumping or slapping.

[Keegan Shields]

This thread is really cool and has so many applications.

Thanks for the info and keep it coming!

[Ronald Blue]

Not an endorsement of any sort and just food for thought. Look at air cylinders on Amazon. As far as valves there are many options. For your application a manual toggle valve would be sufficient. Unless you want automation it isn't necessary. You could have a shuttle valve that wouldn't allow you to apply the one set of clamps before the other set if you desired. Look at push lok air fittings and air line. Fastenal used to carry some of these. If you want to see what you are buying. They make it extremely easy to change plumbing around and experiment. Single action spring return would work unless the clamping assembly is to heavy for the spring return. Posted some links for you to ponder. Several good suggestions here by others as well so lot's to ponder.

https://www.amazon.com/push-lock-air-fittings/s?k=push+lock+air+fittings

https://www.surpluscenter.com/Air-Pneumatics/Air-Cylinders/?page_no=2

https://www.surpluscenter.com/Air-Pneumatics/Air-Cylinders/Double-Acting-Air-Cylinders/2-1-2-X-3-Parker-Double-Acting-Air-Cylinder-4-9058.axd

https://www.surpluscenter.com/Air-Pneumatics/Air-Valves/Manual-Directional-Air-Valves/

[Bobby Robbinett]

I am getting ready to start on this project. Anyone came up with a way to mount the air cylinders in the dog holes on a Ritter style table? I saw a guy on Facebook make a DIY door assembly table setup like a Ritter clone made out of melamine. He built his table like mine with 3/4” dog holes. He made a foot/cradle for each clamp out of wood with HDPE round studs to mount the clamps in any of the 3/4” dog holes and he used a lathe to turn the HDPE to the proper diameter and then secured those to the bottom of the wood cradle that he built for each cylinder clamp.

[Tom Bender]

Ok that pneumatic circuit is a start but it needs more stuff added.

Clamping force - You are going to want a pressure regulator somewhere and maybe more than one. You may want different force on rails and stiles.

Clamp retraction, are these spring return cylinders? if not you will need to switch the pressure to the other end of the cylinders and vent the push side.

Shut off - You definitely want a lockable shutoff valve prior to any other components, preferably a self venting safety valve designed for the purpose.

Flow controls - yes you probably should have one on each port on each cylinder.

Special uses - If you will ever want to close less than all clamps you will want manual valves on those cylinders. Also useful if you want to close in sequence.