Need some help with some pneumatics

[singlecoil]

I want to construct a single purpose woodworking machine.

This is the sequence of operations I need it to carry out-

Clamp the material
Plunge a cutter into the material
Withdraw the cutter
Plunge a different cutter in
Withdraw that cutter
Unclamp the material

I'm thinking that suitably sized pneumatic cylinders would be ideal for this task, but I know nothing about the practicality of constructing such a system, especially the sequencing, and would greatly appreciate some knowledgeable help.

[FRJ79]

Most people use vacuum holding on CNC applications, I can help with the vacuum pump but not sequencing - this would be controlled by the CNC machine

[oddball1313]

How big is the part? - I’ve got a warehouse full of used CNC machining centres for sale

[singlecoil]

Thanks. This isn't going on a CNC machine, it's for a standalone machine that will drill two holes while the material is clamped, and it needs to be a sequence so that the bits don't hit each other.

[singlecoil]

oddball1313 said:

How big is the part? - I’ve got a warehouse full of used CNC machining centres for sale

That sounds interesting. The largest part would be maybe 2000mm x 600mm (kitchen cabinet part) but one of the holes needs to be drilled in the edge, and it strikes me that a CNC router big enough to do that would be a) far too big for my workshop and b) somewhat outside the budget for this machine (c.£2K).

[CubanPete]

SMC do a branded plc (programmable logic controller) that you can use to sense / sequence drive the pneumatics. I believe it is a rebranded mitsubishi PLC.

Plenty of ways to control them easily.

Sounds reasonably straightforward. The suppliers will probably do most of the system design work for you as part of the sale.

SMC
Norgren
Festo

Are the big names.

[CubanPete]

Could you get a stepped cutter ground for you so you can do it in a single operation?

[singlecoil]

CubanPete said:

Could you get a stepped cutter ground for you so you can do it in a single operation?

There is a machine that uses such a system, I already have one, but the results leave something to be desired, mainly because it operates a drill speeds. maybe 3,000 rpm and I need something that operates at router speeds 16,000 rpm and up, and where the cutters enter the material at different angles and from different directions.

The PLC you refer to I think would be ideal for an industrial application but perhaps a bit OTT for my projected use.

[CubanPete]

A small PLC is only be 16 I/O, which you will use quickly once you have sensors for the end stops, tool shuttle position and a safety circuit ... A small plc is only a bit over a hundred pounds

It almost certainly should be (self) certified as CE compliant, not difficult, but a volume of work.

Can't you use a stepped tool with a high speed spindle? Or used CNC as suggested.

[singlecoil]

CubanPete said:

A small PLC is only be 16 I/O, which you will use quickly once you have sensors for the end stops, tool shuttle position and a safety circuit ... A small plc is only a bit over a hundred pounds

It almost certainly should be (self) certified as CE compliant, not difficult, but a volume of work.

I'll look into it, but I already have a vast amount of brain/office work to do, and the thought of having to learn a bunch of new stuff, while normally ok, really isn't ok at the moment.

CubanPete said:

Can't you use a stepped tool with a high speed spindle? Or used CNC as suggested.

Basically no, to be worth it the cuts have to come at different angles and from different directions, one into the face of the material and one into the edge.

I (and quite few others) have tried to make the CNC thing work in this application, but it calls for a 5 axis machine. I already have a 3 axis CNC router, and there's no way it could do this job. Plus a new toolpath would be needed for each cabinet part. If I can make the machine I want to make I'd have the job done in the time it took to set up the CNC.

[Vincecj]

I could be talking utter rubbish here, but could you use two routers in drill stands and slide the work piece along a fence?

[singlecoil]

Vincecj said:

I could be talking utter rubbish here, but could you use two routers in drill stands and slide the work piece along a fence?

It's not rubbish at all, but the idea is to integrate all the functions in such a way as to speed the whole process up. Your way could be made to do it, but not to do it quickly. One of the problems of using two different locations, even if they were linked in some way, is to ensure that the second hole is made dead in line with the first.

[spikeyhead]

You could modify a capstan lathe, but it would be a lot of work to do it.

[singlecoil]

I think it's really nice the way people are trying to help me with the problem by finding alternatives, but if I could deal with the pneumatics side of it then I've got the rest of the problem covered simply and cost effectively. Time for some more research I think.

I found at today that the US made machine that is designed and made to do this job costs the best part of £6K in this country, it's listed at $3,790 on the US web site. I haven't tried to import one directly because they have a UK distributor, and none of their US agents do export. I don't think I would be keen at that price even, especially after the freight and import taxes.

[matjk]

PLC and pneumatics is not to complicated , a PLC I really like is by a company called Velocio , it’s supper easy to program with a flow diagram , so it’s graphical .
Can you link to the machine , I’m intrigued to see what it is your making ?

[singlecoil]

I did look into the PLC thing, it seemed I needed suitable software on a laptop to program it, plus I would need the various interfaces between the PLC and the stuff it was controlling. The opportunities for getting it were mounting up which leave me looking for a simpler solution even if it is not so sophisticated.

I want to duplicate the action of this type of machine. It's a pocket hole machine, it provides a way for wood to be joined with screws where they won't be visible in use. Not really suitable for melamine/chipboard but ideal for me as I use birch plywood for my cabinets.

Castle USA are the only people who make this type of machine.

https://castleusa.com/products/a00024-tsm-22-pocke...

As you can see it's priced at $3,790, here's the same machine on a UK website at £5,898 incl VAT

https://www.mwmachinery.co.uk/tsm-22-pocket-cutter

[matjk]

Wow , what a concise reply ! Short and with all the information.
This mechanism looks nice and it simplifies the amount of control you would need as the router but can’t hit the drill
https://youtu.be/UvECdR-TH4A

[matjk]

I know a router will cut faster but a semi manual machine looks pretty dam quick to me , are you creating a stacks of pockets on a day
https://www.dm-tools.co.uk/mobile/product.php?site...

[singlecoil]

matjk said:

Wow , what a concise reply ! Short and with all the information.
This mechanism looks nice and it simplifies the amount of control you would need as the router but can’t hit the drill
https://youtu.be/UvECdR-TH4A

That's very interesting, thanks. I had wondered about some kind of circular/reciprocating motion and there it is. Not on the Wurth website any more so my best guess is that it is/was made in Italy and they thought about selling it in the US. They do have the aforementioned Castle machines on their website though.

[singlecoil]

matjk said:

I know a router will cut faster but a semi manual machine looks pretty dam quick to me , are you creating a stacks of pockets on a day
https://www.dm-tools.co.uk/mobile/product.php?site...

I already have one! It's not about the speed (although speed is always good to have when one does stuff for a living). It's about the quality of the edges of the hole (Kreg machine leaves quite a rough edge) and the angle that the screws will enter the piece that it is being fixed to (Kreg is 15 degrees, Castle is 6). Also, the Kreg machine means only one hand on the material, much much better to have foot operation.