Looking for Help cutting composite material

**Robin Hewitt** · 02-11-2009

Wood? That rather precludes adding a backing sheet so you can use use a vinyl cutter with ink jet. You are now have a flat bed table with either 3 heads or interchangeable. The set width and heads requirement sounds like a bespoke machine.

I think you need an engineer. If I was still young and hungry I'd draw up the table as a kit of parts for laser cutting (needs tube and sheet cutting lasers), estimate the price, double it so I could remake the whole she-bang when I understood the problem and relieve you of the money

Some thoughts.

If you want to do wood you will need dust extraction.

Make sure it will do the max length you may ever require in the future. Be generous.

When you cut this sheet with a knife, could you do it one handed or would it slide about everywhere? If it slides you will need a vacuum or electrostatic hold down.

Pen plotting text is dismally slow (especially if you add the inertia of a router head) and you will probably want a soft landing for the pen.

Are you really sure this is the way to go? Beware enthusiam :naughty:

Good luck

Robin

**irving2008** · 02-11-2009

As an engineer, albeit one with little money and even less time these days, I'd say this was a do-able one-off. Yes it has its complexities, but no more than some of the others we've seen (I recall the one that someone designed to cut large blocks of foam for car body prototyping).

A 2.5m x 1.2m (8' x 4') bed isn't impossible, we've seen bigger ones. It doesn't sound like excessive rigidity would be critical here if MDF and foam/composite is all thats being cut. I'd like to see some trials of cutting the composite with a 3 or 4mm single flute cutter in a high-speed spindle to determine whether that would work (maybe WebDude could send someone with a suitable router setup a sample of the material to see how it cuts - offers anyone). I do have some concerns about workpiece holding and also what the sacrificial layer underneath would be as a through cut is needed. It may be that a laser would be a better solution for this material but again some trials would be needed to confirm this (wasn't it Mike at TechServe that had a big-bed laser cutter or did I imagine reading that? If so, maybe he could offer to trial cut a sample to see how effective it is)

Some ingenuity around the spindle/head is needed. I'm sure a dual-head arrangement with a pen and a cutter could be designed and speed wouldn't be too big an issue if there was relatively little text (again some calculations on total stroke length of the writing and moves needed would give some idea of the time taken). A more sophisticated solution could be based on a hacked ink-jet printer.

An interesting challenge and one I'd love to have a go at. I'd have thought it was do-able for less than $25k if 80-90% 'home' built.

**webdude12** · 02-11-2009

I am not trying to cut the wood and the foil material at the same time nor even within the same day. We just have some other products that we make that if we are going to have to use a CNC to cut the foil material, we can make the other products on it as well.

Have no problem manually changing the heads out, based upon what we are cutting that day.

It will need to cut upto 1/2" MDF, 1/4" and 1/8" ABS plastic, and then the foil material.

As far as dust collection system, we already have that in place on our table saw and router table.

I would be more then happy to send someone a sample piece of the foil material. The material we are using is ProDex Insulation. It is fairly ridged, but still has a flexible property to it. More info on it can be found here:

http://www.insulation4less.com/Insul...nsulation.aspx

The Pen / Sharpie is not critical, just trying to keep the guys from having to hand label that parts after being cut. But push come to shove we can still do that if need be.

**Robin Hewitt** · 02-11-2009

If you have dust extraction that would do nicely for a vacuum hold down.

Not sure if 1/4" ABS will cut very happily at router speeds, it tends to melt, but I think you will probably want router speeds for the other materials :nope:

If you whack a pen down with a solenoid it tends to dent the surface and deposit a blob of ink. The ink carries on down after the pen has stopped.
If you use a soft landing it takes more time. One speed solution is to use joined up writing

I used to be a service engineer working with Houston Instrument vinyl cutters, pen plotters etc. Gives you a rather jaded view if you only get to see them when they go wrong :whistling:

**HiltonSteve** · 02-11-2009

I would be happy to test cut some material for you on my machine.

I have a maximum feedrate of 5m/min, a kress high speed spindle that runs between 10,000 - 30,000 rpm and a decent size bed 1000mm x 600mm. I have some 3mm cutters but they are 3 flute carbides which are not ideal, if someone has any single flute cutters or can find some at the price then I would be willing to buy some as they will come in useful for other jobs.

Let me know.

**webdude12** · 03-11-2009

What size sample would work well for you? I do not work at the shop location daily, so I would need to go by and cut you off a piece from the roll.

As I said before, the edge does not have to be precision cut, but I would like it to look nice, as what we have been sending customers is razor knife cut.

**HiltonSteve** · 03-11-2009

Any size will do, just cut a few smaller pieces to a size that wont cost a fortune to post.

Where abouts in the country are you?

**webdude12** · 03-11-2009

Actually I am in the US, but this board has been much more helpful then any of those I have found over here.

I can still ship something to you. Would a 60 cm square piece work? or would you like something bigger? I really wouldnt need the sample returned, just if you could take a picture of the edge and post it, that would be great.

**HiltonSteve** · 03-11-2009

60cm square will be plenty. Do you have any example profiles that I could cut with typical corners etc? If so then send me the drawings.

I will pm you my address.

Do you have any preference on the cutters that you want me to try cutting it with? Like I said before I have some 3mm carbides with 3 flutes but I am finding that you have to run these at very fast feedrates to get anything like the correct chip load. I am sure 1 or 2 flutes would be much better.