Anyone own a scroll saw?

[Julian]

If anyone has a scroll saw, would they mind trying to cut a piece of foam rubber about 1" thick before I go out and buy one?

Surprisingly a band saw will cut foam beautifully in straight lines, but it's not so good at cutting round tight corners.

[Jamesrl]

If anyone has a scroll saw, would they mind trying to cut a piece of foam rubber about 1" thick before I go out and buy one?

Surprisingly a band saw will cut foam beautifully in straight lines, but it's not so good at cutting round tight corners.

I use one of them there electric carving knives with the two reciprocating blades for cutting foam upto 6" thick.

[Julian]

Great info there ,,, thanks!

So any one own a scroll saw?

[Jamesrl]

What about a hot wire?

[Julian]

I did think of that but ... temperature control, I think, would be quite critical so as not to produce burnt edges and, unlike polystyrene foam it evolves toxic fumes.

I suspect just a wire on the band saw would work which would be good as I'd be cutting the foam with a template on top as a guide, but how to join the wire.

Been using printed templates, but the band saw blade files away the edges, hence the thought of a very fine scroll saw blade with no set in the teeth.  Or perhaps a wire on the scroll saw ... very thin wire rope may be better as the twists may assist cutting and it would work fine against a steel template.

I tried making a wire loop from stripped copper flex by soldering the two ends pushed into each other and carefully grinding off the excess.  The solder spread too far down the strands making a stiff section and many strands broke and tangled.

Been thinking about die cutting but buying small quantities of knife rules seems difficult.  If I go down that route, whats the thinnest router bit you have and how deep will it cut.  Your router would be perfect for making the die blanks. Failing that it would be back to the scroll saw to cut the blank.

[Dickjotec]

How narrow is your band saw blade? I use 1/4 inch blades which work fine but I have not done tight radius, how tight is the curve you are trying too cut?

[Jamesrl]

Been thinking about die cutting but buying small quantities of knife rules seems difficult.  If I go down that route, whats the thinnest router bit you have and how deep will it cut.  Your router would be perfect for making the die blanks. Failing that it would be back to the scroll saw to cut the blank.

I have a 1mm diam 10mm deep cutters but will look to see how small they go.

[Jamesrl]

Cutters are available down to 0.1mm with possibility a 10mm cut depth.

Routing a base board with a 0.1mm cutter would have to be done veeeeeeeeeeeeeeeerrrrrrry slowly, I'm up for it if you'd like to try it.

[Julian]

How narrow is your band saw blade? I use 1/4 inch blades which work fine but I have not done tight radius, how tight is the curve you are trying too cut?

It's a ½" blade and the corner radius is 10mm.

I appreciate a narrower blade may be better, but the foam moves quite a lot as the blade turns, plus there's still the problem of damaging the template.

Oooo, just had a thought as I was typing I could try drawing round the template and doing my best to follow the line accurately as well as rough trimming and cutting radially close to the corners so the waste has less effect ... might give that a go.

[Julian]

Cutters are available down to 0.1mm with possibility a 10mm cut depth.

Routing a base board with a 0.1mm cutter would have to be done veeeeeeeeeeeeeeeerrrrrrry slowly, I'm up for it if you'd like to try it.

Knife rule die making is quite a fine art.  When I ran the sign company we had a Crossland platten it's the most scary machine I've seen.  The coordination needed to run it is mind blowing.  Look here ... https://www.youtube.com/watch?v=CKflFi_LVe0  This guy is a real woos.  The machine is set on dwell.  Our operator had the machine running continuously, taking out with one hand and loading with the other.  He could set it up to cut tissue paper without the blades touching the anvil ... deep respect for that guy, a real craftsman.

We used to cut quite complicated shapes from 1mm rigid PVC sheet the noise as it cut was remarkably loud and near the machine you could feel the concrete floor vibrate!

The die making was subbed out ... wish I'd paid more attention to who we used and how they were made. These are a couple of videos of die making ...

https://www.youtube.com/watch?v=ktNmcrFPWgY

https://www.youtube.com/watch?v=HKJoyh49vdI

I need to find out a bit more about the knife rules.  The only thickness dimensions I've seen quoted are 2 pt and 3pt obviously there's black magic involved in die making.  My guess would be that they are about 0.5mm.

Then they need notching to suit the bridges in the die board, but I guess that could be done on a grinder.

I'll bear the offer in mind, Jim, but the scroll / band saw route at the moment seems to be the simplest.

[Jamesrl]

I've made some basic dyes before and used a fly press to apply the cutting force.

I've seen those stamping machine in action in a cardboard making factory we were working in, it was running at approx a stamp every 2 secs continuously, I thought at the time"get the timing wrong and you're minus one hand", the operator was a lad with downs syndrome but feck he was good at it.

[Julian]

Sitrep ...

I might do away with rounded corners and simply chamfer them.  It seems to work just as well in this application and can be done on the band saw.  Once I've worked out why the nozzle and heater block ripped off the printer the last time I used it, I'll print a 45° jig to get them all the same.

Holes in foam are a breeze ... remember the cutter I made for the condenser tubeplate I posted on the VOD?  The same principal of sharpening the inside edge of a tube and running it slowly on a drill cuts perfect holes in foam.