Making a Die?

[Tenson]

Hi Chaps,

It's been a while since I posted here, my CNC mill has been working great!

I'm wondering if someone has advice to lend about how to make a 'die' for cutting 1.4mm 'mountboard'? I need to produce the part below. Mountboard is a paper-pulp board usually for mounting pictures for display. I imagine it can be cut in much the same way as cardboard which is with a 'press' and a cutting die. Can one buy sharp edged metal strip to be formed into the desired die?


http://www.mycncuk.com/attachment.php?attachmentid=15840&stc=1

Cutting Die example:
http://www.mycncuk.com/attachment.php?attachmentid=15841&stc=1
http://www.mycncuk.com/attachment.php?attachmentid=15842&stc=1

[IanParkin]

Thats a standard cutting form within the print industry
if you are just wanting the one making I would find a cutting form maker and let them make it
I have customers who make their own simple ones with a fret saw and hand bending the cutting blade into the cut
if you want a bit of blade to try to make your own let me know..
How are you going to use the form once you have it?

Ian

[Tenson]

I was thinking of making one myself. I imagine a couple of thick plywood boards, one holding the cutting blade and then pressing them together with the material between. A screw in each corner would allow me to get the required pressure. That's my idea anyway.

I can cut the board with a slot for blade on my mill, but the thinnest bit I have is 3mm. How thick is standard cutting blade?

If my plan sounds sensible I'd love to get some cutting blade from you!

How does one normally form and fix the blade into the press board? Just bend by hand with pliers and fix with epoxy?

Thanks,
Simon

[IanParkin]

The cutting rule is about .5mm thick
creasing rule is thicker
the rule is just pressed into place

dont underestimate the pressure you will need to cut even one sheet of paper with a form like this

presses to do such a thing are very heavy and exert mega pressure
and are precision things

one way of doing it is to place the form on a base board then place the board that you want to cut on top and then run a roller over the board
forms are made to 0.918" high
the roller needs to run at that height over the form
you place bits of foam rubber next to the blade to push the cut edges away from the blade

I think your idea of 2 boards with screws is possible for such a simple form but very slow...how many cuts do you want to make?

[Tenson]

The cutting rule is about .5mm thick
creasing rule is thicker
the rule is just pressed into place

dont underestimate the pressure you will need to cut even one sheet of paper with a form like this

presses to do such a thing are very heavy and exert mega pressure
and are precision things

one way of doing it is to place the form on a base board then place the board that you want to cut on top and then run a roller over the board
forms are made to 0.918" high
the roller needs to run at that height over the form
you place bits of foam rubber next to the blade to push the cut edges away from the blade

I think your idea of 2 boards with screws is possible for such a simple form but very slow...how many cuts do you want to make?

I need to cut about 100 pieces. I was thinking of putting 4 shapes on one press. Perhaps that is too ambitious if you say it needs loads of pressure. Still I can experiment. The roller is a good idea.

How do you usually cut the form with a slot only 0.5mm thick? Do you use a mill? When yo say the blade is pressed into place I guess you mean into a grove pre-cut to shape.

I was thinking of something like this press, which I use for veneering A4 size panels.

http://s17.postimg.org/xr50g4127/press.jpg

[IanParkin]

Commercially they are done with a laser but one off simple ones with a large fret saw
you will never get enough pressure with that press to cut 4 at once in the middle
you may do 1 if the bolts are close to the cutter

[Tenson]

Commercially they are done with a laser but one off simple ones with a large fret saw
you will never get enough pressure with that press to cut 4 at once in the middle
you may do 1 if the bolts are close to the cutter

It's starting to sound like I will get the job done faster by just sticking the sheet on my mill. Thanks for all your information!

[Musht]

Known as a steel rule die or knife.

Knw someone who uses them for leather , with a 17 ton clicker press...

[IanParkin]

I got these from a customer today
a piece of cutting rule
and a card shaped form
if you want them let me know and i'll put them in the post for you to experiment with

Ian

http://i417.photobucket.com/albums/pp251/ianpark1/DSC00593%20Large_zpsifqeinfb.jpg (http://s417.photobucket.com/user/ianpark1/media/DSC00593%20Large_zpsifqeinfb.jpg.html)

[totts]

I work in the thermo forming industry where we machine and also hand bend blades, as above steel rule. Laser cut into wood and the blades slot into the wood. If there is several blades then these are placed askew so the roller that rolls onto never cuts on a straight edge just on a point, to reduce the pressure needed.

You could place the paper on the cutter and then nylon on top and use a mallet and tap arround.

[Tenson]

Thanks for the helpful replies. I'm getting the card laser cut, for the quantity I need and not having a press it is easier.

[AT Laser]

I have plenty of Cutting rule, Perf rule, Crease Rule in different heights and thicknesses, from 2pt (0.71mm) up to 6pt (2.1mm), until Covid killed us econmically, that was our trade, making Cutting Formes for the Print, P.O.S., Packaging, Automotive, Gasket, Leather and all sorts of end users

The heights range from 21.60mm up to 38.10mm

Just to confirm what has been said previously, 15mm ply (in the main) was cut on our laser to the required shape, with, what are called "bridges" (gaps in the channel) where the base of the rule had a "U" cut out of it in the identical position, which was then inserted into the board (we would typically burn 0.70mm at the top surface of the board and approx 0.75mm - 0.80mm at the back in order to eliminate bowing (Saucer shape). I still have a couple of deep throat diemaking saws for sale and the 2pt/3pt saw blades, if anyone wishes to make them the traditional way