Cutting dies -- accuracy and alignment

[Matt S]

I'm seeking the advice of members who have experience of using strip knives/clicker dies for manufacturing small strap goods in the high dozens or low hundreds.

I manufacture dog collars in a few standard sizes from two layers of waxed 2mm chrome-tan. At the moment my procedure is:

1. Cut strips to final width using wooden strap cutter
2. Mark all holes and lengths using a story stick and dividers
3. Cut to length with knife and end punch
4. Punch rivet and tongue holes using standard hole punches
5. Skive turnback
6. Glue
7. Add buckle and rivet in place
8. Machine stitch all round
9. Add D-ring and rivet in place
10. Punch buckle holes

(The leather I use is through-dyed and the fibres quite tight so I don't edge finish in any way. Both I and my customers are happy with that.)

With sales speeding up and trade enquiries coming in I'm looking at getting cutting dies made. The objectives are to reduce production time and eliminate errors caused by mismeasuring and operator error (strap cutter!). A further objective is to test the feasibility of this approach with a view to offering other products that cannot be made using a strap cutter and would be uneconomically slow to cut by hand.

I've specced about a dozen dies before and been happy with all of them however I've never specced any that need very tight alignment between two different dies. My dilemma is this: can I reasonably expect the backer/lining die to cut a piece that matches perfectly with the top piece? This is in reference to outline and adjustment holes. If not I could spec the lining to be cut a little wider and longer than the top piece and trim the lining by hand once stitched together. Similarly, I could spec the die with adjustment holes only in the top piece and punch the holes through the lining manually. However both of these approaches still allow for operator error and will take some time, reducing the efficiency savings that using dies might bring.

My main alternative plan is to spec some dies without cutting edges just punches in the relevant places. I will mount it into my fly press and use it to punch pre-cut strips held by an alignment jig.

These dies will be long, involve several punch tubes, and I need to order them in several sizes so they represent a significant financial outlay. Any relevant advice will be greatly appreciated!

[Ferg]

I have made several styles of Leather Cell Phone covers. I made my own dies, yours would be more complicated and needs to be done by someone who does them all the time

and with the pertinent machinery. That said: I glue the back/inside and front pieces of leather together a little larger than the die. I have them cut precisely the same.

Your main die would cut the perimeter.

The die made with a blunted edge for the perimeter with the punch tubes mounted. The blunt edges on the perimeter would keep the die from moving.

Just as you have said above.

Ferg

[plinkercases]

Ferg any pictures of your home made dies?

[Ferg]

[plinkercases]

Thanks Ferg

What gauge and hardness strapping did you use and did you form them then put the edge on them? This is exactly what I was thinking about for some simple but repetitive shapes I need to make.

did you use a carving tool,  router or Dremmel to make the groove in the wood backer?