Belt cutting machines always slightly narrower than "belt width"?

[nstarleather]

Hey everyone...this is something that comes up from time to time with customers that my 1.5" and 1.25" belts area actually narrower than those measurements.  When I set up the stripper to cut the width that's just how they come out. My dad has always said it's because it's meant to work with buckles so they don't rub.

Is this kind of a standard thing or is my machine weird?  You can see my machine is se up with 1" and two .25" spacers.

[AlZilla]

I bet you get a definitive answer. Meanwhile, it does make sense. When I make my belt 1.75" for my jeans that have 1.75" belt loops, they're a very tight fit. 

I imagine Bruce Johnson or somebody will be along with the entire history of it ... 😎

[kgg]

47 minutes ago, nstarleather said:

You can see my machine is se up with 1" and two .25" spacers.

Have to checked with a caliper the spacers to see if they are actually flat, with no wear, the spacers measure out to 1" long and the two smaller ones are .25" and when combine give you 1.5"? A quick check would be to use a piece of 1 1/2" Al edge trim from you local hardware store and see if it will properly between the blades.

kgg

[nstarleather]

12 minutes ago, kgg said:

Have to checked with a caliper the spacers to see if they are actually flat, with no wear, the spacers measure out to 1" long and the two smaller ones are .25" and when combine give you 1.5"? A quick check would be to use a piece of 1 1/2" Al edge trim from you local hardware store and see if it will properly between the blades.

kgg

No I haven't but they're all the same, which wouldn't be the case with wear.  I've got dozens of different spacers: 1/8",1/4", 1/2", 1", 1.5" etc...all come out to slightly narrower I can't imagine it's not on purpose.

 

[Matt S]

My strip cutting machine is only a cheap benchtop one from China, but I have to account for the thickness of the blades when adding spacers. I think the logic goes that the strip is actually the distance between the edges of the blades, i.e. the length of the spacers plus one blade thickness (2*0.5*thickness).

Could it be that your machine originally was designed for thicker blades, which have been subsequently replaced with thinner ones?

[Northmount]

Tandy's belt strips are slightly narrower than the stated numbers too.  There has been a discussion somewhere here before.  As mentioned, it has to do with buckles and belt loops.  Someone can do a search to see those comments/posts.

[nstarleather]

23 minutes ago, Matt S said:

My strip cutting machine is only a cheap benchtop one from China, but I have to account for the thickness of the blades when adding spacers. I think the logic goes that the strip is actually the distance between the edges of the blades, i.e. the length of the spacers plus one blade thickness (2*0.5*thickness).

Could it be that your machine originally was designed for thicker blades, which have been subsequently replaced with thinner ones?

I've got like 3 sets of blades all the same...unless some ancient ones were different...machine is super old.

23 minutes ago, Northmount said:

Tandy's belt strips are slightly narrower than the stated numbers too.  There has been a discussion somewhere here before.  As mentioned, it has to do with buckles and belt loops.  Someone can do a search to see those comments/posts.

Yeah I compared some other blanks and it seems legit but I wanted to find some confirmation...strangely haven't seen the discussion before.

 

[BlackDragon]

My guess is when the leather is being cut it's being squeezed first, which makes it expand. After the blades cut the leather relaxes and goes back to it's normal state which makes it narrower. It looks like you're losing 3/32". I'm surprised people are mentioning it.

You can just tell people it's like buying a Quarter Pounder. The meat is weighed before cooking. 

[nstarleather]

47 minutes ago, BlackDragon said:

My guess is when the leather is being cut it's being squeezed first, which makes it expand. After the blades cut the leather relaxes and goes back to it's normal state which makes it narrower. It looks like you're losing 3/32". I'm surprised people are mentioning it.

You can just tell people it's like buying a Quarter Pounder. The meat is weighed before cooking. 

It's not often but more often than you'd think...
 

[Hildebrand]

@nstarleather I think those that mention a minor discrepancy like that would quickly go on the I am to busy to make your item list.  Hand made items will vary in dimensions, they need to relax a little.

Todd

Edited March 13 by Hildebrand
spelling

[Cumberland Highpower]

You can get spacers made in just about every configuration.  +/-.  

I have a handful of Randall 132's. Older machines, but work just fine.  They had spacers in exact lengths, undersize, oversize, etc.  I tend to use single spacers that are 1/16" under that way the straps come out exact as 1" 1-1/4" 1-1/2" etc.   

Some spacers are also meant to cut straps oversized to compensate for what's lost from an edging machine.  

Spacers are also intended to be stacked.  For example, you can use a 1/4" spacer with a 1-3/16 spacer to get your 1-1/2" strap. (The missing 1/16" is the width of the cutting blade).   When you're calculating what spacers to use, you take the desired strap width and subtract 1/16" to get your total stack.

What's the make on your strap cutter? Looks metric to me.  Could also be your spacers are metric 28mm, etc?  

It also looks to me you're stacking spacers (At least 2 of them) that are each 1/16" under and you're stacking tolerances as a result.  The 1/16" under on each spacer is the width of a blade.  You can correct for that by either using just a single spacer that is 1/16" under actual width of your straps, or you can ADD a thin spacer to your spacer stack that's like  1/16" or 1/8" or whatever you need to make up for the loss if that's all you have to work with.  

You can as a last resort have a machine shop make you some up or cut some down.  I had a relative cut some down for me on a surface grinder.

Hope that makes sense?

Edited March 14 by Cumberland Highpower

[TomE]

I see the discrepancies when repairing tack made in Asia, which is the majority of manufactured tack.  The hardware matches inches but the straps are narrower making them loose on the hardware and promoting wear.  For economical repairs (matching the client's expectations for inexpensive tack) I have to fudge the width when splicing a new end on a strap.  I always check the setting on my plough gauge with a scrap of leather to ensure I'm getting accurate widths.  I realize this is a bit off topic.

[nstarleather]

12 hours ago, Cumberland Highpower said:

You can get spacers made in just about every configuration.  +/-.  

I have a handful of Randall 132's. Older machines, but work just fine.  They had spacers in exact lengths, undersize, oversize, etc.  I tend to use single spacers that are 1/16" under that way the straps come out exact as 1" 1-1/4" 1-1/2" etc.   

Some spacers are also meant to cut straps oversized to compensate for what's lost from an edging machine.  

Spacers are also intended to be stacked.  For example, you can use a 1/4" spacer with a 1-3/16 spacer to get your 1-1/2" strap. (The missing 1/16" is the width of the cutting blade).   When you're calculating what spacers to use, you take the desired strap width and subtract 1/16" to get your total stack.

What's the make on your strap cutter? Looks metric to me.  Could also be your spacers are metric 28mm, etc?  

It also looks to me you're stacking spacers (At least 2 of them) that are each 1/16" under and you're stacking tolerances as a result.  The 1/16" under on each spacer is the width of a blade.  You can correct for that by either using just a single spacer that is 1/16" under actual width of your straps, or you can ADD a thin spacer to your spacer stack that's like  1/16" or 1/8" or whatever you need to make up for the loss if that's all you have to work with.  

You can as a last resort have a machine shop make you some up or cut some down.  I had a relative cut some down for me on a surface grinder.

Hope that makes sense?

So the machine is ancient… like older than me. I’m 43…

Which is why I guess the machine is probably Italian or American because that’s what was around back then.  I doubt it’s metric just because of the spacers I have seemed to correspond to inches and fractions of inches.

 

What you say about the tolerance is adding up makes sense, I think I’m going to see if I have a 1.5” spacer, and if it lines up with one 1 inch spacer and two 1/4”

we sold a lot of belts last year, so I’m not terribly worried. I was just curious, as if it was normal or not… apparently there’s a lot of variation in machines.

[Cumberland Highpower]

33 minutes ago, nstarleather said:

So the machine is ancient… like older than me. I’m 43…

 

That just means you have a good machine! If it's been here for 40+ years it will probably be around another 40?

I'd rather have a 40 year old Italian or US made machine than a "new" Chinese machine anyway!  We have exactly ONE machine here made in China, a hot foil embosser.   Every time I look at it or use it, I feel like tossing it in the scrap pile...Poor casting, machining, assembly, etc.  No heat treated parts, etc.  I bought it at an auction so I wasn't into it for much....

Edited March 14 by Cumberland Highpower