what size motors for cutting photo mount board

[mmcp42]

I was at a photo trade show today (one of my other money-pits is photography)
one of the stands was showing a CNC photo mount cutter (now that's a neat idea I thought)
popped in to take a look

now the table size was about 4 feet square
remember this is cutting photo mounts out of 1/8" thick cardboard

the X and Y axes were belt driven, but the steppers were humungous
must have been 4" square and 8" long
now I now it had a fair rapids speed (6 feet per second I think the nice lady said) but are motors that big slight over kill or what?!?

whileI was watching it was fast, but I would doubt 6 feet per second, maybe 2 at best

[klonx]

They were Nema 34 sized motors probably something in the range of 4-8 newton

I was probably at the same show as you and came away with the same idea as you as I hate cutting mounts. I've pretty much designed my machine with the exception of the mechanism that is required to drive the blade in at an angle, need to give that some more thought

[mmcp42]

the other thing I noticed is that they were cutting the back of the mount
I would have thought that made getting the corner bevels right very difficult?

I wondered about using a stepper to rotate the knife blade, that way you could set any arbitrary angle
Software would have to make sure the angle was the sam as the direction of travel

Also have to take into account bevel, so there's a compound angle going on
hence my query about the corners

where you based btw?
I'm in Leighton Buzzard

are you aware of the Talk Photography froum, I loiter there sometimes as well

[klonx]

They cut from the back as it avoids marking or damaging the face of the mount either by the cutting head or the clamps that hold the card flat.

My manual mount cutter works in the same way and it is pretty accurate and easy, any slight overcuts are not noticable but this can be very finely tuned in cnc, the angle of the blade never changes during a cut so it can be in a fixed holder. I'm planning to have utilise different holders for different blade angles, 45 and 90 degrees initially for angles and staright cuts, ie trimming edges. The cutting head will need to leave the card and reinsert at 90 degrees for the corners.

I'm based near Cambridge, I post on talk photography too under the username 'Hairyduck', thought I recognised your username from somewhere

I've also had a brain wave about the cutting head and recon I'm ready to start building a concept for that, as soon as I can make any space in the garage

[mmcp42]

when you're ready - I'd love to see the brain wave!