trimmer suitable for perfect bind book

[max.lee]

Hi Guys,

Like some advise from the pros here when come to trimming of perfect binded books.

Currently, we have 2 separate system that does the perfect binding and trimming.

However, our trimmer comes with only 1 knife and whenever we trim a book to its size, the spine of the books will be crumple/wrinkle. This was because we need to add good pressure to the book so that when the knife trim the sides, the book will not move out of alignment.

So i am wondering if my trimmer does not suit perfect binded book as i watch some of the videos online, i found that most perfect bind books are trim with a 3 knife system.

So is there any tips or trick to it?

Thanks in advance for replying!

 

[easiprint]

I think you will find it's the clamp doing the spine crushing, not the blade. What you have to do is stop the spine of the book being held by the clamp. Most three knife trimmers use a wooden block smaller than the books to clamp so the spine is not held. I only have fairly small perfect bound orders, so I just trim on my normal cutter using a pressure pad held to the clamp. It's just a hard pad with a magnet on which I position on the clamp. I then make sure when I cut books, the pad holds the books just to the side of spine, so the spines are never clamped. The only things you have to do then are make sure your blade is sharp and the you flip the books so you are always trimming with blade travel towards the spine to prevent the cover from tearing or nicking. Not great for big orders, but works well for me.

 

[Buntpapier]

Hi max.lee, hi easiprint!

@ easyprint
Yes, it is absolutely right the flat clamp is reducing the spine in the height. This will cause damage.
The magnetic height compensation works. But I do not like it, because the magnet includes iron. And this is not good for the knife. I prefer to put an industrial felt with a thickness off 0.5 to 1 cm underneath the clamp. You may use double side adhesive tape to position the felt underneath the clamp. If you leave the felt a bit bigger the knife cuts the felt of perfectly. Industrial felt is not expensive and everywhere available
The positioning of the book in the machine is correct as well. The knife should cut from the outside into the spine. Therefor I like the felt as well. A clamp in a shape smaller of the boog will not hold the clamp down and the sidewise swinging knife move the spine a bit. At the end you have a heigh risk of an not straight cutting edge.

@max.lee
If your machine has one knife only and cuts all the three sides of the book, you will have something like a gripper to turn the book and a flat clamping bar. In these machines you can use something soft underneath the clamp. Maybe you can start with an old rubber blanked. This would give you an height compensation of about half a millimeter. Maybe it is already enough. For more compensation as well felt or caoutchouc (natural rubber) based products like Cellasto or equivalent plastic materials works fine.

Best regards
Buntpapier

 

[halmac]

We buy the rubber pads with a magnetic back from our cutter supplier. We notch out the rubber about 3/8 inch away from the spine on both sides. You will need to make one for each size book you make. Clamp pressure should be a minimum also.
You can make your own pads using carpet underlay.

 

[Mstrkey]

crushing the spine

crushing the spine

We buy the rubber pads with a magnetic back from our cutter supplier. We notch out the rubber about 3/8 inch away from the spine on both sides. You will need to make one for each size book you make. Clamp pressure should be a minimum also.
You can make your own pads using carpet underlay.

You can easily just cut a stack of scrap paper that's thicker than the difference between the spine of the book(s) and the cut egde. Just slide it under your cutter clamp on each cut. You can tape the stack of paper together for easier handling. So your books will be on the bottom, scrap paper on top. This way the cutter will clamp down on the scrap paper and leave the spine of the books untouched. It's a bit of a pain but it's free.

 

[max.lee]

Hello Guys,

Thank you all for the feedback, i wasnt able try the solutions as i send my knife for sharpening.

After reading the comments and try to put something and not touching the spine, it actually works.

how i did was to put a a3 saddle booklet on top of the booklet and not touching the spine, thus the pressure is being distributed to the other areas instead of the spine.

Thank guys for the wonderful feedback.