making obsolete parts for machines

My day job is working for a small print shop (the 2d kind). We print business cards, invoice books, flyers, banners, postcards, and a variety of other things...

We recently had an order for some "record books" for farmers to track livestock, machinery and other items related to running a farm. These books were to be bound with the "cloth" spines - basically a strip of cloth impregnated with glue that holds the book together.

We have a special, small machine for doing these - old, but still very functional - for the most part. The book is placed in a slot at the top of the machine, a binding strip is fed in from the side, it is then heated and pressed around the spine of the book.

As it turns out, the rubber wheel that pulls the binding strip in had deteriorated to the point that it was not pulling the strips in straight anymore, and causing more problems than actually finishing books.

Boss ordered what he thought was a replacement wheel for it... what arrived was not the same, and after a phone conversation, it was determined that we would have to spend several hundred dollars to "upgrade" other parts to make the new wheel work in this machine. Not really a justifiable expense for the infrequency of use - not to mention that we needed to get these books finished and out the door in a matter of a couple of days.

After looking at it carefully, I suggested that I could 3d print a piece in TPU to replace the rotten rubber of the old wheel... I was taken up on the offer. Boss figured we had nothing to lose in trying.

So I brought the old part home that night, made some careful measurements, modeled the part, and printed it out. Took the printed piece and the original part back to work the next morning and handed to the boss. After looking it over, he made the call of cutting the old rubber part off, pressing the new TPU part on, and putting it back in the machine.

We honestly had no idea if the TPU was going to hold up in use - it does get pretty hot inside that machine and apparently some TPU has very low temp thresh holds (this from a materials friend of mine) - but after getting it installed, a few "test" books were run and it appeared it was going to work. A few minor adjustments to get the binder strip to align correctly on the book, and we were off and running.

750 books later, I am pleased to say the TPU part is holding up very nicely. the picture of it in the machine was after finishing the books - it looks just as good after as it did before.

The specific brand of TPU I used is Sainsmart, in grey.

Boss was so pleased, he ordered 2 more to have on hand, LOL (and yes, I was paid for this)