Skiving Machine ripping my leather

[SonderingSusan]

Hi Everyone,

 

I was wondering if anyone would have some feedback for me in relation to my skiving machine. I am struggling to lear to use it and    twice today as i skiff along the edge of work the machine has ripped the good side of the leather. What could be wrong here? All/ any help with this would be greatly appreciated. I looked it up online and can't find and info about skivers really at all. Thanks all !

[Thor]

A picture tells more than a thousand words...

[SonderingSusan]

HI Thor,

 

 

Thanks for replying to me. I have enclosed two pictures of the rip in question below. What do you think?

Thanks,

Sus

[Thor]

Just a guess, but I would assume that it didn't just rip. Guess what happened is that the leather "kinked" and didn't stay on the roller at that time. I stopped skiving this kind of leather and instead fold it for that same reason. It may just be practice as with most things, but I just didn't feel a need to skive such thin material. May not be correct, but haven't had an issue with it yet. Maybe someone else chimes in.

[SonderingSusan]

Thanks for your help with Thor. 

 

Is there a possibility that my bad is not sharp enough do you think ?

[Thor]

Honestly I don't know, but whenever there's a knife, blade... there's a chance that it's not sharp enough or becomes dull with use. 

[Ferg]

The bell knife must be sharper than anything you can normally imagine, especially when trying to skive already thin leather.

I have a skiving machine and have, quite frankly stopped skiving the thin leather. I prefer doing it with one of my round knives the Knipper made for me. I can accomplish a much better skive on the thin stuff and do it more quickly without worrying about the "tear out". Thin leather stretches. I have been able to do some by holding onto the leather from both sides/edges, it simply isn't worth the expense of wasting what is usually expensive leather plus the time involved.

Ferg

[SkullCanyon]

I agree with Ferg, your blade may seem sharp, but not sharp enough. Bunched up thin leather causes this every time. I have ruined a lot of leather learning this myself.

I use a weight on the foot pedal and let it sharpen away for 20 minutes sometimes to get a good cut. Hand skive your thin leather for best results.

Good luck

[SkullCanyon]

 

[Nuttish]

Assuming you have a Fortuna type machine.

On the point of sharpening, it's easy to be mistaken about whether you're actually dressing the edge at all rather than hitting the back or center of the bevel. It's helpful to run the machine with a marker over the bell knife so you can then see where the wheel is removing color as it grinds. It's ok to just start over and put a new edge on. Just make sure you grind the new bevel from the back to edge. The Fortuna manual recommends an OEM carborundum stick to roll the burr on the inside of the bell knife over after sharpening, but the smooth end of a high speed steel drill bit will do a fine job if you very very carefully, very very lightly, and very very quickly touch it to the inside of the bell knife. 

You may also be getting a jagged edge because your grinding wheel is dished out in the middle. If your machine still has the diamond dressing tool inside the left cover, you can knock the edges off to get a relatively flat grinding surface.

Another problem that can contribute to premature knife dulling is slop in the linkage between the back gear box and the bushing or bearing the close end of the feel roll spindle rests in. It can slap around and occasionally hit your knife when you're working close to the presser foot. If this is the case, you'll just need to order a replacement part.

[RockyAussie]

What type of skiver have you got?

A picture of the machine close up to the foot and the feed wheel would help a lot to best answer your problem.

Soft spongy leather will often not feed through without occasionally gathering up and doing this problem. A (little) silicone spray will help.I have a fortuna and a fav but because of the scraping I got with normal feet on glazed crocodile I have adapted up feet to have a brass roller at the front part of the foot shaped opposite in shape the feed roller. This then rolls instead of sliding and helps a fair bit with soft leathers as well. Also I have replaced the steel grooved feed wheels with the fine stone type. After sharpening and before skiving soft leather get some middle firm scrap and very slowly take it through this help to smooth out any roughness a bit like polishing your knives after sharpening. If you need pictures let me know. Hope this is of some help.

Regards Brian F