Bell Skiver Frustrations!!!!

[MtlBiker]

I just don't know what I'm doing wrong or have wrongly adjusted...

I'm new to using a bell skiver, and I practiced with scraps for awhile and after scrapping lots of those scraps I was finally ready to skive pieces for my bags.  I did really well, and I was ready for the big time.  I used some 4oz +/- chrome tan leather in red and in black.  I had to readjust a little bit when I changed to the black from red.  But everything worked.  Then two things happened:

First of all I sharpened the bell knife and I'm pretty sure I did that correctly, thanks to lots of videos.  I did pretty much what @RockyAussie suggested in the video he just posted.  In any case, I hadn't skived all that much leather and the knife probably was still pretty sharp.  But I wanted to go through the process anyway.  The second thing that changed was that I got a new batch of black leather which wasn't quite the same thickness (maybe 3.5oz instead of 4) as before and it felt, I guess I would describe, softer.  In any case, I ran a few test strips and adjusted until I was getting about half the original thickness after skiving. 

Then I started skiving my cut pattern pieces.  I started with what I thought was going to be easy... the rectangular pieces, saving the ovals for later.  I first skived the two short ends.  Then as per some videos I'd seen, and the way I successfully skived the first red and black pieces, I lifted the presser foot, placed the long side of the rectangles down and lowered the presser foot.  And started skiving.  Well, I ruined (chewed up) 4 of the first 8 pieces.  I left it at that point because I was going to break something and I went for dinner and a martini.

Today I cut new pattern pieces to replace what I'd destroyed yesterday.  I re-checked adjustments and found the space between the feed stone and the bell knife was too large.  (Don't know how that happened.)  Then I found the spring holding that assembly (sorry, not sure what it's called) wasn't strong enough to let the feed stone all the way up to where it should have been.  So I cranked that up a few notches.  Re-adjusted (using a piece of bond paper) and then I skived the short edges of a piece.  So far so good.  Then I tried to skive the long edge and again destroyed the leather!  I have no idea what I did wrong or what adjustment might be off.  I don't know where to start in diagnosing this.  All I can say is that the leather I bought is expensive and I'm ruining it.  And what's left of those pieces after I ruin the edge isn't enough to use in any other part of these bags.  Total waste, except that I can cut strips out of it in order to test the skiving.  Frustrating, with a capital F.

Are there any suggestions you folks might have as to what I might be doing wrong or what isn't adjusted correctly?  Thanks!

 

[toxo]

At a guess I'd say the feed roller isn't close enough and looking at the repetitions of the chew ups you might have a piece of leather stuck on the feed roller so every revolution you get a different skive thickness at that point. Looks like you started off slow and then went faster.

[Spyros]

Bell skiver sounds like the kind of thing you only master in your 60's LOL

[RockyAussie]

6 hours ago, MtlBiker said:

I just don't know what I'm doing wrong or have wrongly adjusted...

I'm new to using a bell skiver, and I practiced with scraps for awhile and after scrapping lots of those scraps I was finally ready to skive pieces for my bags.  I did really well, and I was ready for the big time.  I used some 4oz +/- chrome tan leather in red and in black.  I had to readjust a little bit when I changed to the black from red.  But everything worked.  Then two things happened:

First of all I sharpened the bell knife and I'm pretty sure I did that correctly, thanks to lots of videos.  I did pretty much what @RockyAussie suggested in the video he just posted.  In any case, I hadn't skived all that much leather and the knife probably was still pretty sharp.  But I wanted to go through the process anyway.  The second thing that changed was that I got a new batch of black leather which wasn't quite the same thickness (maybe 3.5oz instead of 4) as before and it felt, I guess I would describe, softer.  In any case, I ran a few test strips and adjusted until I was getting about half the original thickness after skiving. 

Then I started skiving my cut pattern pieces.  I started with what I thought was going to be easy... the rectangular pieces, saving the ovals for later.  I first skived the two short ends.  Then as per some videos I'd seen, and the way I successfully skived the first red and black pieces, I lifted the presser foot, placed the long side of the rectangles down and lowered the presser foot.  And started skiving.  Well, I ruined (chewed up) 4 of the first 8 pieces.  I left it at that point because I was going to break something and I went for dinner and a martini.

Today I cut new pattern pieces to replace what I'd destroyed yesterday.  I re-checked adjustments and found the space between the feed stone and the bell knife was too large.  (Don't know how that happened.)  Then I found the spring holding that assembly (sorry, not sure what it's called) wasn't strong enough to let the feed stone all the way up to where it should have been.  So I cranked that up a few notches.  Re-adjusted (using a piece of bond paper) and then I skived the short edges of a piece.  So far so good.  Then I tried to skive the long edge and again destroyed the leather!  I have no idea what I did wrong or what adjustment might be off.  I don't know where to start in diagnosing this.  All I can say is that the leather I bought is expensive and I'm ruining it.  And what's left of those pieces after I ruin the edge isn't enough to use in any other part of these bags.  Total waste, except that I can cut strips out of it in order to test the skiving.  Frustrating, with a capital F.

Are there any suggestions you folks might have as to what I might be doing wrong or what isn't adjusted correctly?  Thanks!

 

With some leather they have a loose top surface and that generally runs through in the same direction through the hide. This I think is something that is caused at the tanning stage when the put the skin through rollers to apply coating or to soften and break up the tension in the hide. To the left in your picture above you see a saw cut appearance and that is a sign of a small chip in the blade. The chopping out like that is most likely the top loose skin moving as it tries to feed itself through. The skin top gets pushed back by the presser foot and that creates an extra thickness that then gets pushed down into the blade cutting all the way through until that thick bit is gone and again and again until you get back onto firmer leather. Its a bitch yeah I know but it can be less of a problem with a roller presser foot. Also less spring pressure on the feed. Also some wax polish or silicon spray on the top to reduce the friction of the foot. ALSO a VERY sharp blade. Run a piece of medium temper leather (DO NOT ask me to explain that) through VERY slowly. This sort of acts like you are stropping the edge by smoothing out any rough bits from the sharpening stone. If your bell drive is not separated from your feed that may not work so well. Please post some pictures of your machine if you keep getting any more problems. Mostly where the spring adjustment pressures are and feed stone to bell relationships are laying etc. ( everyone goes through this at the start so do not expect that you will get it all right from the get go)

Last thing...on soft leather make sure that you have a wide bevel on your bell edge as in about 4mm from the presser foot edge as shown below. Any less and the extra pressure required to push the leather through will give you more chopping out as well.

If the blade is sharp and you don't have about 4mm then you either need a new sharpening stone that is bigger and rounder or you need to move the sharpening stone back as shown in the pictures below.

The bolt to loosen

Note the gap below is about 2 or more mm.

Here the gap is fully in but I would not move more than 1mm to start with on a fairly new sharpening stone

Make sure that the stone is squared up to the bell edge when you tighten it.

Disclaimer.....if you cut yourself or whatever else whilst doing this ...............someone else wrote all of this. BE CAREFUL around sharp or hot sh.t OK.

.

[MtlBiker]

12 hours ago, toxo said:

At a guess I'd say the feed roller isn't close enough and looking at the repetitions of the chew ups you might have a piece of leather stuck on the feed roller so every revolution you get a different skive thickness at that point. Looks like you started off slow and then went faster.

By "feed roller" you mean the football shaped feed stone, right?  I ask because some people seem to be using a roller presser foot.  There wasn't any leather stuck anywhere.  As far as starting off slow and going faster, I'm not pulling the leather at all, just guiding it.  It's the feed stone that's doing the pulling.

Anybody want to buy a very little used bell skiver? 

(Just kidding of course!)

 

9 hours ago, Spyros said:

Bell skiver sounds like the kind of thing you only master in your 60's LOL

Darn!  So I'm too late then.  SIGH

 

 

[MtlBiker]

7 hours ago, RockyAussie said:

To the left in your picture above you see a saw cut appearance and that is a sign of a small chip in the blade.

I'll try to resharpen then.  But gee, the blade was doing fine and the whole thing was new and I'd only skived less than 20 pieces (no bigger than about 8 x 15 inches).  And I'm pretty sure (novice that I am) that I did the sharpening correctly.  I'll try again.

8 hours ago, RockyAussie said:

Also some wax polish or silicon spray on the top to reduce the friction of the foot.

Sorry for being dense, but on the top of what?  You mean on the bottom of the presser foot, or something else?

8 hours ago, RockyAussie said:

If your bell drive is not separated from your feed that may not work so well. Please post some pictures of your machine if you keep getting any more problems. Mostly where the spring adjustment pressures are and feed stone to bell relationships are laying etc.

Unfortunately the feed and bell drive are not separate.  And as far as the spring adjustment goes, one thing I noticed last night was that unless I used one of the tightest notches, there wasn't enough pressure to bring the adjusting screw to the stop, so the feed stone gap to bell knife was too large.  I don't know what/why that is, because it wasn't like that earlier.  It used to be fine even on the first (lightest) notch.  I'll examine more closely tonight when I get home.

8 hours ago, RockyAussie said:

Last thing...on soft leather make sure that you have a wide bevel on your bell edge as in about 4mm from the presser foot edge as shown below.

I have no idea how wide the bevel is on my bell knife.  I'll check that tonight.

 

8 hours ago, RockyAussie said:

Note the gap below is about 2 or more mm.

Not quite sure where on that photo that gap is.

---------------------

Your help and patience is greatly appreciated!  Thank you so much!

[RockyAussie]

17 hours ago, MtlBiker said:

I'll try to resharpen then.  But gee, the blade was doing fine and the whole thing was new and I'd only skived less than 20 pieces (no bigger than about 8 x 15 inches).  And I'm pretty sure (novice that I am) that I did the sharpening correctly.  I'll try again. (some leathers get tanned differently to other leathers and some can be very nasty on the blade edge and some are very mild and you can go for hours without resharpening. Some tanning processes like Allium tanning are very nasty on any type of splitting, cutting or skiving. Most likely your setting are not ideal as yet and that can be very nasty on your bell edge as well. 

Sorry for being dense, but on the top of what?  You mean on the bottom of the presser foot, or something else? (My meaning was on top of the leather.)

Unfortunately the feed and bell drive are not separate.  And as far as the spring adjustment goes, one thing I noticed last night was that unless I used one of the tightest notches, there wasn't enough pressure to bring the adjusting screw to the stop, so the feed stone gap to bell knife was too large.  I don't know what/why that is, because it wasn't like that earlier.  It used to be fine even on the first (lightest) notch.  I'll examine more closely tonight when I get home. (something is for sure wrong there. If you can not find it please post some pictures from underneath along the lines as I suggested previously)

I have no idea how wide the bevel is on my bell knife.  I'll check that tonight.

 

Not quite sure where on that photo that gap is. (where the shaft can slide in and out as shown with the arrows in the edited new pictures)

Fully in shown = very wide bevel

About 2mm out = steeper bevel

 

 

 

[RockyAussie]

On 4/30/2022 at 3:07 PM, Spyros said:

Bell skiver sounds like the kind of thing you only master in your 60's LOL

Could be right there. Hope I reach that status before I get to my 70's though.

[toxo]

18 hours ago, MtlBiker said:

Darn!  So I'm too late then.  SIGH

 

 

Me too.

[MtlBiker]

10 hours ago, RockyAussie said:

My meaning was on top of the leather.

I hadn't realized you were suggesting putting wax on the leather itself.

I tried readjusting everything and making sure there was no debris caught anywhere.  I want to scream!  I skived one small piece and when I tried to skive the long edge of that piece, it got chewed up at the end.  I don't pull the leather... just let the feed stone move the leather through.  Then I thought the gap between the feed stone and the bell knife might have been a bit too large, so I re-adjusted that, using a piece of bond paper to get it tighter and even.  I then skived successfully four more small test pieces and I was ready to skive a piece for production.

Sure enough, even when I tried to skive the first short side, the leather got chewed up.  SIGH  Talk about frustration!  I checked and there was no debris around the feed stone and I couldn't see anything wrong.  I had to put that all aside for now, and will go out and do some yard work instead.  Before I smash something. 

I don't know if it'll help, but here are some photos... 

 

IGNORE this last Sailrite photo... I inserted it by mistake and cannot find how to remove it. 

"Removed it for you"

 

Edited May 1, 2022 by Northmount
Remove unwanted photo

[Northmount]

3 hours ago, MtlBiker said:

cannot find how to remove it

Scroll all the way to the bottom, to the uploaded photos, click the garbage can on the lower right of the photo.

[MtlBiker]

2 hours ago, Northmount said:

Scroll all the way to the bottom, to the uploaded photos, click the garbage can on the lower right of the photo.

Thanks very much!  I didn't see any garbage can icon... are you talking about before I submit the message, or afterwards via edit?  Before submitting it, I tried all kinds of things and must have missed the garbage can.  And though edit, likewise, I didn't see that.

[Northmount]

3 minutes ago, MtlBiker said:

Thanks very much!  I didn't see any garbage can icon... are you talking about before I submit the message, or afterwards via edit?  Before submitting it, I tried all kinds of things and must have missed the garbage can.  And though edit, likewise, I didn't see that.

It's there under edit for me all the time.  May not be there for you all the time, besides your limited time window for editing.  The icon is light gray.

 

[alpha2]

On 4/29/2022 at 11:07 PM, Spyros said:

Bell skiver sounds like the kind of thing you only master in your 60's LOL

Oh, I don't know...I'm 68 now, and am just now, reading all this, glad I never went crazy and bought a bell skiver! It always SOUNDED like a good idea! I swear, I managed, when I was working, to install and calibrate all manner of high tech, digital, 3d, cone beam, volumetric tomographic x-ray equipment, but my Cowboy 4500 gets slightly out of time, and I'm all thumbs. If I didn't have our amazing resources, (you know who you are!) and their youtube videos, I'd buy a really big boat, and use it for an anchor. I don't have any idea what people did before the internet. I likely had an idea, years ago, but I've forgotten. (Remember libraries? Neither does anyone else!)

I just discovered, that you can have cheap Tandy leather, and a REALLY sharp head knife, or a REALLY good leather, and a maybe almost sharp head knife, but you can not, under any circumstances, have cheap Tandy leather and an almost, not quite sharp head knife. I have determined though, that Tandy leather needs to be cut with a hacksaw. A SHARP hacksaw. Still learning at my advanced age.

[RockyAussie]

A video of you prior to feeding and then feeding in some leather would help. For now I think that your feed stone is too lowly angled at the front. Your presser foot is angled down too much so that it cuts in a hollow more so than the outer edge. Your presser foot has been shaved and perhaps not polished enough. First up here is an edited picture of your leather sample above

This picture shows that your feed stone has too much gap at the front -

Mine for you to compare -

Showing what to adjust- turn front knob clockwise firstly in your case.

 

 

 

[MtlBiker]

@RockyAussie - What a great and oh so helpful reply!!  Thank you!  I am off today (my weekend is always Sundays and Mondays) and I will readjust as per your instructions.  You are really a prince for your kind and patient help!

 

Edited May 2, 2022 by MtlBiker
spelling

[MtlBiker]

@RockyAussie - I'm making progress, but only a little bit.  I was surprised that my presser foot was so tight that I had to use pliers to loosen the retaining knob.  And it was so tight that it wasn't even touching the back stop (It wouldn't pivot at all) so the adjusting screw wasn't even reaching it.  I've fixed that, and am trying to make the feed stone parallel with the bell knife and I think I've got that.  I've also brought the feed stone up evenly to just shy of the bell knife.  Still chewed up the leather.  I guess I'll try backing off the presser foot pressure (but that'll reduce the skive amount, right?) and see what that does.  I did change the angle of the presser foot to the bell knife (improved it I think).

I'm not quite sure how to make the space between the feed stone and the bell knife the same all along... I put a piece of paper in and it seems to be the same.  Should I maybe move the feed stone away from the bell knife and THEN insert the paper?  And then try to feel how easy/hard it is to pull it out?  And try that at the front and back of the stone?

I'm going to have to sleep on it and try again tomorrow night after work.

[RockyAussie]

11 minutes ago, MtlBiker said:

(but that'll reduce the skive amount, right?)

Lighter spring pressure (the hook thing on the side) will let the leather push the feed stone down more easily so in fact it should skive out more. That could mean that you may then need to raise the presser foot up so as to not take out too much when you run the leather through.

 

18 minutes ago, MtlBiker said:

I put a piece of paper in and it seems to be the same.  Should I maybe move the feed stone away from the bell knife and THEN insert the paper?  And then try to feel how easy/hard it is to pull it out?  And try that at the front and back of the stone?

You could do all that but you should be able to see by eye fairly easily as in the picture of mine compared to yours above. If it gets too close to the bell with the feed running you should hear it quite easily. If you let it do that too much it will ruin the edge of your bell and the leather will always want to dive in and cut holes in your job. That said I often will let it touch very very lightly for a couple of seconds if I am cleaning up a heavy burr after a heavy sharpening. Crocodile has bones in it sometimes around the flank areas and that can take a good chip out of the bell edge which then takes a fair bit to sharpen back to level again. I am not sure if your edge is sharp or not but as I said do a video of the leather running through and I may be able to advise from there. A bell is NOT sharp if the leather wants to pull back away from you when it is being fed through. With soft leather if you push it up against a blunt bell or a bad presser foot or too tight a spring presser it will concertina up and that makes it chop out hollows and holes.