Sagitta Skiving Machine - Manual wanted

[AtelierStefani]

Hi there,

I purchased a Sagitta leather skiving machine but didn’t get a manual with it.. There are some wrong settings set on it, so it doesn’t properly work, yet. The manufacturer is not responding to my emails either.. Can someone help? 
 

The model no. is: SK 05 C R2

Serial no.: 0520143

Construction year: 2018

Attached is a technical sheet of the machine. It runs on two separate motors for knife and feeding mechanism.

I’d be so grateful if someone could help me out with the right manual or ‘a’ manual that could work. 
 

Thanks a lot!

[Tigweldor]

Have you tried it directly through the manufacturer´s homepage ?

https://www.sagitta.it/en/assistance/

 

[mbnaegle]

I've got a PDF manual for an older model (SC75) but not that one. It looks like other than the table and motor configuration, it's a typical bottom feed skiving machine that will adjust and operate same as others like Fortuna, FAV, and Atom. Here's some basics for anyone trying to dial in one of these skivers.

I find that a good starting point is the blade position and sharpness. For light to medium weight leathers, you want the blade to be about a business cards width (.3mm to .4mm) away from the right side of the foot. If its under the foot or right at the edge, material will jam instead of cut. For denser heavier leathers, more gap is necessary as they don't bend up over the blade as easily, and it takes some trial and error in those case to find the right gap setting. Too much of a gap and the material will cut easily, but not accurately.

Blade sharpness is always key. It's not something you can do on a time basis, or in other words, you can't just sharpen for 5 minutes and say you are done. Use the machines performance with your material or jobs to govern how often and how long you sharpen. If the cut leaves lines parallel to the blade, or burnishes as it's cutting, it's dull. It's a single bevel blade and the grind stone only hits the outer edge, so periodically you'll need to dress the inside corner with a fine stone (often sold specifically for this job) to take the burr off. Once the blade is sharp, it takes very little to maintain the edge. You might only sharpen for 30 seconds between jobs, or keep it lightly sharpening while you are using the machine. Think of every piece of leather going through it as slightly dulling the blade and your sharpening routine is trying to keep up with it.

Also note that the condition of the grind stone is important. It needs to be dressed frequently based on it's performance, using a grind stone dressing wheel or carborundum stick. If you see a shiny metal build up around the stone, dress it. If you see a spray of sparks but no sparks are going around the stone, dress it. If you hear it sharpening before you see sparks and have to increase pressure on the grindstone to make sparks, or doing so causes it to bog down (can also mean the belt is bad), dress it. The stone and blade are meant to be expendable, so don't be afraid to sharpen and dress if your job demands it. It's common to need to sharpen as you are using the machine, and it's better to sharpen lighter and more often, then really heavy all at once, as doing so will cause more heat that can effect the temper of the blade and also produces are more ragged and less defined edge.

After your blade is in position, adjust the bottom roller height and angle so that the roller is as close as you can get it to the blade without the two touching. If you are using a stone or metal roller, you can adjust it until there is very little visual gap, then with the machine running slowly adjust it up until you hear the roller "tick tick" against the blade and back it off a little. If you are using a rubber roller (better for really fine precise work), don't let the two touch as the blade will cut the rubber. In that case you can use a piece of paper to set the gap. Some thicker materials, or special shapes may benefit from having the roller set lower, but most you want it at the top of it's travel. The spring pressure adjustment for both roller movements needs to be firm enough to pull the roller to the top of it's adjustment, but not so stiff that the material has a hard time pushing the roller down to go through.

The foot selection and adjustment is all about the shape you want to cut, while blade and roller position are about getting the material to cut well.

[Tigweldor]

What is also ABSOLUTELY and VERY important : after grinding the bell knife with the built in stone sharpening wheel - you have to dress the the inside of the bell knife with a hand held device as well  ---  to remove the burr has has formed.

If you do not do that - the bell knife will still feel dull - and tends to tear/shred the leather.

Now with that hand held device you don´t have to get fancy - a strip of sandpaper (better is emery cloth) draped over the tip and back on a round (chainaw) file or screwdriver will suffice.

Even the naked round chainsaw file can be used - after  a while of use though, you have to cut off the tip with a grinder - cause the file is only being used on a very short part of it at the tip = limited file flutes in action. They clog up and wear fast because the bell knife spins so fast.

A small round sharpening stone or a round industrial diamond coated file will naturally work better/easier - but anything is better than leaving the burr.

If you want to get your bell knife really sharp - you will have to repeat this double action sharpening sequence a few times with ever smaller getting advance setting on the grinding wheel - as the burr will have a tendency to just flip onto the other side until it gets so thin, that it breaks off.

At that point you will have attained utmost sharpness.

And WATCH YOUR FINGERS when doing this - skiving of a part of your finger is no fun - a spinning sharp bell knife will cut right through bone.

 

Greetings

Hans

Edited May 1 by Tigweldor