cobra Bell Skiver, Top and Bottom Feed,

[RockyAussie]

2 hours ago, Silverd said:

Why do you suggest a vacuum system is helpful?

Most leathers except greasy/waxy saddlery type leathers will stick a little to the stone or feed wheel that the presser foot pushes it down into aqnd that very often leads to the waste piece coming back up and ruining the leather you are skiving. Some of these machines use a wiper piece to try and stop that happening but the pressure it puts on the part often destroys and because the part that holds it is also on a spring pressure control it then upsets preciseness of the skive as well. The vacuum assist greatly in taking the waste away and avoiding this problem. I have had both with and without vacuums and I would NEVER have another one without vacuum. Other than the video above that is mostly doing leather pieces not long enough to come back up and around I ask you if you can find any other videos where you don't see the leather coming up and around at times that is not a vacuum type. This is even on dealers videos selling these machines. Believe it or not.

Techsew and Campbell Randall both sell skivers with vacuum assist and Campbell Randall have a good range of feet and other stuff which can go on most of these model skivers. Most of it is in the FAV machine section but they are interchangeable with most others.

[Silverd]

Everything you are saying makes sense.  I have a LAndis 5 in 1 with a skiver and it also does as you describe.  Hate the Techsew idea.  Ive had a problem with them since the start and I started with them so there you go.  But I can deal with Campbell and will give them a call.  My surprise is that there is so little information about the details of a bell skiver that it would be very easy to make a wrong decision.  Cobra has been really pushing the NP-10 top and bottom feed and that would be fine if I were working heavy leather for saddles etc...but I have been clear to them that my work is light...3-4 oz herman oak...Bag making which I guess may not be understood as to the requirements. But seeing the various presser feet that Nipppy demonstrates in the reference video is exactly what I can use.   Maybe not all of the variations but I would buy them all if I had to.   I have only seen one presser foot intended to replace the feed roller on a top feed machine...not that more could not be designed and machined but that's not my objective.  

 

Thank you for your input.  I think based on what you told me I will add a Vacuum feature to my bottom feed skiver criteria.  

 

Silverd

[Arturomex]

Good choice.

I can't speak for others but I think a bell skiver is one of the best investments I've made in a long time. I hope you'll feel the same way.

Please, keep us posted.

Regards,

Arturo

[jimi]

7 hours ago, Silverd said:

Thank you for your input.  I think based on what you told me I will add a Vacuum feature to my bottom feed skiver criteria.  

If you need a manual, PM me your email and i can send you one.

[keithski122]

I found that my skiver(no vacuum) would pull the waste back up around the feed wheel, I've since changed the stone wheel for a yellow rubber one and this(so far) has completely solved this problem.Saved me a lot of work in fitting an aftermarket vacuum.I think it also has made the feed easier or smoother, a very worthy modification.

[Silverd]

17 hours ago, RockyAussie said:

Most leathers except greasy/waxy saddlery type leathers will stick a little to the stone or feed wheel that the presser foot pushes it down into aqnd that very often leads to the waste piece coming back up and ruining the leather you are skiving. Some of these machines use a wiper piece to try and stop that happening but the pressure it puts on the part often destroys and because the part that holds it is also on a spring pressure control it then upsets preciseness of the skive as well. The vacuum assist greatly in taking the waste away and avoiding this problem. I have had both with and without vacuums and I would NEVER have another one without vacuum. Other than the video above that is mostly doing leather pieces not long enough to come back up and around I ask you if you can find any other videos where you don't see the leather coming up and around at times that is not a vacuum type. This is even on dealers videos selling these machines. Believe it or not.

Techsew and Campbell Randall both sell skivers with vacuum assist and Campbell Randall have a good range of feet and other stuff which can go on most of these model skivers. Most of it is in the FAV machine section but they are interchangeable with most others.

I contacted Campbell this morning and talked with them about the FAV AV-2 skiver.  They handle these products but don't stock them and wait time due to Italy on summer break will be into October or possibly November depending on how soon FAV could ship.  They also recommend a rubber roller to deal with the wrap around issue in place of a vacuum system which drives cost up another $2k.  And they recommend the dual drive control that turns the bell knife at a constant rpm and allows speed adjustment of the feed roller by the operator.   I think that sounds like a practical Idea however cost on this machine was estimated at $4500 delivered to CA.   That's a bit more than I would like to pay and a lot longer than I want to wait. 

I think there is likely a lot of successful skiving being done using the simple clones.  No vacuum, no dual control, no top feed, not OEM for less than 1/2 the cost of a FAV or a Nippy or Fortuna etc and likely support of the Clone machines from a reputable source is far better than the OEM makers.  A strange industry this sewing bunch.

 

Silverd

[RockyAussie]

On 8/8/2020 at 4:50 AM, Silverd said:

A strange industry this sewing bunch.

On 8/8/2020 at 4:50 AM, Silverd said:

I contacted Campbell this morning and talked with them about the FAV AV-2 skiver.  They handle these products but don't stock them and wait time due to Italy on summer break will be into October or possibly November depending on how soon FAV could ship.  They also recommend a rubber roller to deal with the wrap around issue in place of a vacuum system which drives cost up another $2k.  And they recommend the dual drive control that turns the bell knife at a constant rpm and allows speed adjustment of the feed roller by the operator.   I think that sounds like a practical Idea however cost on this machine was estimated at $4500 delivered to CA.   That's a bit more than I would like to pay and a lot longer than I want to wait. 

I think there is likely a lot of successful skiving being done using the simple clones.  No vacuum, no dual control, no top feed, not OEM for less than 1/2 the cost of a FAV or a Nippy or Fortuna etc and likely support of the Clone machines from a reputable source is far better than the OEM makers.  A strange industry this sewing bunch.

 

Silverd

Keep in mind that most dealers do not use these machines every day and would have little idea of the differences between the different models.

Most of the cheaper clones are running a set up similar to what Fortuna stopped making around 50 years ago. The bell knife cutting only starts when the feed stone starts and that means also that when you want to feed the material through slowly then the bell knife also turns slowly and that does not work so well. It is common for people to solve this by putting in a second motor to have the bell run fast and the feed run independently. The FAV AV 2 you mention above already has a clutch motor similar to the Fortuna (I have one of each) and at the back there is a knob which can be set to have the feed run at whatever speed you want if you ever want it to run at a set speed continuously. IF you expect to use a skiver a LOT spend the extra $ early or learn the hard way as I did. Last note.....the rubber feed wheels do not go well if you mistakenly allow it to contact the bell knife while adjusting. It slices it and kaput. With a feed stone you can make a light contact and get rid a any coarse burring when you are doing a heavy sharpening process. Having a vacuum also takes a lot of waste away to the side without any need for it to drop down at your feet or the need to try and position a catching bucket etc. Personally I would be looking for a good condition 2nd hand Fortuna.

[Silverd]

23 hours ago, RockyAussie said:

Keep in mind that most dealers do not use these machines every day and would have little idea of the differences between the different models.

Most of the cheaper clones are running a set up similar to what Fortuna stopped making around 50 years ago. The bell knife cutting only starts when the feed stone starts and that means also that when you want to feed the material through slowly then the bell knife also turns slowly and that does not work so well. It is common for people to solve this by putting in a second motor to have the bell run fast and the feed run independently. The FAV AV 2 you mention above already has a clutch motor similar to the Fortuna (I have one of each) and at the back there is a knob which can be set to have the feed run at whatever speed you want if you ever want it to run at a set speed continuously. IF you expect to use a skiver a LOT spend the extra $ early or learn the hard way as I did. Last note.....the rubber feed wheels do not go well if you mistakenly allow it to contact the bell knife while adjusting. It slices it and kaput. With a feed stone you can make a light contact and get rid a any coarse burring when you are doing a heavy sharpening process. Having a vacuum also takes a lot of waste away to the side without any need for it to drop down at your feet or the need to try and position a catching bucket etc. Personally I would be looking for a good condition 2nd hand Fortuna.

Good advise.  According to the Cobra team in Ontario California, the NP-4 skiver can be set up to run two motors. one foot pedal variable speed for the drive wheel, one adjustable but constant rpm for the bell knife.  There is an added cost of about $225.00 to install the 2nd motor and belt etc. which seems reasonable to me.  The machine does not have a feature to accommodate a vacuum system but it would not be difficult to add a vacuum hose through the bottom of the table under the cutting zone since these machines are open on the bottom.   I like your idea of the stone that can be used to remove burrs...and Dave at Cobra sent me (on request) a photo file of the various presser feet that Cobra sells for the NP-4.  There are 13 in total different feet,  none of them however are roller style like the Nippy examples in the above Nippy made video.  Perhaps another skiver makers roller feet will fit it.  I've since given up on buying a Nippy due to the difficulty in communicating with them.   I would be interested in a used Fortuna Skiver,  as you suggest as these machine have all of the features I believe to be desirable, but I have not found one for sale in the USA.   The Cobra solution seems to be the best alternative and would be supported into the unforeseeable future.   Cost of a new Cobra NP-4 is also a consideration as they are quite reasonable and the Cobra products in general appear to be of good workmanship compared with other Chinese clone machines.   

Silverd

[RockyAussie]

Have a look in here and you will find all sorts of stuff like those roller presser feet and feed rollers etc - https://www.campbell-randall.com/shop/fav-fratelli-alberti?page=8

As to the vacuum...... the machine has to have an end covering to get the vacuum to work properly. You can see a plastic end cover in the pictures on this page which is along the lines I am talking about - https://www.techsew.com/en/catalog/category/view/s/cutting-skiving-machines/id/566/

That said having good backup and someone you can trust from a supplier is also important.

 

[coltseavers]

On 8/4/2020 at 8:05 PM, Silverd said:

Hello

 

Can anyone explain why a top and bottom feed skiver is better than a bottom feed only?  Can a top and bottom feed skiver do everything that a bottom feed only skiver can do...but more?   If a Leatherworker.net Member is skiving mostly higher temper Herman Oak 3-4oz (1-2mm) leather...can this work be done on a Top and Bottom Feed skiver or should this individual use a bottom feed only skiver.  There is not one sewing machine that does everything...Is this also true for Skiving machines?   Do I need both?   

Your assistance to the questions above will assist me in deciding on which machine to purchase and will ultimately determine the success of my business and the health of my sanity!

 

Many Thanks in advance.

 

Silverd

i still don't understand the difference between top and bottom, can you show me a top and bottom skiver picture? they all look the same to me.