cobra Bell Skiver, Top and Bottom Feed,

[Silverd]

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

[RockyAussie]

2 hours ago, Silverd said:

Can a top and bottom feed skiver do everything that a bottom feed only skiver can do...but more?

A little bit yes. Bit like a 4 wheel drive compared to a 2 wheel drive. For heavy leathers and rubber and such then yeah go for the top/bottom but for most leather work except perhaps saddlery work I would not have one if you gave it to me. They are a pain and slow to alter the settings and get right but if you are doing a LOT of the same setting and its heavy stuff the go that way. (1to 2mm would be very easy on a bottom feed) If I wanted to skive 4/5mm of firm temper I would do a double pass if it were a wide and thin skive required. At near to the end of this video I did awhile ago you can see me skiving some pretty firm temper leather on a bottom feed but note I am using a roller foot which I use always on anything as can be seen in other skiving videos I have done. I hope to get another vid up soon showing some belt skiving stuff on it as well.

 

Edited August 5, 2020 by RockyAussie
forgot link

[jimi]

Here is a video showing a Nippy (bottom) skiver and some of the different options, I think you would be hard pressed to find something similar showing the options for a top and bottom skiver, but i could be wrong??

 

[Silverd]

Wow!  Fantastic videos.  Bottom feed only machines appear to be capable of everything I would ever use them for.  Ive been in contact with the Nippy folks.  Very difficult to communicate with however.  I did get them to send me a quote for their NP-201 machine which they claim is the export model...But its not clear what the differences are between this and the 210 and 211.  And I absolutely agree that the various presser feet would be essential to the full range of skiving that one could use.  Really great info.  

 

So how does one order some or all of the presser feet from these guys.  From what I can tell they do not have USA representation.

 

Silverd

[Arturomex]

37 minutes ago, Silverd said:

So how does one order some or all of the presser feet from these guys.  From what I can tell they do not have USA representation.

 

 

I don't know if those are Nippy presser feet or not. I've been trying to track these guys down for a while.  On Youtube, the notes attached to the video Jimi posted are in Vietnamese. The website doesn't seem to exist anymore and a search for the trading company that was (is ?) out of Taiwan hasn't brought me any joy. I also would like to get some presser feet from these guys but I think I'm going to go with Campbell-Randall instead just to save headaches.

I'm told that Nippy makes good machines but you certainly don't need to go that route. TechSew, Cowboy and Cobra all offer their version of this clone. I recently got a TechSew SK-4 and I'm very happy with it. While I haven't had to call them about this machine I've talked with their service department about a sewing machine I have and there's a lot to be said for being able to easily communicate with a vendor.

You referenced "higher temper Herman Oak 3-4oz (1-2mm) leather." It might be a good idea to see how well your leather skives with the supplied presser feet. They can change the leather substantially. Brian (RockyAussie) says he does everything with a roller foot. (Check his videos -he shows how he modified the roller foot.) As a novice,  I'm not sure but I think a roller type foot mitigates a lot of the problems caused by using the regular presser feet on, say, tooling leather. Maybe someone with more experience can comment about that.

Regards,

Arturo

[jimi]

19 hours ago, Silverd said:

So how does one order some or all of the presser feet from these guys.  From what I can tell they do not have USA representation.

Maybe try there website page, or as Arturomex said Campbell-Randall sells feet in the USA.  Fratelli Alberti also sells feet for their FAV machines. Fortuna will probably sell them also.

[Silverd]

18 hours ago, Arturomex said:

I don't know if those are Nippy presser feet or not. I've been trying to track these guys down for a while.  On Youtube, the notes attached to the video Jimi posted are in Vietnamese. The website doesn't seem to exist anymore and a search for the trading company that was (is ?) out of Taiwan hasn't brought me any joy. I also would like to get some presser feet from these guys but I think I'm going to go with Campbell-Randall instead just to save headaches.

I'm told that Nippy makes good machines but you certainly don't need to go that route. TechSew, Cowboy and Cobra all offer their version of this clone. I recently got a TechSew SK-4 and I'm very happy with it. While I haven't had to call them about this machine I've talked with their service department about a sewing machine I have and there's a lot to be said for being able to easily communicate with a vendor.

You referenced "higher temper Herman Oak 3-4oz (1-2mm) leather." It might be a good idea to see how well your leather skives with the supplied presser feet. They can change the leather substantially. Brian (RockyAussie) says he does everything with a roller foot. (Check his videos -he shows how he modified the roller foot.) As a novice,  I'm not sure but I think a roller type foot mitigates a lot of the problems caused by using the regular presser feet on, say, tooling leather. Maybe someone with more experience can comment about that.

Regards,

Arturo

Agree the other companies carry good machines but how many of them support with 19 unique presser feet?   I'm actually in communication with Nippy and they appear to have someone at their end who reads and writes English.  They are quoting NP-S1 machine and four standard feet with shipping for about $2600.00 and will provide pricing for additional feet once I provide them with a list.  I'm compiling a list based on the factory video from Jimi.  I also talked with Dave at Cobra in Ontario CA yesterday and asked him to provide a list of the presser feet they can supply.  Obviously buying from a USA based Co is the simplest.  Having a Japanese made OEM machine in the stable is certainly something to consider as well.  I recently purchased a Seiko 50mm cylinder arm sewing machine direct from Seiko and it is a beautifully made piece of equipment.  It replaces a similar clone machine that I never could get to work very well.  Dont know if it was just me or the fact that it was not cloned well...and that is my point.  When you"re having troubles, and you suspect there may be design issues or workmanship issues with your clone, its more difficult to trouble shoot in my opinion.  Basically it comes down to this...You pay for what you get.

 

Silverd

[jimi]

Here is the Fratelli Alberti web page which also has machines and feet etc.....They are the makers of FAV machines which i understand are very well made also.

http://www.fratellialberti.com/lang2/index.html

[Arturomex]

3 hours ago, Silverd said:

Agree the other companies carry good machines but how many of them support with 19 unique presser feet?  

My understanding is that those Nippy feet would fit any comparable machine. If you'd be kind enough to share what Nippy has available, it'd be appreciated.

Wiser people here have advised to get a machine with vacuum. I balked at the price for that and opted not to. If I was doing it again, I'd go for the vacuum.

Regards,

Arturo

Edited August 6, 2020 by Arturomex

[Silverd]

3 hours ago, Arturomex said:

My understanding is that those Nippy feet would fit any comparable machine. If you'd be kind enough to share what Nippy has available, it'd be appreciated.

Wiser people here have advised to get a machine with vacuum. I balked at the price for that and opted not to. If I was doing it again, I'd go for the vacuum.

Regards,

Arturo

The Video above that Jimi posted demonstrates what Nippy can provide as I understand it.  The quote for a NP-S1 machine included three of the feet in the video.  I don't have pricing from them as of yet for additional feet since I have not submitted my RFQ with them.  I'll share once I receive.  Interestingly; I did see a photo of a Consew skiver ( something -4 model) on Craigs list a while back that included at least 15 different presser feet seller was including.  So a full range of feet are apparently available from somebody...  

I've heard that running  a vacuum is helpful as well but I cant identify which machine models will accept a vac.   Also: I have often read that a vac is only needed for production runs but I'm skeptical of anything I here at this point.  Most people can't / don't articulate effectively about technical topics.   

Why do you suggest a vacuum system is helpful?

Silverd

http://www.nippy.jp/  Link to the Nippy site

 

[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.

[xnikolaos]

Heavy duty skivers with upper driven feed roll are machines to skive stiff and heavy materials.

Example FAV ( Fratelli Alberti) CUT, CUM2, CUM3, CUM3K.

Edited December 28, 2023 by xnikolaos

[xnikolaos]

Normal old type universal skivers. Bottom feed only. Good for chrome leathers , not for stiff and heavy.

[TomE]

I've managed to do fairly well skiving 9-10 oz straps with a bottom feed skiver by swapping the feed roller and using a roller foot as described in the post below.  It now takes me ~5 min to swap the feed roller and set up for thin versus thick projects.   Thanks again, @xnikolaos for the FAV AV1-AV2 manual.  It has some useful information that I didn't receive with my used Techsew SK-4. 

 

[Silverd]

Hi

A very good explanation of the two skiving machine types and excellent photos of both.  

I guess a question i have at this point is can a top and bottom feed type skiver be used everywhere a bottom only type feed machine can be used?  

Thank you 

Silverd

 

[xnikolaos]

Silverd. According to skiving machine manufacturers (FAV, Old Sagitta, Old ALPHA) , bottom-feed skiving machines are designed to handle soft and medium hard chrome or vegetable-tanned leathers. Top and bottom feed heavy dutty skiving machines are made for hard leathers, which are usually shoe soles and some leathers of the saddlery. If we make the assumption and divide the leathers into three hardness categories (soft, medium, hard). In my experience, you need both machines for the job. 

I'm not a professional, but I have four old Italian skiving machines and from my experience as an amateur I noticed that I can also skive hard leathers (soles) but in a very long time and at the limits of the strength of the motors and the machine. It simply means I can't.

 Of course, the best answer would be given by a representative of a skiving machine manufacturing company, who supposedly has the information that a simple user does not have.

Edited January 18 by xnikolaos