Rotary Cutter jig thoughts

[Airplanedoc]

I recently went to a Project Linus event in my are to sharpen scissors while blankets for hurricane victims were made.  Many of the women were quilters and ask if I could sharpen rotary cutter blades.    I just browsed the interwebs and found that wolff has a machine to do them but at $1K that is a whole lot of rotary blades to break even. and with the price of them under $5 each it would be hard to charge a whole to to sharpen a blade.   However if a tormek jig were available it could be cost effective.

[Ken S]

I am not exactly certain what size blades you are talking about. I have seen several sizes available by the pack and very reasonably priced. I wonder if it is cost effective to sharpen them.

I am being summoned to play eith my grandson.

Ken

[Airplanedoc]

That's the problem with them, a 5 pack of Olfa blades is $45 at joanns,  or$19 on Amazon.  There are harbor freight ones for a carpet cutter are probably $5.   At the event I was at was a bunch of ladies that can only use the $45 Olfa blades from Joann's, but then they all asked about resharpening them.  So lets say you could get $2 to sharpen a 45mm rotary blade, some online places get $3 you would have to sharpen 3-500 of them to recover your investment in the wolff setup.    If there was a tormek jig that cost the same as the drill bit sharpener, then you are looking at roughly 100-150 units to recover cost at the $2-3 price point.


I did get complements multiple complements on how quiet my sharpening was.    Others had been told not to come back because the noise from the scissor sharpening machine was too much for them to handle.   

[RichColvin]

Carl,

I've sharpened tools like punches using a drill.   I mount the punch in the drill and then spin it whilst holding the edge against the grinding wheel.  (Here's a link to this discussion:  https://forum.tormek.com/index.php?topic=3229.msg18889#msg18889 ).

Could you sharpen the cutting wheel by holding it in a rotating tool like a Dremel or a flex shaft grinder like the Foredom ?

Rich

[AKMike]

If you made an appropriate bushing, it seems like the SVD-186/185 would make quick work of sharpening rotary cutters.

Mike

[Herman Trivilino]

Could you sharpen the cutting wheel by holding it in a rotating tool like a Dremel or a flex shaft grinder like the Foredom ?

I would try that, using perhaps a cordless drill. Since they're so chep to replace there's not much to lose by giving it a try. The cutting edge doesn't slice through stuff to cut it, it's more like a chisel.

[RichColvin]

Well, I put this together:

The exploded pieces are shown below (the flat disks are fender washers) :

I envision sharpening from the vertical position, holding the SVD jig at the Tormek logo, whilst turning it via the handle.

I put a handle on the wheel to aim for an easier way to assure a consistent grind around the wheel.

This SVD-18x jig really does have loads of possibilities.

Now, just gotta convince the wife to let me take apart one of her cutters to try it out ....

Rich

[cbwx34]

Nice work Rich... looks like it'll work well!  Makes me want one... and I don't have any "cutters" to sharpen! 

Just go grab one of the wife's cutters.  Remember, "better to beg forgiveness....." 

Thanks for sharing the pics.

p.s.  I've found "fender washers" to be very handy for some mods... and I'd never even heard of them before.

[RichColvin]

The wife relented and allowed me to sharpen this :

I had to sharpen it in the horizontal position, as I found that when trying to sharpen in the vertical position, the wheel tended to grab the cutting blade and pull it towards the back of the machine.

I made two videos of this in action :

Sharpening the edge on the SG stone :  https://youtu.be/SO4bBOTTI20

Honing the edge on the SJ stone :  https://youtu.be/HTHGrZ5pJb4

The hand wheel I made for the SVD-186 was key to the successful sharpening.  It allowed me to turn the cutter in a consistent manner, not over or under grinding a spot on the continuous surface.  Also, I modified the fender washers by drilling the hole to 8mm.  That allowed them to sit down on the 2nd shoulder of the SVD-186.

I couldn't test the sharpness as I don't have BESS, but it was definitely sharp enough to cut the fabric my wife cuts.  (Oh, and by the way, you have to test it on a cutting board.)

Rich

[RickKrung]

Nice work, Rich. 

I have an SVD-186 its way to me.  I'll replicate most what you have done for mounting the rotary cutter.  One thing I noticed in your videos is there is a very slight up/down movement as you turn the wheel using the handle.  Did you examine the edge to see if there was any indication of differential sharpening due to this action? 

I am wondering about a way to motorize that rotation so as to avoid that up/down movement. I have a slow motion motor controlled by a hobby train controller, that I use for making bamboo fly rods.  I wonder if it couldn't be attached this jig to give uniform rotation. 

Rick

[cbwx34]

The wife relented and allowed me to sharpen this :

....

I couldn't test the sharpness as I don't have BESS, but it was definitely sharp enough to cut the fabric my wife cuts.  (Oh, and by the way, you have to test it on a cutting board.)

Rich

Looks good! (Glad she gave in!)

Cutting what it needs to cut, is often the best test. 

[RichColvin]

One thing I noticed in your videos is there is a very slight up/down movement as you turn the wheel using the handle.  Did you examine the edge to see if there was any indication of differential sharpening due to this action?

Rick,

The cutting wheel is probably not centered on the shaft. Not a huge problem as the jig is not fixed but can move up & down to accommodate.  Or, at least that's what I think. 

When you get a motorized one done, please post pics. 

Rich

[RichColvin]

Looks good! (Glad she gave in!)

Cutting what it needs to cut, is often the best test. 

Thank you.  I agree!

[Airplanedoc]

That looks great,    Apparently I am going to have to beg my machinist friend out of another freebe.

[Trevor Wilson]

Mate, that's a real nice piece of work
Trevor Wilson

I think that if you were able to lock the SDV-186 to the support bar you could you a Foredom Variable speed motor & their flex drive & hand piece it would just be a matter of extending the shaft right through and machining it to 1/8" or 1/4" to suit the collet in the Foredom Handpiece.

I just sharpened a couple for my wife using the Foredom motor and a mandrel I use for Lapidary work, I just used a 1200 grit diamond stone holding it free hand & finished it off with polish on a leather belt. Test cut just fine, wife is happy & I've got weeks worth of brownie points.
Now all has to done is to machine some accurate parts to suit the various size holes in the cutter blades.