Belt thinning

[Bensbites]

I commented on this thread :

https://www.chefknivestogoforums.com/vi ... 80#p105980

About using my 1x30 to thin blades. Since I am really enjoying this, I know my next big step this year will be bladesmithing. I am not sure what direction to start... that’s another topic of conversation.

There are two grinders I have used for thinning blades, both were purchased for different reasons.

RIKON Power Tools 50-151 Belt with 5" Disc Sander, 1" x 30", Blue

And

Grizzly Industrial T10010ANV - 10" Wet Grinder Kit - Anniversary Edition



If I did it again I would consider this 1x30 Variable speed. The variable speed would be helpful for blades, not wood.
RIKON 1in. x 30in. Belt / 6in. Disc Sander


As far as belts, I generally buy from red label abrasives and have been very happy. I am working my way through cheaper belts I had in stock, but will replace them with red label belts.

I have taken a few Richmond knives and Dao knives to thin belts teaching myself along the way. In fact my next Instagram giveaway will be the most recently thinned knife. I took this to what I think would be a laser, and it still has some food release. Here’s some photos and videos.

The starting point


Various results.





URL=https://www.instagram.com/p/B_pzSBaD-BG/][/URL]

[Carlo]

Thank you Ben!

Asking for your thoughts is very much speculative at the moment but I’m hoping to to move “back home” from the city soon and as someone who virtually grew up at workbenches but has been in a tiny apartment for years I can feel my interest brewing.

I have a single project knife at the moment and after quite a few hours it has been transformed. It’s one of the more satisfying things I’ve done lately.

I had no idea what kind of 1x30” machines people meant (Harbor Freight vs high end) but those machines seem reasonable. Had you considered a 1x42”?

[Bensbites]

Thank you Ben!

Asking for your thoughts is very much speculative at the moment but I’m hoping to to move “back home” from the city soon and as someone who virtually grew up at workbenches but has been in a tiny apartment for years I can feel my interest brewing.

I have a single project knife at the moment and after quite a few hours it has been transformed. It’s one of the more satisfying things I’ve done lately.

I had no idea what kind of 1x30” machines people meant (Harbor Freight vs high end) but those machines seem reasonable. Had you considered a 1x42”?

I started with a 1 x 30 because it was all I needed for shaping western wood handles. at this point, looking at what most established makers, even high end hobbyists use, is 2 x 72 with variable speed. lets just ball park it to 10 x the cost. even the 2 x 48 machines look like they will have a relatively quick payback on the abrasive costs over a 1 x 30.

[sbuckel]

What would you recommend between the Grizzly and the Rikon variable speed belt grinder? I was considering getting that same variable speed rikon, but it seems like the grizzly might be a better option. When I first started sharpening my own knives I had no idea about the need to thin them, so I have a few older knives that need some serious thinning done to them. I’ve been thinking about picking up one of those things two after checking out this thread so I can fix them up and either put them back or work or hook my brothers up with some decent knives to use at home.

[Bensbites]

What would you recommend between the Grizzly and the Rikon variable speed belt grinder? I was considering getting that same variable speed rikon, but it seems like the grizzly might be a better option. When I first started sharpening my own knives I had no idea about the need to thin them, so I have a few older knives that need some serious thinning done to them. I’ve been thinking about picking up one of those things two after checking out this thread so I can fix them up and either put them back or work or hook my brothers up with some decent knives to use at home.

I have a rikon single speed, I forget why I chose that over the competition. My purchase was intended for western rehandles and needed dust collection. That variable will not cone into play with your needs.

[Wjhunt]

What 2x72 are you planning to purchase Ben? I’ve looked into them for a while but I can’t seem to make the commitment. It seems like another rabbit hole. Step pulley vs. vfd, contact wheels, cooled platen, etc. I’m a big fan of quality tools (powermatic,festool) . KMG and Burr King look like good manufacturers but I don’t see myself purchasing a MOAG. Just curious about what you are planning to purchase for knife making.

[Bensbites]

What 2x72 are you planning to purchase Ben? I’ve looked into them for a while but I can’t seem to make the commitment. It seems like another rabbit hole. Step pulley vs. vfd, contact wheels, cooled platen, etc. I’m a big fan of quality tools (powermatic,festool) . KMG and Burr King look like good manufacturers but I don’t see myself purchasing a MOAG. Just curious about what you are planning to purchase for knife making.

Great questions. I have talked to other makers here, other forums and Facebook groups as well.
-Build vs buy, debate one. My maker skills could build me a good one, but if I think about the limited shop time I have and How valuable that time is when making handles (and maybe blades), I think I will buy. Housework has an interesting build kit.
Features. Vfd- seems worth it. Tilting frame, questionable. Misting- prob not. I think I want a table that wraps around the platen... that might be the most limiting.
I really haven’t heard anything bad about any brand. The brands I have been recommended. OBM, ameribrade, coats, northridge, and polarbear forge kit.

I am both saving $$ and figuring out how to rearrange the shop to accommodate this new beast. For now my 1x30 will have to work.

[Jakeonthekob]

Looks awesome! I would definitely consider a good 3 phase motor that has at least 1.5hp and VFD. If you can run 220V then 2-3 hp is nice. I got a Reeder grinder that's pretty decent and comes with a horizontal tilt feature but I don't use it. To save some money, you may consider buying a frame with all the wheels and attachments you want, then buy the motor and VFD separately then wire it up yourself. Best of luck and looking forward to seeing what you get!

[Jeff B]

Looks awesome! I would definitely consider a good 3 phase motor that has at least 1.5hp and VFD. If you can run 220V then 2-3 hp is nice. I got a Reeder grinder that's pretty decent and comes with a horizontal tilt feature but I don't use it. To save some money, you may consider buying a frame with all the wheels and attachments you want, then buy the motor and VFD separately then wire it up yourself. Best of luck and looking forward to seeing what you get!

Most buildings aren't wired for three phase unless it's a commercial space and even then it's not a given.

[Jakeonthekob]

Does the building need 3 phase? I thought it refers to the motor strictly so that it can be used with a VFD. I have a 2hp 3 phase motor with kabac VFD that I'm running using a quick systems 220V converter no problems.

[Bensbites]

Does the building need 3 phase? I thought it refers to the motor strictly so that it can be used with a VFD. I have a 2hp 3 phase motor with kabac VFD that I'm running using a quick systems 220V converter no problems.

my understanding is that VFDs run off three phase motors. The VFD takes household voltage an converts it to run the three phase, running a three phase motor without a VFD would require special wiring. I do believe my boredom rabbit hole will be filled by researching to firm up my knowledge tonight.

[ken123]

Perhaps a bit late on this older post.

You do need a 3 phase motor for vfd work. You can get linear motors but they are pricey and not ideal.

You can use 2 phase 115 or 220 volts in the [residential] house. Just be aware that many vfd units will convert 2 phase to 3 phase BUT this requires more amperage. So off of a 2 phase 220 volt line of 30 amps you could run a single phase 5 hp motor, but using a vfd with a 3 phase converter 3 hp is pretty much a maximum.

3 phase is essentially 3 sine waves interposed, yielding essentially a rectified signal, hence the additional amount of amperage required.

Ken

[Bensbites]

Perhaps a bit late on this older post.

You do need a 3 phase motor for vfd work. You can get linear motors but they are pricey and not ideal.

You can use 2 phase 115 or 220 volts in the [residential] house. Just be aware that many vfd units will convert 2 phase to 3 phase BUT this requires more amperage. So off of a 2 phase 220 volt line of 30 amps you could run a single phase 5 hp motor, but using a vfd with a 3 phase converter 3 hp is pretty much a maximum.

3 phase is essentially 3 sine waves interposed, yielding essentially a rectified signal, hence the additional amount of amperage required.

Ken

Thanks Ken, I have gone way too far down this rabbit hole. The grinder parts are on order. I will be building the 2x72 revolution from HouseMade.us.

[ken123]

Excellent, Ben.
If I can help, let me know or better yet show it off when you get it put together.

Ken

[Wjhunt]

Good luck with your grinder build.
I’m curious about the motor after reading the last few posts. How many hp do you need for a belt grinder? My table saw has a 3 hp motor and it does not bog down at all. I’ve broken the belts before and I have been thankful for standing out of the way (wood flying back), but I can’t remember bogging the motor down.

[Bensbites]

Good luck with your grinder build.
I’m curious about the motor after reading the last few posts. How many hp do you need for a belt grinder? My table saw has a 3 hp motor and it does not bog down at all. I’ve broken the belts before and I have been thankful for standing out of the way (wood flying back), but I can’t remember bogging the motor down.

That is the million dollar question. I have a 1x30 with a 1/4 or 1/2 HP and a 4 x 24 rigid edge sander in the same HP range. I can bog those down when sanding wood or metal rather easily. That’s the experience I can speak to.

Next up internet research. Most say 1.5-2 hp work well, 1 Hp is a little weak. I am assuming this is for bulk steel removal prior to heat treat when you don’t have the worry about over heating the edge. Ceramic belts also require more force to break the ceramic and regenerate the sharp abrasive vs just glazing over. At least in the US you can get a 2 hp motor on a VFD and wire it to a 110 outlet (Non GFI) for 1.5 HP. The same setup can be wired for 220 and get you 2 HP. This is perfect for me, I plan on starting out with the 110 based on where I want this is my workshop. The only 220 outlet is for the 3 HP sawstop, right now I don’t want the wet grinder near that.

[ken123]

I have a burr king with 1.5 hp on a 115 volt 20 amp line and a Coote grinder with a 3 hp on a 220 volt 30 amp line. The reason for 3 hp isnt for power at full rpm. Its for full power at low rpm. Even if I stall the belt from hand pressure the motor keeps going. For that much force the burr king will blow a fuse or power strip.
Ken

[ken123]

Note that single bevel knives are harder to grind - you are grinding more surface area. This also applies to full width convex grinds where you are resurfacing a whole blade surface.

Also note that pulley belts take a lot more to damage than sanding / grinding belts. Havent done that yet. Sanding belt 'face slaps' aren't that bad unless it's a 24 grit belt Kickbacks on a power saw - that can be very bad!

---
Ken

[taz575]

I miss my KMG Variable speed

But one thing I noticed with it was that I used it at very slow speed, 10-20% speed like 80% of the time. The only time I went up to around 50% was hogging metal or wood/handle material off with very coarse belts. I would almost opt for a single speed motor and get a pulley set up so I could adjust the speed with pulleys since I usually only used 2 speeds anyway. A 1725 RPM motor with a 2" pulley on each would give you 1725 RPM, which should be plenty fast for most rough work and then working with a pulley to go up to 4" would give you around 800 RPM. I am using a small wheel home made grinder with a 1/2 HP 1725 RPM and a 2" and 4" pulley and am running around 900 rpm or so and using small contact wheels 1/2", 1" and 2" and haven't killed any bearings yet. I usually go up to a 320 or 400 grit belt and hand sand from there. Since it's a slack belt/small wheel setup, I haven't done much with blade grinding yet, but for handles, its sweet.

This looks very interesting, especially when used with a 1725 RPM motor! Would knock the speed down to 25% w/o any torque loss.
https://originblademaker.com/product/2- ... -5x8-bore/

[Bensbites]

Since this thread started I have started building my 2x72 based on the plans and kit from HouseMade.Us. I am trying a lesser known brand of motor and VFD to save some $$. It’s a risk that I am willing to take and will not cry too much later if I have to replace them. The frame is a beefy beast, and I am super excited about the 11 inch platen. Give me a couple weeks and you will see it built. Until then, I will work on my 1x30 to bang out a few blades.