building a combo belt\disk grinder - good idea?

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Berser

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May 20, 2023
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Hi everyone, new guy here

I'm a new knife maker, made a few nice gifts for friends and i want to level up my shop. (which is very small... an anvil, a small forge and a bench grinder...)

I was planning on building a 2x72 belt grinder, even bought the plans from housemade, but then i saw some YT videos about the use of a disk grinder in flattening blades after the belt grind.

So, i was thinking about building a belt grinder, with an attachment to the drive wheel to turn it into a disk grinder.

i'm planning on using a 2HP 3000RPM 3PH motor with VFD.

What are your thoughts and tips in the matter?

Also, i am considering building a simpler belt grinder, with only two wheels (drive and tracking) that will take less space then the amazing monster in housemade's plans.

I am not a big fan of hollow grinding so i don't think the ability to use a wheel plate is very useful - also will save some money on the wheels (which seems really expensive... why is that?)

So... share any thoughts... Thanks !!!
 
There's a reason the 3 wheel version of the 2X72 is about 99% of the grinders built - they just work better. You're only saving 1 wheel - 2 wheels if using a platen.

I take it you are talking about mounting a disk plate to the drive wheel? If you can rig something to get the disk attached to the drive wheel I don't see why it wouldn't work pretty good for hobby use. Both the 2X72 and disk grinder really NEED a VFD for variable speed.
 
Personally, I'd still stick with a tool arm style of grinder if only for the ability to add a small wheel attachment more easily. I know not everybody uses small wheels, but they sure do come in handy for the work I typically do. Then there are things like dedicated slack belt and rotary style platens, different styles of flat platens, and a rubber contact wheel comes in handy for more than just hollow grinding. To each their own though.

As for pulling double duty with a disk grinder attached to your drive wheel, I've seen it done, and it seems to work. Personally I prefer a dedicated disk grinder. They definitely a lot simpler and cheaper to build than a 2x72, though I get the need/desire to try to save some money.
 
Make or buy a standard tool arm grinder. Make a separate disc grinder. Look at the True Grit and Beaumont disc grinders for ideas. You want VFD on both machines. One VFD can run both. A 1.5HP to 2HP 3Ph motor on the belt grinder and 3/4HP 3Ph on the disc is a good size.
 
Stacy E. Apelt - Bladesmith said:
Make or buy a standard tool arm grinder. Make a separate disc grinder. Look at the True Grit and Beaumont disc grinders for ideas. You want VFD on both machines. One VFD can run both. A 1.5HP to 2HP 3Ph motor on the belt grinder and 3/4HP 3Ph on the disc is a good size.
Click to expand...
Why invest the two separate motors and the added workspace?
 
One reason is that teh disc grinder will be situated at a position you can't alter. A dedicated grinder can be placed on the edge or end of the bench. Also, combo units just don't work as well as dedicated units.

For a hobbyist, a combo machine may work OK. If you want to get into knifemaking more seriously, you will need a better setup with separate belt and disc grinders.

My advice is always to buy or build the best machine you can. It will last longer and probably do a better job than something with compromises. (It will also be much easier to sell if you get out of the hobby or buy/build bigger equipment later on)

You can buy the disc grinder table assembly as a kit from Beaumont or True-grit and add your own motor/VFD. Same for a good grinder. The Reeder basic kit is really a bargain for a top-notch machine. For around $2K you could put together a great belt grinder and a great disc grinder running off one VFD.


While exaggerated in quality, I think you can see the difference in these photos:
6Y945_AS02

71CPGtljj9L._AC_SL1500_.jpg



products-IMG_0610%27_1280w.jpg
 
BTW, Welcome to Shop Talk.
Filling out your profile with your location and some info about you will allow us to give better suggestions and advice as well as let other makers in your area offer help and supplies. You might get free motor or even someone's old disc grinder.
 
Something to think about having separate machines......

I have a Pheer 2x72. Love it and I recommend it.

I also am building a disk grinder.

I hand grind/sharpen my knives on bench stones.
I'm going to mount my disk grinder horizontally, so my body dynamics stay the same. Idk if that could be done on a combo?
 
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I can't find the pic now but I've seen a disc sander attachment for a 2x72 grinder.
It was as if you were using the side of a contact wheel as the disc sander.
The big plus is that you can use the VSD of your grinder.
 
I just finished my housemade 2x72 grinder this week and absolutely love it. Couple things I would tweak on the next one and different ways to do the tru-tilt table too but that's besides the point.

Black fox makes a 9" disk grinder tooling arm if you absolutely want just one grinder to do everything. Only thing is you have to stand to the side of your grinder and it may be inconvenient if you don't have the extra space to that side.

SALES LINK REMOVED. - Please do not post sales links to non-BF sites.
 
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Makerinarms,

Welcome to Bladeforums and Shop Talk. I didn't want my edit of your post to seem unfriendly and wanted to explain.

Please do not post sales links to non- Bladeforums sites. This is a violation of Spark's rules. The dealer members on BF pay for the privilege to advertise here and posting sales pages and ads for non-member sites is basically free advertising. You can give the name of the seller and talk about their product. You can post a photo of the product, just not a sales link page. You can't post prices.

It is not a big deal as you are new and unaware of this rule.

Stacy - Moderator
 
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