Why Disk Sander ??

[Cushing H.]

Is there anything / something that you can do with a DISK sander that you can not reasonably do with a grinder? I definitely have need to flatten/square handle material ... and am thinking I can do that with my grinder (properly set up and squared). Am I misguided - and need to add another piece of equipment?

 

[Drew Riley]

Is there anything / something that you can do with a rotary sander that you can not reasonably do with a grinder? I definitely have need to flatten/square handle material ... and am thinking I can do that with my grinder (properly set up and squared). Am I misguided - and need to add another piece of equipment?

Insides of rings or really tight radii I suppose. More tools are never a bad thing.

 

[Cushing H.]

Im sorry ... i mean a disk sander

 

[REK Knives]

I've found that the disk dander gets stuff a little flatter than the belt grinder but if you want it perfectly flat then you need to use the surface grinder or mill.

 

[weo]

Good afternoon, Cush. I think the most basic answer to your question is, time.
Gets things flat fast.

 

[Cushing H.]

Got it. Thanks.

 

[coldsteelburns]

If I'm trying to flatten something, I'll take it to the disc and then take a few pass on a surface plate to make sure everything's good. It's hard to beat if you're wanting to get your bevels nice and flat before hand sanding, and it also works great for flattening and squaring up your ricasso, although that can also be done on a surface grinder. It's a tool that you can get by without, but there are many times where it really comes in handy.

For what it's worth, Kyle Royer mentioned that just got one within that last year, and while he already had a nice mill and a surface grinder, he mentioned just how much he appreciated having it and that he enjoyed using it.

Here's a good video by Nick demonstrating how useful it is for flattening the bevels in order to make hand finishing much quicker and easier, especially on a large blade:

~Paul
My Youtube Channel
... (It's been a few years since my last upload)

 

[Jason Volkert]

From my experience ( I have a disc and 2x72 both with VFD) a 2x72 is almost impossible to get things truly flat. Disc sander gets things real flat. The sand paper is glued to a solid flat surface.

 

[HSC ///]

Another nice thing about a 9 inch disc sander is that they are relatively inexpensive compared to the 2 x 72 belt grinder

I think the disc sander is lot of value for the money

 

[Drew Riley]

I built a 9" disc sander a while back, and it gets quite a bit of use. FYI, the late Tim Hancock had a video or two out there showing his grinding practices, which incorporated a disc sander pretty heavily.

 

[lanternnate]

The belt bunches up at the edge of the work piece, so that will impact the grind on that corner. You also are only getting 2” wide chunks at a time along a longer blade making the chance of getting waves higher by tilting or changing pressure. The disc has paper glued to it so it doesn’t bunch up and gives you a bigger surface to lay the work against for more stability. Abrasives to go up into high high grits is also cheaper because you can just use cut down 9x11 sheets rather than needing lots of belts.

 

[Cushing H.]

The belt bunches up at the edge of the work piece, so that will impact the grind on that corner. You also are only getting 2” wide chunks at a time along a longer blade making the chance of getting waves higher by tilting or changing pressure. The disc has paper glued to it so it doesn’t bunch up and gives you a bigger surface to lay the work against for more stability. Abrasives to go up into high high grits is also cheaper because you can just use cut down 9x11 sheets rather than needing lots of belts.

Hmmm. I guess i was only thinking about the disk sander in terms of flattening and squaring handle stock. Ill have to look at some of those videos on using them to grind blades.

i have also been “hooked” by the VFD on my grinder - ifi geta disk sander no doubt i would want variable speed ... but no doubt the 220v motor will drive up the price :-(

 

[scott kozub]

Ive never tried it but I have heard some of the users here will also use a disk sander on full flat grinds.

I bought one a couple months ago used because it came up for a steal. I like it for flat and the 6" belt portion is great for scales.

 

[Cushing H.]

Ive never tried it but I have heard some of the users here will also use a disk sander on full flat grinds.

I bought one a couple months ago used because it came up for a steal. I like it for flat and the 6" belt portion is great for scales.

But those combo units dont have dust collection?

 

[john april]

i am a naturally skeptical kind of guy. most people say the disc is what they use for flattening. towards the center of the disk, the paper turns more slowly and with less surface area passing per minute than the outside edge. there will always be more removal toward the outer edge. how could something get flat on that ? just curious

 

[Randy3000]

i am a naturally skeptical kind of guy. most people say the disc is what they use for flattening. towards the center of the disk, the paper turns more slowly and with less surface area passing per minute than the outside edge. there will always be more removal toward the outer edge. how could something get flat on that ? just curious

You are 100% correct. You also need to consider hand pressure. It makes a big difference! If you want something flat and even thickness, you better have calipers on hand and adjust position and hand pressure a lot. Just laying the stock on the disk and wiggling it a bit isn't enough if you want it to be flat and even thickness, you can easily get 0.030" off or more edge-to-edge.

 

[Cushing H.]

You are 100% correct. You also need to consider hand pressure. It makes a big difference! If you want something flat and even thickness, you better have calipers on hand and adjust position and hand pressure a lot. Just laying the stock on the disk and wiggling it a bit isn't enough if you want it to be flat and even thickness, you can easily get 0.030" off or more edge-to-edge.

I ran in to that trying to flatten handle stock on my grinder. Despite using a caliper and adjusting location and pressure, it was NOT easy to get flat on both sides, and uniform thickness across the width. Is the only “easy” answer a surface grinder? (Which means more $$$)...

 

[Josh Rider]

John I can’t speak for what everyone else is doing, but I make passes just like I do on a belt grinder from plunge to tip and back.
You don’t just leave it in one place.

i am a naturally skeptical kind of guy. most people say the disc is what they use for flattening. towards the center of the disk, the paper turns more slowly and with less surface area passing per minute than the outside edge. there will always be more removal toward the outer edge. how could something get flat on that ? just curious

 

[Jason Fry]

Couple of things that haven't been said yet. They make "flat" and "one degree" disks. I have a flat one for... flattening, on an air conditioner motor with a bump switch. I have the one degree hooked up onto my VFD, so it's reversible and speed controlled. I use it for the blade grinding functions as mentioned in this thread. Both have their place, but I can say that I use the flat one every single knife, and the variable reversible one is a belt holder most of the time. On the other hand, the reversible is THE tool for the job, and gets used on the big bowies and sometimes the kitchen knives as well.

 

[AVigil]

i am a naturally skeptical kind of guy. most people say the disc is what they use for flattening. towards the center of the disk, the paper turns more slowly and with less surface area passing per minute than the outside edge. there will always be more removal toward the outer edge. how could something get flat on that ? just curious

That is why you flip from end to end, to mix it up, with even pressure.