Surface Ft / min for belt grinders -

[mikey]

I stand corrected about the name - going off the top of my head and I've been pretty trashed after all the writing I've done.

That is interesting info about the belts. Good to know that Hermes is a quality outfit. Now we need to see if the glue joints hold up beyond, say, a year. These belts are so efficient that I may only go through a single belt to grind all the tools I need and the rest of them will sit so this matters.

I've been very impressed by this belt, regardless of where it comes from. It eats a cobalt bit so fast that I'm thinking about replacing tools that don't really need replacing, just because its so easy now. My grinding time is down to less than three minutes for a cobalt tool and that is just ridiculous. Color me happy!

 

[Alan H.]

Mike, I think they are good belts and am not a surprised that they like cobalt. Hermes is definitely considered good stuff from what I have been told.

I passed a pair to my buddy to see what he thinks. He was impressed that they were Hermes and was familiar with their Ceramit®. He also inspected the joints and pointed out that they are taped and glued.

I am looking forward to the next bit I grind so I can give them a try. Thanks for pointing them out to me back when. I have some other Hermes belts but not this top shelf version.

 

[mikey]

Let us know what you think, Alan. You have 72" of belt and a lot more horsepower than I do. I am betting it will take you all but 2 minutes to profile a tool.

 

[Ken S]

I am resisting the urge to launch into the "studies" again!

My friend and his friends seem to be fans of CubitronII belts from 3M. I once called 3M and they told me that I could run the belts at 7000 FPM with no problem. My grinder will turn up to 5500 but I rarely use it at that speed. I am fearful of being in the line of fire of a 72" belt coming off at 60+ mph and I personally would not want to go much higher than that. I know a knife maker who sustained an unbelievable laceration to his arm from such an incident. This is a very good reason to buy high quality belts with good joints.

I can personally verify that the Cubitrons make shavings on HSS. When I sharpen HSS there is a ball of "steel wool" like material in the quench pot that catches the sparks. It is quite interesting to see this and it also makes one then believe there should be some an optimum SFM. Here's a photo of the shaving notion from a 3M flyer.

View attachment 243343

To your point, I do believe this all has a lot to do with the specifics of the belt in question and unfortunately the info seems a bit hard to come by.

I am resisting the urge to launch into the "studies" again!

My friend and his friends seem to be fans of CubitronII belts from 3M. I once called 3M and they told me that I could run the belts at 7000 FPM with no problem. My grinder will turn up to 5500 but I rarely use it at that speed. I am fearful of being in the line of fire of a 72" belt coming off at 60+ mph and I personally would not want to go much higher than that. I know a knife maker who sustained an unbelievable laceration to his arm from such an incident. This is a very good reason to buy high quality belts with good joints.

I can personally verify that the Cubitrons make shavings on HSS. When I sharpen HSS there is a ball of "steel wool" like material in the quench pot that catches the sparks. It is quite interesting to see this and it also makes one then believe there should be some an optimum SFM. Here's a photo of the shaving notion from a 3M flyer.

View attachment 243343

To your point, I do believe this all has a lot to do with the specifics of the belt in question and unfortunately the info seems a bit hard to come by.

That's interesting Alan. I tried to look this up but there doesn't seem to be much info on it. I'm in the alumina calcining business and had not heard of this product before. I suppose it's possible to fuse alumina into a uniform shape like that. It could either be a fused alumina product or possibly an extruded/fired process using pure alumina or an alumina/zircon blend.
I think it's more accurate to call this a micro milling product than a sanding or grinding product. Cool stuff.

Thanks
Ken

 

[mcdanlj]

Sorry to bring back an old thread, but I read through it looking for this information and didn't see it, so I thought I'd share the results of my further investigation.

I asked Red Label about using their EdgeCore belts on HSS, and they told me:

We recommend any hardened steels for a minimum to be around the 1500 to 2500 SFPM. However those Ceramic belts should perform the best in the 3600-4500 area, but it can also depend on the grit:

Coarser belts around 36 grit -> 4500 SFPM
80 and 120 grit -> 3600 SFPM

 

[mickri]

Vintage machinery has a SFPM calculator for band saws in the tools section. You could use it to calculate the SFPM for a belt sander. I inputted the pulley sizes and wheel size for my 1x42 delta belt sander and got 3160 SFPM.