I'm interested in a surface grinder, so I've been exploring the machinist forums. A common thread is about ripples in the steel after surface grinding. A common cause is a poorly dressed wheel. So now I'm wondering about the modification to grinding belts many of you have done. --- What about "belt bump" ? Doesn't that leave ripples on your blade surface ? They're bad enough just on my flat platten, I can't imagine on a surface grinder.
Hello Dennis,
It really depends on what you are trying to do with the grinding operation. If you are looking for precision grinding to very tight dimensions with a decent finish, a surface grinder was designed to specifically do that. I personally am not a fan of the belt conversions for surface grinders as it is sort of a modification that knifemakers use to do a job that it wasn’t really designed to do, i.e. heavy metal removal, cleanup and shaping. Mills, heavy cutters and Blanchard grinders are actually the tool that would be best int these situations.
If going for a good finish on a properly equipped surface grinder, yes, the dressing is where it is at. I can hog off more metal with a rougher finish, or I can come off the grinder with close to a 400X satin simply by how I dress the stone. Of course, you have to have good stone as well.
A rubber wheel will have give (durometer is a factor) that will not give you the same accuracy as a well-dressed hard wheel, but you may be able to control the chatter and waves with spindle and feed speed.
Thanks Kevin. So since I'm wanting to go into making slip joints, I guess it's 'keep the stone". But if I want to hog off some damascus for the blades, forge thin ?
Re-read your post, Kevin. Same stone can hog off steel, just a rougher finish.
Oh yes, for folder work, I personally would want to work with a stone. For flattening and descaling, I guess the belt would work. I think that this is where those "surface grinding" attachments for you belt grinder would be a good way to go while maintaining your precision with an actual surface grinder.
There are many different stones, I found a deal on a Norton SG wheel that is one of the better stones for surface grinders but then I have a very large grinder, a smaller diameter wheel may be less pricey than mine.
