Precision platen?

J

Jason Fry

Knifemaker / Craftsman / Service Provider
Joined
Jun 5, 2008
Messages
3,074
Who out there makes a decent precision platen? Dead flat, high grit finish, radiused edges, hardened steel?

I'm thinking on keeping my regular glass platen for 99% of the work, but looking for something precision for the final grinding and plunge grinding.

Yeah, I could make it myself if I had to....
 
Tim Wright of Sedona AZ makes his own like that. Try him, maybe you can convince him to make you one.
 
Might be a dumb question, but how much real difference would a precision platen make?

What I am thinking is that for making things really flat, the flat platen with a belt has some limitations due to the belts, how flat they can lie, the belt joint, whether they bulge a little up-stream of the work being ground. Radiused edges, well different belts will change that somewhat. Precision might be that the platen has edge radii shaped to a size +/- 0.010", but would you be able to tell from looking a plunge that they were held to that tolerance? One tends to grind plunges over a fairly short and consistent area of a platen, so precision radii all the way around won't make a difference.

Nick Wheeler's demo of a steel block on to which he stuck abrasive paper for dialling in the plunge makes sense, the paper can be made really flat, and you are moving the blade so need a consistent corner over a length.
 
Johnny Ducati is suppose to make a fantastic D2 platen.
 
Here's my thought process. I can grind well enough to make the flats flat, and I have a disk for cleanup if necessary. Precision flatness on a platen is just a luxury. What I'm really after is a set of consistent radiused edges. My current glass platen is less than 3 months old, but the right edge chipped out a little after a bit of use. This inconsistency has been causing problems on my plunges. I fought a dagger for quite a while and still couldn't get it right, because of the limitations of my platen. I did some cleanup on a radiused edge piece of Micarta with the method Nick uses, but I'd rather have a way to get it closer off of the machine. Yeah the belts roll over, every belt is different, etc, but I'm thinking I can work around that if my platen edges are the same.

I'm thinking if I could get or make the platen I want, I could set it up on a different arm, and only pull that arm out for plunges. Keep the precision parts from wearing, and just use the glass for regular grinding.
 
Jason Fry said:
Here's my thought process. I can grind well enough to make the flats flat, and I have a disk for cleanup if necessary. Precision flatness on a platen is just a luxury. What I'm really after is a set of consistent radiused edges. My current glass platen is less than 3 months old, but the right edge chipped out a little after a bit of use. This inconsistency has been causing problems on my plunges. I fought a dagger for quite a while and still couldn't get it right, because of the limitations of my platen. I did some cleanup on a radiused edge piece of Micarta with the method Nick uses, but I'd rather have a way to get it closer off of the machine. Yeah the belts roll over, every belt is different, etc, but I'm thinking I can work around that if my platen edges are the same.

I'm thinking if I could get or make the platen I want, I could set it up on a different arm, and only pull that arm out for plunges. Keep the precision parts from wearing, and just use the glass for regular grinding.
Click to expand...
Drew Riley Drew Riley had a grinding wheel made to get a consistently radiused edge on his glass platen liners. He posted about it in this thread. I am curious what his long term experience is and how the radiused liners held up, so I'm hoping he'll chime in.
 
Hubert S. said:
Drew Riley Drew Riley had a grinding wheel made to get a consistently radiused edge on his glass platen liners. He posted about it in this thread. I am curious what his long term experience is and how the radiused liners held up, so I'm hoping he'll chime in.
Click to expand...
I’m still using the first one I put on my flat platen. It works well, and I do get more consistent plunges than I had been.
I was going to make a handful for other makers, but there didn’t seem to be much interest at the time, so I more/less shelved the project.
 
Check out Kyle Royer IG post dated Jan 7th. He has a pretty good setup going on there. I made one for my KMG and it works great.
 
i have chipped the edge of a pyroceram glass one as well. putting a radius the edges, consider if you do that you might not be able to get a good precise right angle inside corner when profiling. i have found the best way is to color the regular metal platen face with dykem, and run it on the surface grinder attachment with 120 to get rid of the dip, then go up to 400. i do it every year. can anyone quantify how much longer a hardened D2 platen lasts in comparison to a stock platen ?
 
It's rare that I use a tight 90 corner on anything anyway. I don't have a SG yet, but I did make a deal on one this week after shopping for them off and on for 7 years.
 
You must log in or register to reply here.
Back
Top