Dumb question of the day - What do you use your rotary platen for?

Signalprick

Signalprick

Jason Ritchie
Gold Member
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Apr 3, 2009
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First off I ask this question from the standpoint of a slip joint folder maker. I have a rotary platen and the only use I've found so far for it is for doing swedge grinds. Honestly my swedges have improved greatly since so if that's all I ever get out of it so be it but I'm curious if there might be some unlocked potential I am unaware of. So let's hear it, what are you using your rotary platens for in the knifemaking process?
 
Honestly I need to find more uses for mine too. I've used it finish grinding plungeless knives but anytime there's a plunge I find it too soft to get into the plunge but I know people do it so I should experiment more with the platen backed section. It was something I thought would improve my belt finish but so far haven't realized that.
 
you know what's dumb, is I don't know what a rotary platen is
 
ah that, those look cool. I think I'd use one if I had one, sometimes but for certain things. I do tend to pull the ole reach around on my platen though and it doesn't look like a good idea to stick anything anywhere near inside that setup when it's running
 
Yeah, its main purpose is convex bevels on a knife. It basically lets you control the amount of "slack" you would get in a slack belt for convexing things. I would flat grind it and then use the rotary platen and a file guide to keep the plunges crisp and clean. They are usually adjustable slightly to alter the amount of give/support the rubber belt has behind the sanding belt. They are also nice to sand handles, round spines, etc, but pretty pricey. I just use S2-32 hard Felt or F3 felt on a metal platen to get the same effect. Much cheaper!
 
I removed the platen to get that convex bevel shape on the machete I'm working on- which seems fine for y weight belts, but for lighter weights it's probably not a great idea
 
SBuzek said:
Nothing better for shaping and blending bolsters.
Rounding and shaping G10 and micarta covers.
Click to expand...
I've been using my 12" contact wheel for initial shaping of my bolsters. I'll give the next bolster build a try this way. Makes total sense! Do you run an X or J weight belt when doing this? Thanks for the comment and idea.
 
Signalprick said:
I've been using my 12" contact wheel for initial shaping of my bolsters. I'll give the next bolster build a try this way. Makes total sense! Do you run an X or J weight belt when doing this? Thanks for the comment and idea.
Click to expand...
I also rough shape on a 10" wheel then switch to j weights on the rotary
 
Taz said:
Yeah, its main purpose is convex bevels on a knife. It basically lets you control the amount of "slack" you would get in a slack belt for convexing things. I would flat grind it and then use the rotary platen and a file guide to keep the plunges crisp and clean. They are usually adjustable slightly to alter the amount of give/support the rubber belt has behind the sanding belt. They are also nice to sand handles, round spines, etc, but pretty pricey. I just use S2-32 hard Felt or F3 felt on a metal platen to get the same effect. Much cheaper!
Click to expand...
Wow! I've been looking for an alternative to spending the bucks on a rotary platen. Where did you get the felt? Just epoxy it on a flat platen?
- Thanks ! Update: I found the link for the felt. But still, what kind of adhesive did you use to attach it to the platen?
 
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I just use double sided carpet tape to stick it to a platen. I took some 2x2.5" 1/4" thick angle iron to make up spare platens for my AmeriBrade Combo Platen assembly. One is set up to help square hidden tang shoulders and rough hogging/profiling, one is S2-32 felt, one is S3 felt. 1/4" F3 (30-40 Durometer Shore A) from Amazon, 1/4" S2-32 from McMaster Carr (80 durometer Shore A). I tried some 3/8" thick F5 (20-30 Duro Shore A), but it is too soft and doesn't put much pressure on the belt until you lean into it a lot. The S2-20 (50 Duro Shore A) or S2-24 (55 Duro Shore A) from McMaster may be worth the look at instead of the F3 felt.

I just replaced the F3 felt on my platen and will do the S2-32 this week. I did several kitchen and camp knives with them. I did some profiling on my F3 one and it put a nice groove in it, which is why I changed it out.

The F5 has the adhesive on the back, but always seemed to come off, so I still used the double sided tape on it.

Some people use leather for a soft platen, some use a piece of scotchbrite between the leather and metal platen for some give. The leather may keep crisper plunge lines since the felt tends to roll at the edges more.
 
a machete I'm working on has a fully convexed bevel, and for that I removed the platen and used y weight belts. Probably not the safest option but it felt safe enough and worked as well as I could've hoped
 
Troop said:
Wow! I've been looking for an alternative to spending the bucks on a rotary platen. Where did you get the felt? Just epoxy it on a flat platen?
- Thanks ! Update: I found the link for the felt. But still, what kind of adhesive did you use to attach it to the platen?
Click to expand...
I used JB Weld to attach the leather to my soft platen, and it works great.
 
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