Crowd Dev? New Platen design

So, here's one of my concerns. I threw the current revision into my new grinder design and even butting up the platen side to the point of interfering with the grinder, I still end up with a 73"+ belt loop. Now that's easy enough for me to modify as I've not yet built this grinder and it's a little long in the front anyway, but are other people going to have this issue with the conglomeration of various tracking wheel heights and various sized drive wheels and distance from drive wheel to front face of tool arm sockets?

upload_2018-1-7_12-10-4.png
 
Haha, I've always had the opposite problem since I run 50x2000 belts. I need to make sure my tool arms are long enough.

You should have seen the length of my work rest tooling arm for my small wheels. It was looooong, before I got a new small wheel setup which has an attached work rest.

Cool grinder concept by the way! I like the ratchet mechanism. :thumbsup:
 
Thanks. I can't take full credit. It's got features from a number of different grinders. Basically I took everything I liked about 3 different machines and put them together. Mainly to get a ratcheting tension arm, motor wheel tracking, and tool arm quick clamping. It was more modification than I thought to get into the loop range, but that's OK. Easier to fix in the model than in real life. I didn't put nearly this much thought into my original builds, mostly because I didn't have much grinding experience to know what I really wanted.

This thing however should be pretty trick when all said and done.

upload_2018-1-7_15-34-8.png
 
Maybe I missed something in all the previous pages ( which I haven't read through yet) but why is there so much space to move the platen forward and back? It only needs to move maybe 1" to adjust things or go back to run the belt slack. Seems like you could easily move the two wheels back 2" and gain a lot of belt length.

I do find your ratchet tension adjustment cleaver. Simple and functional.
 
It's solely to increase clearance on the left side of the platen. You only need about 2.5" of travel to use any combination of radius platen, chiller, no chiller and flat platen.
 
Love this thread, great work Brock and Kuraki! Love that extra clearance and the locking lever mechanism.
 
Personally I'd rather work around the left side limitation than have that massive of a platten. For some grinders it would be fine, but for those of us who own (or just ordered) a square wheel/bee style grinder, it might pose a problem.

But if that's just a me thing, it would be easy enough to buy just the chiller and radius platten unit and make a different unit to mount it and the wheels on.
 
Geoff Flato said:
Personally I'd rather work around the left side limitation than have that massive of a platten. For some grinders it would be fine, but for those of us who own (or just ordered) a square wheel/bee style grinder, it might pose a problem.

But if that's just a me thing, it would be easy enough to buy just the chiller and radius platten unit and make a different unit to mount it and the wheels on.
Click to expand...


You are right of course. The left side clearance thing isn't the best thing this design has to offer. Quickly and easily changing out platens without changing the whole tool arm assembly is the core benefit.
That amounts to a drilled and mounted clamp block, some rods, and a platen mount.
Likely that bit could be added to some existing platen frames.
 
Hey John. On the 3 inch wheel mount, does it make sense to make either two holes, or a slot. Just so it could accommodate a 2 or a 3 inch wheel?
 
I am going to come out with my dumb question. What is better with this platen design than others? Why is the face curved?
 
Tin.Man said:
Not to derail, anyone know if it’s possible to rock a radius platen without a chiller? I understand the heat build up is pretty high, curious if graphite might help?
Click to expand...

I recently added a flat platen to my Beaumont rotary platen. The heat generated to the platen by the ribbed rubber belt was way more intense than I anticipated, after grinding one side of about a 3.5" blade I misted the back of the platen with water and it sizzled and steamed. I applied a piece of the graphite backing to the platen so the rubber belt would not run against the metal platen and it reduced the heat to where I could touch the back of the platen after grinding the other side of the blade. Will have to grind a few more to see how well it holds up with the friction over time.
 
The barefoot boy said:
I am going to come out with my dumb question. What is better with this platen design than others? Why is the face curved?
Click to expand...

There are many styles of Japanese kitchen knives that have a slight concave surface by design. This is why most makers want this platen. It mimics a large grinding stone like the traditional Japanese smiths have used for many years.
It can also be aplicable to hunting knives. It will produce shallow "hollow grinds."
 
Brock Cutlery said:
Hey John. On the 3 inch wheel mount, does it make sense to make either two holes, or a slot. Just so it could accommodate a 2 or a 3 inch wheel?
Click to expand...

If I made the arms the same length, it would have to be a slot since the 1/2-13 holes would only be 1/2" apart, and then I would worry about stability. However it's easy enough to have a platen side that's 2x2 length arms, and another that's 2x3, if people wanted both.

Alan Davis Knives said:
I recently added a flat platen to my Beaumont rotary platen. The heat generated to the platen by the ribbed rubber belt was way more intense than I anticipated, after grinding one side of about a 3.5" blade I misted the back of the platen with water and it sizzled and steamed. I applied a piece of the graphite backing to the platen so the rubber belt would not run against the metal platen and it reduced the heat to where I could touch the back of the platen after grinding the other side of the blade. Will have to grind a few more to see how well it holds up with the friction over time.
Click to expand...

Did you have ceramic on it? Or just steel?

Geoff Flato said:
Personally I'd rather work around the left side limitation than have that massive of a platten. For some grinders it would be fine, but for those of us who own (or just ordered) a square wheel/bee style grinder, it might pose a problem.

But if that's just a me thing, it would be easy enough to buy just the chiller and radius platten unit and make a different unit to mount it and the wheels on.
Click to expand...

I don't understand the popularity of those grinders. They seem extremely limited, but I've only seen pictures. But because they seem so limited, I think the platen mounting block and 2 shaft system would be a huge upgrade, allowing you to swap platen types on a whim. And easy enough to adapt.
 
IMG_1539.JPG IMG_1540.JPG
Just steel. I do not like the ceramic, my body seems to attract a high amount of static electricity.
 
Last edited:
Putting a plate behind a rotary platen pretty much destroys the reason behind the flexing belt. Why not just grind on a standard flat platen?
 
Brock Cutlery said:
Putting a plate behind a rotary platen pretty much destroys the reason behind the flexing belt. Why not just grind on a standard flat platen?
Click to expand...

There are still three sides to use the rubber belt with out the platen which I do on every knife for handles. The platen behind the belt eliminates the notorious belt bump of a metal platen completely when doing a flat grind and speeds up flat grinds significantly. Google the Moen platen and read the reviews.
 
kuraki said:
If I made the arms the same length, it would have to be a slot since the 1/2-13 holes would only be 1/2" apart, and then I would worry about stability. However it's easy enough to have a platen side that's 2x2 length arms, and another that's 2x3, if people wanted both.



Did you have ceramic on it? Or just steel?



I don't understand the popularity of those grinders. They seem extremely limited, but I've only seen pictures. But because they seem so limited, I think the platen mounting block and 2 shaft system would be a huge upgrade, allowing you to swap platen types on a whim. And easy enough to adapt.
Click to expand...
At least up here it stems from them being the best grinder sold within Canada. To get a bader or Burrking up here would make a tw-90 down there look cheap.
And at least the Bee grinders are smooth, quiet, and track extremely well. And a dust shroud that is actually usable. And not having to hold the tension arm down while trying to change the belt with one hand is another benefit. And somewhat adjustable tension without moving a tool arm in or out.
I guess they're either something you love or hate.
 
You must log in or register to reply here.
Back
Top