designing a flat AND hollow grinder?

T

T. J.

Joined
Jul 27, 1999
Messages
228
I've been playing around with this ideal for a long time, and decided to ask if anybody had already done it or was thinking about it too. I have never seen a grinder that could do both without changing parts and such. I'm wondering if it would be practical to build a grinder where the 10" contact wheel is used as the bottom roller for the flat platen, and the machine is just moved or the table tilted to bring wheel or platen into use as needed. The other design ideal I was kicking around was one where the platen is hinged in such a way that it could be raised into position for flat grinding, and lowered (probably have to raise the tracking wheel to compensate) for hollow grinding.

Any comments welcomed.

James

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Those who are willing to trade freedom for security deserve neither, and in the end, seldom retain them!
 
I have built one but the top idler wheel keeps throwing bearings. I am going to replace the ball bearings with tapered roller bearings.

My machine has a backstand idler to track and tension the belt, a small idler roller on the top and a 10" bottom contact wheel that drives the whole operation. The 16" stretch of belt between the top idler and the contact wheel has a flat platen behind it almost touching the belt surfaced with hardwood for easy replacment.

The power head is a 2HP Baldor buffer so one machine grinds and buffs.


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george
www.tichbourneknives.com
sales@tichbourneknives.com


 
Your idea with the platen and wheel on at the same time sounds good.Have you thought about making one that you can work on from either side. The platen on one side and the contact/ drive wheel on the other. That way one wouldn't be in the way of the other, and you could have the work rest set where you want on each and never change it. You'd just have to rig it so that it was on a bench where you could get to both sides comfortably, probably better for a big shop.
A design like the wilton square wheel would be good to. Just design your platen so its about half as long as the circumference of your contact wheel. Make a seperate drive pulley so you can take the contact wheel off.And have your platen made to mount to the same fixture as the contact wheel. Then all you have to do is adjust the belt tension.

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Fix it right the first time, use Baling Wire !
 
make your self a big platen! put a 3" wheel on top. that's a good idea you got there. maybe have your platen so you only need to unscrew one or two bolt(s). if you put you back idler on an arm that can swing foward or backward, to easily compansate for the increased belt space when your not using the platen. maybe i'll add that to my grinder design, i don't want to buy to many cantact wheels anyway. thanks!
 
Hello,

Wheel for hollow grinding and a flat platen for Flat grinding, and a Tensioned slack belt for Convex grinding,

Other than that i do it all free hand,,,no jigs no Supports ,no anything..i think its the best way to go myself.

Also i can take 3 Knife blanks,,,Flat grind
one of them,,,Hollow grind the other,,and convex grind the third,all without changing a thing on the setup....Grizzly Grinders are cool that way!! Remember its Technique,not how many gadgets you rig up.


my .02

See ya,,,,,,,Allen Blade

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Allen Blade
Spokane,WA USA

" It is Always Better to learn The RIGHT Way, Than to Continue Doing it WRONG "

My Custom Knives :
http://www.geocities.com/yosemite/meadows/1770/allenblade.html

[This message has been edited by Allen Blade (edited 01-31-2000).]

[This message has been edited by Allen Blade (edited 01-31-2000).]
 
I made a grinder like that. It has 2 wheels 1 10 inch 1 3-31\2 I bought the idler from sheffields the arm that holds the idler is mounted on a bearing that rides on the main shaft.That way it pivots without losing tension. Have set up 1 position up and 1 down.The whole thing came out a little weak so pick the size of metal you want and double the size.I can possible take some video stills and post if you want to view.It works but still cost $400 dollars.I spread it out so the wife didn't catch on to how much.
Take Care
TJ Smith

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i'm going with a 1/2' thick frame, and 1" thick for the arm, do you think i should go with 1" thick for the frame and 2" thick for the arm? it would add alot of weight, which is good.
 
That's a wonderfully simple and elegant design for a grinder, and if made heavy enough, should work just fine, but
smile.gif
As I dont read german, I couldn't figure out how he drives the belt, and how you would move the drive system when you swapped end for end to change from contact wheel to platen/small wheel end.

any help/translation would be appreciated.

James

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Those who are willing to trade freedom for security deserve neither, and in the end, seldom retain them!
 
Couldn't you leave the drive on the contact wheel all the time and just have an idler on both ends of the platen?

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Fix it right the first time, use Baling Wire !
 
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