flat grinding problem

M

meteogeek

Joined
Jan 18, 1999
Messages
57
I finally got around to grinding a couple of blades
(1084 steel) on the Grizzly and have run into my first
snag. On one side of my blade the transition from the
ricasso to the gring line along the spine is a nice
pleasing curve while on the other side the transition
is nearly a right angle. I think I know what the problem
may be but I would like to hear from you all with any
tips and advice. As additional info., I do run the belt
over each edge of the platen depending on which side
of the platen the ricasso is positioned. Does this
all make sense?

Thanks in advance,
DeWayne
 
When I first got my Bader BIII, I noticed the same problem. Looking closer at the platen, I saw that the flat platen they provided was neither flat nor the same on each side. In fact, all it is is a piece of angle iron. One side is 90 degrees and the other side is rounded off. I found a piece of D2, and had it heat treated and drilled and tapped and surface ground flat. Problem solved.
 
Danbo is correct. Bader is a good machine, but for the money they ask, the platen is an absolute joke. Spring tension/tracking are also questionable. I learned on and still have to use a Bader BM2, but I am changing soon. Look at the improvement in the quality of knives over the last decade--it is truly incredible. The companies supplying makers will have to keep pace by improving there own products. If companies like Bader don't keep pace, they will be left behind. I do not mean to insult Bader, but I do mean to challenge them to improve certain aspects of their product. I am looking at Rob Frink's machine very seriously. Whether I get it or not, I predict he will be cutting heavily into Bader's business in the future.

John Frankl
 
Thanks for the reply. This is exactly what I thought was happening.
The steel platen I have I got from my dad and I have no idea what
the steel species is. It's just a piece of scrap with what look
to be reasonably true edges. I guess even the smallest difference
will indeed cause different results in the grind lines. I reckon I could attempt to true it up with a file and grinder, but I know others
also have the means/equipment to produce platens that are true.
Would someone out there be willing to produce such a platen for me?
If so, shoot me a price. I'd certainly be willing to compensate?

Thanks,
DeWayne
 
Wow, this was happening to me too. I recently ground on a blade and found the same thing happening to me. I use a home built 2x72 that I put together myself and I made the platen from a piece of angle iron. I've seen over at the CKD Suppliers forum that someone was selling a piece of pyro-ceran glass cut to your length to use as a platen. So far all the posts on that forum are saying it works like a charm!

Good luck, thanks for the post. Got to go change my platen now!

Derek Melton
 
Without a doubt the pyro-ceram glass-like platen
surface provides a superior grinding surface with several
advantages:
1) Side to side differences on your platen are removed.
Plunge cuts can be as sharp as you want.
2) No more "snake tracks" when going to finer grits.
3) Cooler running.

When I glued the glass on my Bader2 with Zap-A-Gap it radically
improved the grinding quality. It was so good that I glued a piece
onto my new KMG-1 before I ever used it. Highly recommended.
You can get it at:
http://pub42.ezboard.com/fcustomknifedirectoryforumfrm14.showMessage?topicID=215.topic
Steve is a great guy to deal with.
Hope this helps.
 
On the side your having trouble move the belt so it overlaps the platen.. Also you can try stopping just short, and it will cause it to roll rather than abrupt angle..
 
Differences in the way that you are holding the blade on the platen will cause what you are describing to some degree, ie., one side of the blade has a steeper angle or you are not quite parallel from side to side. I am not saying that the platen is not part/all of your problem. Just that there may be some other contributing factor.
 
Fitzo,
I just bought some pyroceram over the internet for my bm-2 and bIII and the stuff is wonderful.;)
 
I also slightly radius the corners on my flat platen works great ! The best thing to get is a rotary flat platen from Rob Frink.
Maybe your just using to much heel pressure on that side. Takes alot of practice and we aint born ambidexterous.
 
Please please please take Mike Fitzgerald's advice on the glass!!!

I can tell you whole-heartedly that the glass will radically improve your flat grinds. I have a piece on my Burr King that I use 100% over the hardened, radiused, surface ground piece of D2 that I also have.

Not barking on you Dan, I thought the D2 was the cat's meow when I first got it. But the glass is MUCH better.

Some of you guys get goofy about using glass (scared). You shouldn't. First off, the ceram glass is TOUGH. But more importantly, from a physics stand-point, if you fully back the glass with a base plate and adhesive, you decrease the chances of breaking it to nearly zero. Think about it, if you hit a piece of glass with no support glass goes everywhere. If you back the same glass with a steel plate and hit it the glass does not move (especially if it's glued down!).

This is a VERY CHEAP modification that will drastically improve what you're doing!!!!

Nick
 
Nick, the D2 was a big improvement over the iron platen, but I have since decided to go for some of this newfangled glass. How durable is this stuff?
 
And where do we get it from? I've had much better flat grinding and plunge cuts since I switched to a glass platen, but it crazed over immediately, and now the sides are chipping off, all because of heat. Ceramic sounds much smarter.
 
Dan, I would guess that the ceramic is at least 10-20X more wear resistant than hardened D2, maybe double that, or more.:eek:
Osbourn, see the url furnished by Fitzo, above^^.
 
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