under construction... open to suggestions

building this fixed blade and just can't seem to finish it in my mind..... it is large at 12/8ths wide.... ~6.5" long with the cutting edge ~2.75" long...... it fits my hand better but i wish i would have made the handle i bit longer.... *(it was precut to 6.5")....

any suggestions as to blade shaping??

this is a true wedge and i would like to keep it as such...... remember i ain't much for fancy stuff i just like to make useful tools....

fire away gentlemen...

http://i486.photobucket.com/albums/r...12160450-1.jpg
http://i486.photobucket.com/albums/r...0-12160534.jpg
http://i486.photobucket.com/albums/r...0-12160604.jpg
http://i486.photobucket.com/albums/r...0-12160412.jpg
http://i486.photobucket.com/albums/r...0-12161659.jpg

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Originally Posted by paco664

this is a true wedge and i would like to keep it as such...... remember i ain't much for fancy stuff i just like to make useful tools....

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Are those 2 statements related?
Because when it comes to being useful, a true wedge is not that great in the 'keeping it sharp' department unless you work with tape. And even then... A minor nick or chip will mean you have to remove enormous amounts of metal.

Even a slight hollow would greatly improve the honing experience, and make the tool much more useful.

i have to calculate a diameter of wheel I will need for a slight hollow... Due to the humongous natureof this blade...

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Originally Posted by paco664

i have to calculate a diameter of wheel I will need for a slight hollow... Due to the humongous natureof this blade...

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Rough calc would indicate about 30" diameter wheel, assuming 1/4 inch thickness at the spine. That will give you round 0.5mm concave in the centre of the blade. That's one big contact wheel. Yikes :)

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Originally Posted by Str8Raz0r

Rough calc would indicate about 30" diameter wheel, assuming 1/4 inch thickness at the spine. That will give you round 0.5mm concave in the centre of the blade. That's one big contact wheel. Yikes :)

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i don't see that happening...... but i could possibly lay out a ~30" diameter then cut a 12'' long strip 1/2'' tall from around the outside... then glue the strips together and put them under the belt on my bench belt sander...... possibly secured in place with velcro to the grinder bed... then loosen the belt where it will glide over this........

if this doesn't make any sense i can draw out what i am talking about and that may make more sense....

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Originally Posted by paco664

i have to calculate a diameter of wheel I will need for a slight hollow... Due to the humongous natureof this blade...

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You can use two passes with a smaller wheel. Leave a stabilizer
ridge (or two) down the center line. The ridge can come in handy
for heat treating and perhaps minimize some potato chip action.

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Originally Posted by paco664

if this doesn't make any sense i can draw out what i am talking about and that may make more sense....

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I know what you mean, you are essentially making a laminated curved platen. As long as you have it well secured to the grinder bed it should work, it might prove to be quite dangerous if it comes off while your grinding.

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Originally Posted by Str8Raz0r

I know what you mean, you are essentially making a laminated curved platen. As long as you have it well secured to the grinder bed it should work, it might prove to be quite dangerous if it comes off while your grinding.

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That would suck big time....

Longer handle is easy enough to do if you do not mind adding a different material. Two slabs of your chosen wood, synthetic, etc, can be rabetted out with hand tools to match the tang. Handle can be as much longer as you wish. Drill a tang hole before heat treat to pin the slabs. After heat treat, pin and epoxy in place and then shape to your desire. Voila. Longer handle.
The template for your hollowing will work, but as Stu said, if it comes loose it can be dangerous. i have used similar in the past in reverse to do convex grinds on knives. Otherwise there are threads here about using sen {a japanese inspired scraper} to shape the hollow.
Good luck with it and hope your patience lasts. That will make all the difference.
Adam

Well if you decide to go through with the hollow grind DIY, I'd love to see pics of the machine you did it with, and the final product. You guys got a really cool idea going. I've often wondered about it myself, but don't think I could make a symmetrical hollow without a jig. Jig making never seems to end well for me. Meaning to say, most of my jigs do their job once, and poorly, before I hurt myself and the jig is broken. There's something about inertia and velocity resulting in torque I just haven't managed to calculate very well. haha.

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Originally Posted by paco664

i have to calculate a diameter of wheel I will need for a slight hollow... Due to the humongous natureof this blade...

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No you don't.
Atm I stil use the 1.5 inch wheel of my belt sander for grinding hollows.
You just need to 'roll' the blade from spine to edge back and forth in order to take metal out of the middle.

Using 1 wheel is easier, but so far I have beendoing this with just the little wheel.

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Originally Posted by Bruno

No you don't.
Atm I stil use the 1.5 inch wheel of my belt sander for grinding hollows.
You just need to 'roll' the blade from spine to edge back and forth in order to take metal out of the middle.

Using 1 wheel is easier, but so far I have beendoing this with just the little wheel.

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i have a 6'' grinding wheel *(high speed) and a 8" water wheel *(for after heat treat... it is slower than christmas but you will not burn anything)... and i have a belt grinder with 6" flat attachment.....

i was thinking of making a plastic *(or lexan or plexi) jig to be placed under the belt and secured with counter sunk screws to the bed of the belt sander *(it is a ~14" long bed with a 4" wide belt)....

i may give your method a shot first to see if i can do it..... luckily it is a thick blade so i have just a touch of screwup room....

For those thinking "jig" do not ignore the ability to drill
mounting 'bolt' holes in the blank and then
cut them away when they are no longer needed.

A well made jig would permit making a seven day set
plus one or two and be a lot safer. Build it with
safety in mind.

A jig underneath the belt could work. Interesting.
Otoh, if you freehand, just don't use too much pressure, use a sharp belt and let the belt do the work.
As long as you don't linger in one spot, you won't make divots in the steel and you'll get a smooth hollow.

i shall gather my sharpies *(to monitor metal removal) and start working on it this afternoon.....

photos and bandaids will follow....

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Originally Posted by paco664

photos and bandaids will follow....

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looking forward to it.......the photos not the bandaids :)

A curved platen is a good idea and recommended in the $50 Knife Shop (Wayne Goddard). Just secure it in an appropriate manner. clamped or bolted should work.

What material are you using? The idea for lengthening the handle is good. You could also have a small extension TIG welded on to lengthen it and ant have little or no effect on Final HT. Also silver solder may work, but I have no idea how that would be done and still get the correct HT. Maybe silver solder, full anneal then heat treat?? I dunno how that works out but a few knife makers do it.

Try to make it freehand if you have the courage to. I tried to do it with a jig, and it isn't that much easier as one would think.

This is why I love this place. It's amazing how many really good ideas are so obvious they practically slap you in the face once someone puts it in print. Thanks!!!

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Originally Posted by TURNMASTER

A curved platen is a good idea and recommended in the $50 Knife Shop (Wayne Goddard). Just secure it in an appropriate manner. clamped or bolted should work.

What material are you using? The idea for lengthening the handle is good. You could also have a small extension TIG welded on to lengthen it and ant have little or no effect on Final HT. Also silver solder may work, but I have no idea how that would be done and still get the correct HT. Maybe silver solder, full anneal then heat treat?? I dunno how that works out but a few knife makers do it.

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o1 tool steel...... i am slowly but surely getting more done on it....... but we are in the process of purchasing a house so my spare time is few and far between.....