Est. 1998 — 27 years of woodworking knowledge
Re: Grinding a scrub plane blade.
paul womack
>While the result is not guarenteed, fortunately it is quite easy to do.
I'll second that - since my (template-less) grinding was also easy.
I suspect that your grinder + support would nicely grind a scrub blade with a simple dowel or "pin" as the pivot; I strongly suspect the template shape is a red herring.
BugBear
Re: Grinding a scrub plane blade.
Derek Cohen (in Perth Australia)
>"I strongly suspect the template shape is a red herring".
Why not make the template and try it out for yourself? It should take little time.
Let us know what you find.
Regards from Perth
Re: Grinding a scrub plane blade.
paul womack
>Why not make the template and try it out for yourself? It should take little time.
It's making the belt sander that would be the problem!
BugBear
Re: Grinding a scrub plane blade.
Derek Cohen (in Perth Australia)
>Ha! Ha!
How about making the jig, then just adding the sound effects? Vooom!
I was thinking you might use it on your grinder.
Regards from Perth
Derek
Re: Now there's an offer!
frank_shic (walnut ck, ca)
>thanks for the offer, but unfortunately, i'm going to have to miss this year's woodworks because my wife just had our second child and is slowly recovering from the cesarean section - aren't you glad you're not a woman?
hope to learn from you some other day!
Re: MASSIVE!
frank_shic (walnut ck, ca)
>paul, what kind of a grinding wheel did you use with your grinder?
Not so!
Bill Houghton, Sebastopol, CA
>Sir W, you're confusing me with someone competent. I don't even own any rare earth magnets - I own only common earth magnets - much less use them in such an intelligent way.
Re: Not so! Oops! *LINK*
William Duffield, on the Cohansey
>I hate it when my mind plays this kind of tricks on me.
The suggestion was made by Russell Adkins. My apologies, Russell.
sparks and chips are FLYING!
frank_shic (walnut ck, ca)
>guys, thanks for all the advice! what i wound up doing after reading bugbear's response and how he ground the blade with an angle grinder, i went back in the garage and noticed that the included grinding wheel was a metal grinding wheel. i traced the profile of the scrub plane mouth onto the blade with permanent marker and then started grinding to match the profile with the angle grinder. the profile was fairly easy work but the bevel was an ENORMOUS PAIN! i wound up having to regrind the profile because i screwed it up the first time. afterwards, i honed the blade edge with some 80->120->320 grit PSA sandpaper. i stuck the blade back in the scrub plane somewhat dubious of whether or not this would work and GUESS WHAT? it works!!! i can't believe it!!! nice BIG furrows were soon covering the entire surface of a scrap board of pine! the blade is far from machine perfection, but who cares?
thanks to everyone!!!
BTW are you supposed to take an specia precautions when grinding metal? i noticed a fair amount of sparks going off in every direction away from me while i was grinding!
SAFETY !
Jim Reed @ Tallahassee
>Always use goggles or glasses when grinding metal, especially if you are using an angle grinder. You do not want that little hot stuff going into your eyeball. Also wear a respirator or dust mask. Metal grinding kicks up dust from the steel and pieces of abraded wheel. Neither is good for your lungs. I also wear an apron to keep my t-shirt from catching fire. Don't do this barefoot, either. Work safe.
Re: SAFETY !
frank_shic (walnut ck, ca)
>thanks jim! i had the respirator on and my usual glasses on while grinding but i probably should wear goggles to shield around my glasses.
one teeny tiny step closer to hand tool mastery!
Re: MASSIVE!
paul womack
>Paul, what kind of a grinding wheel did you use with your grinder?
A "normal" (circa 60 grit, I guess) gray wheel, around 6" diameter. It came with the grinder when I bought it second hand.
This is a hand powered grinder, but even so I am careful about regular water-dip cooling.
I also stopped grinding when the edge was around 1/20"; grinding to a zero edge carries too much steel burning risk for me. The rest of the grinding was even more manual, as the page describes.
BugBear
Re: Grinding a scrub plane blade.
paul womack
>How about making the jig, then just adding the sound effects? Vooom!
I tried that, but after ten minutes the blade was still unaltered. On the plus side, there was very little sign of the steel bening burned...
Derek - when you grind your cambered blades, do you rely totally on the template shape for guidance, or do you mark a target line on the blade as well?
BugBear
Re: sparks and chips are FLYING!
paul womack
>....after reading bugbear's response and how he ground the blade with an angle grinder,
Ah.
I think you've under estimated my devotion to hand tools.
I meant this sort of thing, only mine doesn't have a fancy rest.
BugBear
Re: Grinding a scrub plane blade.
Derek Cohen (in Perth Australia)
>"when you grind your cambered blades, do you rely totally on the template shape for guidance, or do you mark a target line on the blade as well?"
Hi BB
The short answer: I rely totally on the template.
The long answer: My scrub plane blade preparation can be divided into two parts, firstly the grinding (which I will describe below), and secondly the honing (which is a separate matter).
To answer your question I will relate what I did for the LV Scrub Plane review. There I had 4 blades to grind and hone (2xLV, Stanley #40, and ECE-type woodie) so that all bevels matched and were equally sharp.
I used the belt sander to regrind all the bevels. In fact, the process was continued until all were honed as well. Belt grits used were 80, 120, 240, 400, 600 and 1300. Then a final strop on Veritas green rouge. The last picture in the set below shows an A2 LV blade and a pine end grain shaving. All the blades could pare soft end grain with ease.
The achieve this the blade is set up by first clamping it to the template, then adjusting for the correct angle with a preset projection on the marking gauge. These are illustrated in the other two pictures.
Each time the bevel is ground on a belt, the result is a continuous arc. As with sharpening any blade, one keeps an eye on the back of the bevel for the beginnings of the wire edge. Once it begins it is time to move to the next grit. The wire edge actually becomes smaller as you move through the finer grits. By 1300 it has a mirror-like shine.
The bevel edge exactly replicates the template shape.
In a more typical application, I would hone the bevel to 240, then use the LV Honing Guide Mk II (in Upside-Down Mode) to create a microbevel with 1200 and then 8000 waterstones (see Articles for this method).
Regards from Perth
Derek
Re: Grinding a scrub plane blade.
paul womack
>As with sharpening any blade, one keeps an eye on the back of the bevel for the beginnings of the wire edge.
Doesn't this mean that the current grinding process is being (in some part) controlled by the original (cambered) edge shape?
BugBear
Derek, Rob Lee
HC Sakman
>The second picture is the basis of my sharpening apparatus design which has yet to be completely drawn and sent it to you Rob. I think I gave up on that, but this is the basic idea anyway. The most important point in such sharpening device is to have an abrasive belt with absolutely flat joint with no lumps or bumps. If that is possible, sharpening jig like this would work super fast and efficient.
Chico...
Re: Grinding a scrub plane blade.
Derek Cohen (in Perth Australia)
>I wrote: ...As with sharpening any blade, one keeps an eye on the back of the bevel for the beginnings of the wire edge....
You wrote: ...Doesn't this mean that the current grinding process is being (in some part) controlled by the original (cambered) edge shape? ...
Good grief BB, this thread is taking on a life of its own! :)
... the presence of the wire edge - particularly when it is even across the back of the blade - simply means that the grind has been even and consistent, and has created a single edge. The fact that subsequent grinds (with a higher grit belt) maintain the same bevel angle, and do so by removing minimal amounts of metal, supports my original statement about the part played by the template. That is, that the template guides the grind in a consistent way.
Have we come full circle? :)
Regards from Perth
Derek
Re: Derek, Rob Lee
Derek Cohen (in Perth Australia)
>"The most important point in such sharpening device is to have an abrasive belt with absolutely flat joint with no lumps or bumps. If that is possible, sharpening jig like this would work super fast and efficient".
Hi Chico
It is not only possible, it is a reality!
I know a lot of guys 'n gals use a grinder to create the primary bevel for blades (both straight and cambered). I do wonder if they would continue to use a grinder after trying out a belt sander set up. The belt sander just runs so much cooler, handles wide blades as easily as skinny ones, and grinds faster and does it more safely. Further, I prefer a flat bevel with a microbevel to a hollow grind with a microbevel since it is stronger and also less susceptible to blueing.
Perhaps a pro like Steve Knight might comment. He relies on a belt sander for his livelihood.
Regards from Perth
Derek
Re: sparks and chips are FLYING!
frank_shic (walnut c k, ca)
>ah yes, paul, that would probably work much better than an ANGLE grinder! neverthless, the scrub is functional albeit not perfect!
Re: Derek, Rob Lee
HC Sakman
>Hi Derek,
I also use it for initial shaping of old chisels, plane irons, lapping old plane soles, up to #5-1/2 and other similar tasks. For fine grits though, belt joint needs to be perfect and the sander itself needs to run slower.
Chico...
