Ideas for holding mini plane irons in sharpener?

Hello to all!

Hoping someone here can offer guidance / ideas for holding mini plane irons in a General Tools Chisel & Plane Iron Sharpener. It's not the best guide, but works decently will for normal sized irons -- however, due to the clamping mechanism (pic attached) I cannot for the life of me figure out how to hold these tiny irons.

I bought a couple sets of these mini planes at Harbor Freight, mostly for work on instruments, and like any HF tool, they need some fine tuning.

The irons are tiny (approx. 2 7/8" by 1/2" by 1/16", pics also attached) and the clamp is far too big to allow enough length for the edge to touch the stone / paper.

I've tried fashioning a couple of jigs with utter failure, but I KNOW there has to be a way.

I've already tried hand-sharpening, which was quite successful -- in removing a fair amount of knuckle skin.
:-)
I can't afford a better guide at the moment, and the wooden ones I made worked okay-ish but sanded the bottom of the tool more than the iron.

Any thoughts would be greatly appreciated! Cheers,


Jo

I think those would be good candidates for freehand sharpening.

I've just finished sharpening all my irons and a good number of my chisels. I've attached a couple of pictures which show what I made.

The honing guide I made is sort of a variation on the Eclipse type. I have a set of DMT Whetstones, so I built a gizmo to hold the whetstone, into which I can place whichever stone I need. I added a couple of stops on the end of it, to coincide with the two most common angles I use.

To build the honing guide, I used what I had kicking around, some 3/4" MDF and some Poplar. The Poplar is used for the skids and the clamping piece. The two skids need to be of equal height (a little off I discovered, skews the grind a bit). The top of the MDF has to be even with the top of the skids. I clamp the blade in place, square it up, then it pivots to form the hypotenuse (longest side) of a right triangle. To determine the length of the extension I needed, I used the calculator program on my computer and the "Law of Sines" from trigonometry. The law of sines allows you to figure out the length if you know the length of one side and the angle you want. Also, because as I understand it, its more important to be consistent with the angle each time you hone, rather than the exact angle, I rounded numbers. To avoid using fractions, I made my measurements in metric.

Draw a line across the two skids and the MDF which is centered with the hole for the bolt which the piece pivots around. This will be the point at which you measure your extension from. To the top of my guide, is approximately 33 mm. I want an angle of 30 degrees.

The formula looks like this: height / (sin angle)
In my case: 33 mm / (sin 30) = 66 mm.

I've also cut an angle on the front of the underside of the MDF. This way it wont drag on the whetstone when it pivots down.

If you cut the height of your skids higher, you'll need a longer extension, lower and you'll need a shorter extension. Build whatever size you need to fit the small plane irons.

Attachment 357182 Attachment 357183

I would find a small piece plastic or wood no more than 1/8" thick, cut it to the same size as the size as the sole of the plane on the left.
Attach it to the plane sale with double sided tape.

I would then use the plane to sharpen the irons. You also could make a wooden block to do the same thing.

I don't know if it will work in your honing guide, but I just purchased the Veritas Small Blade Holder from Lee Valley (05P32.03). I have their Mark II honing guide and needed something to sharpen all my spokeshave blades, which I just couldn't get the hang of freehand.

Perhaps make a wood piece that will fit the jig, Dig out a recess to hold the "irons" Add a cover to lock the iron in place when you tighten the jig. Then just use the jig.

double tape the small blade to the flat side of a standard plane blade, extending the small iron by a sufficient amount such that it contacts the stone before the full size blade.
magnets (placed on the top side of the larger blade) also work well.

Hi Jo

I think that these blades will fit in an Eclipse-copy guide, which is freely available and cheap. The Eclipse has two blade-holding sections, and the lower section should work for you.

This version has a mod to keep a narrow blade square, but it is the lower section I am pointing to ...

http://i13.photobucket.com/albums/a2...pscjz5ic5w.jpg

Link: https://wb8nbs.wordpress.com/categor...grooved-boxes/

Regards from Perth

Derek

Allen -- They would, except for the aforementioned removal of my knuckle skin, heheh. They're so small and awkward, any attempt at hand sharpening either bloodies my knuckles, or my fingertips / nails.

"I think those would be good candidates for freehand sharpening."

Thank you for all the replies! I'm still trying to figure out the reply system (mobile version doesn't seem to be very compatible here), I'll address them here.




Bill: That looks great...except my brain went into lockdown with the words "Law of Sines" and "trigonometry"! Math was never my strong point, even though I've got 4 CPAs and two engineers on one side of my family alone.


Lowell: That certainly sounds like it would work, especially since I've done so much work squaring up the soles -- the whole plane, actually...they all slanted to one side, ha! I'll probably try that first, even if just as a temporary solution.


Stephen: If it doesn't fit, I could at least hand sharpen with that. I'd have to double-check to make sure it will hold these particular blades, and save up a bit. Even though they don't cost much, I just picked my dog up today from a $1500 knee surgery so money is über tight!


Steven: I did exactly that, but the only wood I have that's thin enough ended up cracking under the pressure of the clamping mechanism. My honing guide has two relatively sharp metal edges an inch apart that require a lot of torque...with an open area between / underneath them. General Tools could've put more thought into this guide, even though it was cheap.


Joe: Also a great temp idea. Not sure if I have strong enough tape, but have a weird fascination with magnets so the house is full of them! Will have to try that first.


Derek: I've eyeballed guides like that, but again, have to wait because of my dog's surgery. I should've picked up something better than I had before that happened, but wasn't expecting it...and now of course I NEED a quick solution. Ugh!
:-)


Lastly: You guys are FANTASTIC people! I've lurked (and learned) here for quite a while now, and am so thankful for all the suggestions!

Clamp blade in vise at 25-30 degrees, hold stone/sandpaper level and upside down, move stone.

OK Jo, here's another idea. It is not as good as the Eclipse, but it will do the job, and immediately.

I have an article on my website called "the 10c sharpening system". It is built around this sharpening guide, which you can make from scraps (two pieces of offcut and two screws) ...


http://www.inthewoodshop.com/Woodwor..._m6d669aba.gif

Here is the article: http://www.inthewoodshop.com/Woodwor...%20System.html

Obviously, you will need to alter the dimensions to suit your needs.

Regards from Perth

Derek

Quote:

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Originally Posted by Jo Bivens

Bill: That looks great...except my brain went into lockdown with the words "Law of Sines" and "trigonometry"! Math was never my strong point, even though I've got 4 CPAs and two engineers on one side of my family alone.

---

Quote:

---

Originally Posted by Derek Cohen

OK Jo, here's another idea. It is not as good as the Eclipse, but it will do the job, and immediately.

I have an article on my website called "the 10c sharpening system". It is built around this sharpening guide, which you can make from scraps (two pieces of offcut and two screws) ...


http://www.inthewoodshop.com/Woodwor..._m6d669aba.gif

Here is the article: http://www.inthewoodshop.com/Woodwor...%20System.html

Obviously, you will need to alter the dimensions to suit your needs.

Regards from Perth

Derek

---

Jo, I kinda know what you mean about the math. I was always considered good at it, although I never really liked it; Trig was always the one I had the most difficulty with. I knew what I wanted to do with this but couldn't remember how, so I had to Google it.

I have a copy of the Eclipse guide that Derek shows, I think it was made by Irwin, which I picked up at Sears for $10. The problem I have with it and the one Derek shows above, is to get the longest stroke possible, the guide needs to run on your abrasive (which wears out the abrasive faster and grinds down your guide).

When I was trying to figure out how to do this, Derek's site is one of the ones I used for reference. The difference between my guide and Derek's (aside from the obvious) is where you reference the extension you need to get the angle you want (Derek's pivots on the front face, while mine pivots on the axle). It is all about the height of your guide. After I put mine together, I measured the distance from the line I spoke of, to the front of my guide, subtracted that from the overall extension. What was left was the distance I needed off the front of my guide, so that's where I put my blocks, just like Derek shows.

Quick and cheap for you, make Derek's guide; I'll try and do the math for you. Hold it from the top and you won't scrape your knuckles.

I'll give you the bottom line numbers below.

For the piece used to clamp down from the top, don't use something that is to hard, it needs to flex a little and have the metal press into it, so the blade doesn't move around (I used a 1/4" thick piece of Poplar). The depth of the guide doesn't really matter, as long as its wide enough to keep the blade stable.

I'll assume you have some 3/4" scrap laying around, use that. Derek doesn't give us the height of his guide, but says its the same as the Eclipse. I measured mine and its approximately 30 mm high. The skids on my guide are 33 mm, or approximately 1 1/4" tall. As I said before, I used metric so I didn't need to deal with fractions. Due to the length of your irons, we can't go much taller than 1 inch, otherwise you won't have enough remaining blade to clamp, I'll give you calculations for a 1 inch height and a 3/4 inch height.

3/4 inch = 19.05 mm, use 19 mm
1 inch = 25.4 mm, use 26 mm
2 7/8" = 73.025 mm, use 73 mm

As you can see, I'm doing some rounding so the angles will not be exact, but they'll be close enough for what we are doing.

equation for extension:
height divided by sine of angle

For a 25 degree bevel at 1" height:
26/(sin 25) = 61.52 mm, use 62 mm for extension.
For a 25 degree bevel at 3/4" height:
19/(sin 25) = 44.95 mm, use 45 mm for extension.

For a 30 degree bevel at 1" height:
26/(sin 30) = 52 mm for extension. (we got lucky, no rounding needed)
For a 25 degree bevel at 3/4" height:
19/(sin 30) = 38 mm for extension. (again we don't need to round)

If these heights or angles don't work for you, let me know what you need and I'll try and recalculate them for you.

By the way, based upon what I've seen happen to me while using my guide, I don't think your average magnet will be strong enough to keep the blade from moving while you sharpen it, but then again I haven't tried it.

How about this idea? Instead of moving the iron....move the stones? Cut a slot in a piece of wood to hold the iron at the angle you want. Make the wood large enough to clamp into a vise. bevel sticks up a might proud? But the bevel is level, while the iron is held at the angle. About like those jigs for sharpening jointer blades. Then just push the stone across the bevel. easier to hold the stone....

Normally, you move the blade over the sharpening media, I can think of two ways to try to deal with this that do things the other way.

what if you secure the blade vertically and then use a stone or diamond file like thing (https://www.sharpeningsupplies.com/D...t-P22C169.aspx). If you can control the height of the blade, then you can lean the diamond file into the blade so that it has the correct angle. For example, see this:

https://www.youtube.com/watch?v=zOJVXRQLUOI

You could even build a fixture to secure the blade so that the beveled edge is parallel to some surface and then run your sharpening tool (stone, sandpaper, whatever) parallel to the ground to do this.