Lee Valley honing guide - chisel issues

Re: Lee Valley honing guide - chisel issues

mikew

>Hi Jim, which TC chisels? Size?

fwiw, I cut a thin layer of rubber and glued it to the clamp bar surface that goes against the chisel top. I did this to see if it would grip some Japanese dovetail chisels that come up to a form a bevel on chisel top.

I have used the LV MK.II for chisels down to an 1/8" width one with no problem--once I clamped it down.

Mike

Re: Lee Valley honing guide - chisel issues

mikew

>Another thought (geez, I wish I could just edit my message).

The only way I have been able to make a narrow chisel pivot (or a wider one) is uneven pressure. I know you mention you tightened both clamps down, but it is easy to get the bar fully across the chisel.

Mike

Re: Lee Valley honing guide - chisel issues

Jim Cosgrove in N. Virginia

>Mike--I may try the rubber trick, thanks. The chisel I tried was 5/8", so not especially narrow. The Two Cherries taper in length (and thus are harder to grip than a plane iron), but I think most chisels are made like that.

--Jim

Re: Lee Valley honing guide - chisel issues

mikew

>Hi again, Jim.

All my chisels taper, some quite a lot.

The link goes to a message I did on SMC today. The point is in the last photo in that message. The chisel is a NOS Bahco. You can see the amount of taper in that pic.

I have a couple Greenlees (I think that's what they are, anyway) that probably have more taper. It is able to grip those.

That said, I haven't tried Two Cherries chisels in the jig--but aren't they and the Hirsch the same? Those I have. If, when your chisels are clamped in, take a look at how both sides of the clamp bear on the chisel and on both top/bottom.

If the clamp bar does not make contact fully on top and bottom, front and back, that would be the likely source of the problem. That could mean that LV did not allow enough pivot in general for the clamp bar to fit the Two Cherries, or that maybe your jig was not made properly.

At that point even the rubber may not allow enough "squish" to make up for that. The holes the clamp bar bolts pass through are elongated to allow the "swing" of the bolts. Rob knows I would probably break out the Dremel and make an alteration--but I cannot recommend you do so. At least without catching Rob's attention and getting the nod so if it gets mucked up they will stand behind it.

I'll see if any local dealers have the Two Cherries and try one, if you want.

Mike

Forgot the link! *LINK*

mikew

>Forgot the link.

Mike


SMC thread for chisel taper

Re: Lee Valley honing guide - chisel issues

Derek Cohen (in Perth Australia)

>Hi Jim

The one area I would look closely at is if the blade has a high spot, since it may pivot on this. Make sure that the back of the blade is flat.

In my experience the Guide does not really benefit from added rubber - and you must be careful that this does not cause the blade to cant to one side.

Regards from Perth

Derek

Re: Lee Valley honing guide - chisel issues

mikew

>Hi Derek,

If the thin rubber is both the full width (bolt to bolt) and full depth (front to back) on the lower clamp bar, nothing cants. In fact, nothing moves. Which means making sure one has the side of the edge tool against the side of the angle setting jig very important as one cannot shift it once the first knurled nut begins to tighten.

It also aids in holding Japanese dovetail chisels that are triangular in cross-section.

I believe that if Jim's trouble is due to a greater taper than I have experienced, the rubber *may* make up for some of the taper as it will allow the leading edge to compress into the rubber. That's assuming the taper is the problem and that the MK.II he has is not defective in some way.

I'll see if I can hunt down a Two Cherries and give it a whirl on mine.

Mike

Re: Lee Valley honing guide - chisel issues

Alice Frampton, UK

>Jim,

The only chisels I've had similar problems with have been older ones with a slight curve from side to side on the front (that is the bevel side) of the blade. In effect they pivot on the high point. I would have thought that's unlikely on the Two Cherries, but as Derek suggests, there may be a high spot that's giving the same trouble. FWIW, I found clamping the chisel slightly off centre solved the problem for me. I think the pivot point was coinciding with the solid section in the face of the clamping bar; once it was to one side and pressure was applied at the two narrower points front and back (created by the recess in the casting) the clamping effect was much more effective. May not solve your troubles, but as I say, fwiw.

Of course first you have to work out what I'm talking about... :~)

Cheers, Alf

Re: Lee Valley honing guide - chisel issues

les winter

>Hi.

I suggest you call LV. I had a similar problem and it was caused by a clump of coating, I think. JUst as an experiment, move the chisel to one side even though the angle setting jig won't work. DOes that solve it? If so, there is a high spot.

good luck

Les

LV honing guide problem update

Jim Cosgrove in N. Virginia

>Alf--I tried your suggestion of clamping off center, but it did not seem to help. I tried several different chisels to see if the problem (chisel pivoting in the guide)was unique to the Two Cherries. Unfortunately, the same problem also occured with Crown chisels and Barr chisels. In contrast, Lie-Nielsen chisels are held tight--absolutely no pivoting. Similary, plane irons are held tight. So I'm thinking that my specific honing guide is not defective, but that guide as designed does not work with some types of chisels. Bummer. I know that LV will take it back. But I was really hoping I could get it to work.

Re: LV honing guide problem update

Derek Cohen (in Perth Australia)

>Jim

By deduction, if it is only occuring with a selected number of chisels, it must be something about those chisels that is causing the problem. I believe that both Crown and Two Cherries are often polished at the factory - which rounds not only edges but backs - so I suggest that you check them for flatness (as per my earlier recommendation) before sending the Guide back to LV.

Regards from Perth

Derek

Re: LV honing guide problem update

Lyn J. Mangiameli

>There is much to be said for flat chisel backs. There is also much to be said for a device which can accomodate the less than perfect.

It seems to get neglected these days, as so many seem to report the present configuration works beautifully for them, but I've repeatedly called for shoulder blocks fitted to the front rail which mounts the setting jig as a means to stabilize narrow and irregular chisels. I find I need them for a number of chisels I use (particulary those narrow or triangular in shape), and I ofen use some I made up.

Yes

Derek Cohen (in Perth Australia)

>Hi Lyn

My thoughts exactly. In fact, I have been trying to conceptualize a modification to the clamp section of the Guide (just idly, mind you). This is where a piece of rubber might come in handly, not as a non-slip, but as support for the edges of the chisel (it is usually chisels that have this problem rather than plane blades). But then again, perhaps this is a reason to emphasize that it is like that old computer maxim, "Garbage in, garbage out" - in other words, blades need to meet minimum criteria for the Guide to function as it was designed.

Regards from Perth

Derek

Re: Yes

mikew

>All due respect Derek.

But I think the MK.II design has certain engineered limitations--as does any device. Oversight or not there are issues. There are things that can be done. I'm currently playing around with a few, including...uh, minor modifications of course .

fwiw, my Crown butt chisels and skews and some no-name 6 mm chisel are polished and edges rounded in the process, but hold well. The main issues have been discussed in the past, as well as the OP's current post.

It needs to have an incremental change if it is to have a broader applicability and appeal. That's ok to admit. It's also ok if LV chooses not to.

Mike

Re: LV honing guide problem update

Alice Frampton, UK

>Tsk. Ah well, t'was but a long shot anyway. Chisels certainly are more problematic in the guide, and there doesn't appear to be a lot of logic to which ones will cause the trouble. F'rinstance, I've had no difficulty clamping extremely narrow, tall, tapered mortise chisels, while a simple 5/8" bevel edge has squirmed like an eel in a bucket. Oh well, variety is supposed to be the spice of life I suppose.

Cheers, Alf

Re: LV honing guide problem update

Jim in N. Va.

>Maybe the designers who have added set screws to all of the LV planes could figure out a way to add set screws to the honing guide to keep chisels from pivoting! ;^)

In the meantime, could you tell me more about the shoulder blocks that you have used?

Re: LV honing guide problem update

Rob Lee

>Hi Jim -

The issue you are having is most likely as a result of your chisel...

When clamping between two surfaces, the object being clamped (in this case) has to have flat surfaces. Metal-to-metal contact doesn't provide a lot of friction. We overcome this with the MKII by having a clamp bar with a slight hollow on it, so it creates two lines of downwards pressure...the platen of the guide is flat. If your blades are not flat, you get a line of contact (might as well be clamping a cylinder!) or even a point of contact against the platen, instead of a full surface, and two lines of force seperated by some distance.

When people add rubber to a jig - it's an attempt to increase the friction, and compensate for the geometry. Something else you could try is an adhesive abrasive - like a very fine sandpaper...

Cheers -

Rob

I'm interested too...

Christopher Fitch @ Memphis

>what do they look like?

post photo tomorrow

Lyn J. Mangiameli

>

Where did the picture go? 

ydb1md

>