edge jointing jig

[Karl]

I didn't want this to turn into a hijack of the other thread, so thought this could be a meeting place for thoughts on the subject of a large shooting board for the jointing of long edges.

Here is a link to the shooting board used by Terry Gordon. It isn't clear whether the board has a guide for the plane to run against, although I suspect it does.

This type of set-up could quite easily be knocked together with a few pieces of MDF - a piece for the base and a piece onto which the workpiece sits (it is this piece which will get cut away by the plane as with any normal shooting board).

For the hold down clamps, i've been thinking about getting a couple of
these. They could be mounted behind the shooting board, direct into the workbench. The shooting board could then be slid upto them and the workpiece clamped.

The prime problem is one of "feeding" the workpiece. This is obviously not possible if the work is to be clamped down. So it seems to me that the board must be clamped in its final position, so that when the plane makes its final cut (ie it has stopped cutting due to the shooting board), then the board will be flat. Therfore, if the board is hollow in its length, the hollow point will be the reference point which will be place on the edge of the shooting board, with the ends protruding the shooting board - these parts will be planed away, leaving a flat board (or as flat as the reference guide on the shooting board). If it has a bump in its length, then each end must touch the relevant part. If that makes sense.

I'm going to knock something together early next week and will hopefully be able to supply pics to demonstrate the above.

Cheers

Karl

 

[Paul Chapman]

Sounds like a good plan, Karl A couple of holdfasts would be ideal for the clamping.

I don't think there's any way in which you could "feed" the workpiece, because of its size, so clamping it would be the only practical option and then keep planing until the shooting board prevents the plane going further.

Look forward to seeing your progress

Cheers :wink:

Paul

 

[bugbear]

Here is a link to the shooting board used by Terry Gordon. It isn't clear whether the board has a guide for the plane to run against, although I suspect it does.

Since he mentions that you'd need a longer plane to joint longer boards, the accuracy must be coming from the plane, and (I infer) the plane doesn't run against the shooting board.

If the plane ran against the shooting board, you could (in principle) shooting any length workpiece with a smoothing plane!

BugBear

 

[Paul Chapman]

(I infer) the plane doesn't run against the shooting board.

Well, from the second picture in that link, it looks to me as though the sole of the plane is running against the shooting board.

Cheers :wink:

Paul

 

[Karl]

Yes it is a little difficult to tell - the words and pictures tell different stories.

BB - that point had occurred to me, that you could use a short(er) plane if the straightening was being done by the jig rather than plane.

I'm going to prepare mine in the traditional way - ie with a guide for the plane to run against. If it doesn't work out, it's only a few pieces of MDF.

Cheers

Karl

 

[bugbear]

Yes it is a little difficult to tell - the words and pictures tell different stories.

BB - that point had occurred to me, that you could use a short(er) plane if the straightening was being done by the jig rather than plane.

I'm going to prepare mine in the traditional way - ie with a guide for the plane to run against. If it doesn't work out, it's only a few pieces of MDF.

Cheers

Karl

No decision to make - the shooting board is the same in both cases, it's just a matter of how far the workpiece projects, and how much you plane away!

So you can bash MDF with a clear conscience.

BugBear

 

[Karl]

I made a quick mock up of the shooting board this afternoon, using a few bits I had knocking round

Piece of MDF for the base, a piece of MFC for the guide, a couple of holdowns and clamps and screws.

I set the length of Oak to be cleaned up a little proud of the shooting board edge, and started taking shavings with my Philly Jointer until it wouldn't shave any more.

Here is the result

You can see that the workpiece is flush with the guide piece of MFC, and also the step cut into the MFC by the plane.

So, as long as you can get a piece of MFC/MDF or whatever for the guide piece which is STRAIGHT, then it seems to work very well indeed.

Cheers

Karl

 

[Paul Chapman]

Looks good, Karl 8)

Cheers :wink:

Paul

 

[Karl]

Yes Paul, I don't think it worked out too badly. The next step is to get another piece of 8' oak (I have one in the garage which needs thicnessing first) and give it the same straightening treatment, then see what the straightness looks like when the two prepared edges are offered up. 8-[

If that turns out ok, i'm going to order a few of the holdfasts from Axminster on Monday morning.

Cheers

Karl

 

[Paul Chapman]

Should be OK provided the MDF was straight. If it works out OK, I think I'd be inclined to wax the MDF to help prevent it absorbing moisture over time and help to keep your straight edge straight. In the past I've had pieces of MDF which I've used for straight edges to guide tools against and they have mysteriously become unstraight over time :? I can only put this down to moisture.

Cheers :wink:

Paul

 

[ivan]

I think that's why you need a 4' (minimum) try plane like the bloke in the backgroung of the archive film I mentioned, who was planing something about 8' long. With stop shavings you can always reliably produce something up to about 2x the plane length with a slight hollow about as thick as thin paper. Once you believe this, you don't need the 8' straightedge to check it! If you insist, a workshop grade 2M job will cost you around £200; essential if you've got a p/t. I suppose you could always run a bearing guided router bit along it, straight to 20 microns!!

 

[Karl]

I think that's why you need a 4' (minimum) try plane like the bloke in the backgroung of the archive film I mentioned, who was planing something about 8' long. With stop shavings you can always reliably produce something up to about 2x the plane length with a slight hollow about as thick as thin paper. Once you believe this, you don't need the 8' straightedge to check it! If you insist, a workshop grade 2M job will cost you around £200; essential if you've got a p/t. I suppose you could always run a bearing guided router bit along it, straight to 20 microns!!

But with this jig you don't need the 4' plane. The shooting board straightens the piece for you. As well as making the edge square to the reference face.

Modern panel saws cut very accurately, and I suspect that the cuts made on the machine will be quite straight enough.

Cheers

Karl

 

[Karl]

I've had a further thought on the matter.

If your workbench top is in reasonable condition (which of couse it should be) there is no need for the bottom piece of MDF - the plane could just run on the bench instead. This would cut down on the pieces needed for the jig to one - the guide piece.

Cheers

Karl

 

[bugbear]

Here is a link to the shooting board used by Terry Gordon. It isn't clear whether the board has a guide for the plane to run against, although I suspect it does.

Since he mentions that you'd need a longer plane to joint longer boards, the accuracy must be coming from the plane, and (I infer) the plane doesn't run against the shooting board.

If the plane ran against the shooting board, you could (in principle) shooting any length workpiece with a smoothing plane!

BugBear

I felt we'd got as far as we could guessing how that shooting board worked, so I ... email'd him (love the 'net)!

From: paul womack [mailto[email protected]]
Sent: Saturday, 15 August 2009 1:42 AM
To: [email protected]
Subject: web enquiry

In your "Long shooting boards", does
the plane generate the straightness itself (running on the workpiece),
or does the plane run on the shooting board edge (which
is how smaller shooting boards work on small workpieces) ?

BugBear

Hello Paul , The plane runs against the shooting board which is why the
ledge is a bit higher than the distance of the side of the plane to the
corner of the blade.All of which means the edge of the shooting board has to
be planed straight to start with.

Cheers from Micheal.

BugBear

 

[Karl]

Thanks BB.

I've ordered my holdfasts from Axminster, and i'll be able to get the whole jig up and running by the weekend.

Cheers

Karl

 

[Karl]

The holdfasts arrived today from Axminster.

Not great quality (finish wise), but they seem sturdy enough and I got 3 of them plus an extra couple of spare collars for about the same price as a Veritas one, so I shouldn't complain.

The workpiece will be clamped at the end of the bench as well using a normal F clamp.

Installation was very simple, and only took about 15 minutes.

More progress later in the week when i've got the bench top finished.

Cheers

Karl

 

[JonnyD]

Hi Karl I made something similar a few years ago mainly for shooting veneers but have used it for solid wood and it works great.

I made a pressure beam from angle iron and use M12 bolts to apply pressure so the veneer doesnt move and is under pressure whilst being planed.

Jon