Cutting slots.

[MJP]

Yesterday I wanted to cut a slot in a small item so that I could insert some brass wire for decorative effect.

The wire is 2.2mm diameter.

Easy, I thought - cut a nice clean slot with a saw, press the wire into place, bingo!

Well, it was not to be - do you think I could find a saw with a 2.2mm kerf? No sirree! I tried every saw I had but all were too slim other than my table saw, which was too wide.

How does one cut thin grooves of a definite width?

Is there another way than hunting for that elusive saw with just the right kerf?

I did try my Dremel as a router on a piece of scrap and it would in fact cut a channel of exactly the right width, but as yet my skill with a router doesn't extend as far as getting anything like a nice clean straight error-free grooves!

Martin.

 

[marcros]

what is the item? is it flat or curved? could you clamp a straight edge to it and run the dremel long that?

 

[novocaine]

make a fence for your dremel.

you will never find a saw exactly suited to what you want, you could set a saw for it if you so wish, or make a very small router plane.

obviously this is from me and I'm waiting to see what other ideas people have for such a narrow slot.

 

[Mr T]

I'd use a router but if you wanted to go old school you could make a scratch stock.

Chris

 

[MJP]

Well, that was a quick resolution to my problem - in theory, at least!

I don't favour router fixes, since the pieces I work with are usually small and support is minimal which, together with the fact that I'm incurably clumsy, makes me want a slower but surer manual method...I prefer to make my mistakes slowly, with more chance of recovery!

A quick search through the archives prompted by MrT's mention of a scratch stock yielded this thread from a couple of years ago:

how-to-cut-a-stopped-groove-for-inlay-scratch-stock-t87665.html

So now I've got more homework to do, and a solution in sight.

Thanks folks.

Martin.

 

[novocaine]

scratch stock, genius.

 

[Phil Pascoe]

... the pieces I work with are usually small and support is minimal ...

How are you going to hold them for the scratch stock? I'd think they'd need more support for a scratch stock than a dremel (or similar).

 

[MJP]

Dunno Phil - but a scratch stock "feels" more my kind of thing so I'll face that problem when I come to it!

Have to learn about the different kinds of scratch stock and try making one now - the fun is in the journey, not the destination.

Martin.

 

[novocaine]

I've been and looked at that thread, there as some lovely looking tools, but wow they don't half make it complicated.

hammer a nail through a bit of wood.
if you want to get fancy, use a stanley blade filed to suit the grove width held in a block of wood. a fence will let you make nice straight lines, if your clever it will also let you clamp the work piece down.

 

[MJP]

Yes, it'll be something along those lines.
During my rust hunts I regularly come across cheap mortise gauges and I'm thinking of starting off with one of those and fitting it with home-made blades.

I can see some enjoyable fiddling about in the offing.

Martin.

 

[Phil Pascoe]

A hot melt glue gun is your friend.

 

[novocaine]

A hot melt glue gun is your friend.

till you leave it on and it dribbles all over your workbench, then it's every name under the sun associated with bad words. (note, an iron is your friend at this point)

 

[Phil Pascoe]

Isopropyl alcohol is useful for a clean up, as well.

 

[profchris]

A method I sometimes use is to make a saw cut, place a card scraper in the slot, and then saw a slot next to it. I now have a slot 1 saw kerf + 1 card scraper wide. If I need wider, add shims on the non-saw side of the scraper.

I'm sure this slightly reduces the set on the scraper side of the saw, but I haven't noticed my saws veering sideways so I guess not much.

 

[MJP]

Blow me that's clever Chris - I'd been tossing the idea of using two sawblades at once around but your way is the one - I can adjust the slit width by just shimming beside the sawblade...and I've got 10mm wide strips of thin aluminium shim that'll do the trick perfectly.

Martin.

 

[Mr T]

You can get a nice crisp slot by using a cutting gauge to define the width in two cuts, turning the cutter so you have a vertical edge to the sides. Then use a simple scratch stock to remove the waste between.

Chris

 

[Steve Maskery]

Ring-pull cans make good shims.

 

[Mr T]

'Scuse my ignorance, what are the flags about Steve?

Chris

 

[Steve Maskery]

It's the flag of Barcelona.
Just my little bit of defiance.