Precision machined bar

[Ian]

Hi

Can anyone tell me where I might get a 500mm lenght of precision machined aluminun bar.

I hoping to make a jig for use on the router table fitted with a flush trim to produce very straight edges.

Cheers

Ian

 

[knappers]

What size do you need? you'd be surprised what's available off the shelf.

Si.

 

[Ian]

500mm long 5-10mm thick and about 20mm high

cheers

ian

 

[knappers]

Ahh, I thought you were looking for a specific size...

Have a quick search on ebay using "aluminium flat bar"

Si.

 

[Ian]

will that be quite accurate over its lenght?

 

[knappers]

Should be. Failing that, you can buy 500mm lengths of precision ground flat stock machine steel that's accurate to small fractions of a mm from places like here :

http://www.mscjlindustrial.co.uk/CGI/INSRCH?N=4097+4294838038

Si

 

[Ian]

Many thanks for that

Ian

 

[matthewwh]

It's worth noting that flat stock is not necessarily straight, it can be very accurately dimensioned - i.e. a section taken at any point will be exactly 5mm x 20mm but that doesn't mean that all of those sections are perfectly aligned - as they are in a straight edge. (otherwise we would all be using lumps of flat stock as straight edges).

I don't want to pour cold water on your idea, but it might be worth investigating cheap low accuracy straightedges too.

 

[Ian]

I see your point but if say glue this flat stock to MDF and a bearing of a router bit follows it will it not produce near perfect straight cuts.

I think as long as it is say 3mm thick along its lenght it should be ok or should it :-k

cheers

 

[matthewwh]

If I were going to introduce tungsten carbide moving at woodworking speeds to anything it wouldn't be made from any kind of metal. You can get aluminium cutting tools that are made from TC but they operate at much much lower speeds. A piece of accurately planed boxwood would be safer and probably no less accurate if you are gluing it to MDF.

 

[Ian]

This will be a top guided bearing trimmer so the only thing touching the metal will be a portion of the bearing.

Ian

 

[monkeybiter]

I think aluminium would be the wrong choice, too soft for a bearing surface and you would probably wear a groove before long.

 

[Ian]

I went for this http://www.cromwell.co.uk/category_page/160202

Cheers

Ian