Light Aircraft Association

I need 48 non-standard size steel washers to complete my wing spar fittings: they have to be brazed in place before reaming holes to size.

To save a lot of time I planned to have these laser or water jet cut. The last quote for laser cutting was for £90 + VAT, so it looks as though I shall be flogging away again with hacksaw & file, unless anyone can suggest an easy way of doing this job or recommend a laser cutting operation that would be willing to undertake this small job for me.

Any suggestions would be appreciated.

(Apologies if this post appears twice - my first attempt appears to have vanished after I clicked "Submit".)

Ian

What size ID / OD do you need.

Ian

Ian,

Ideally I need the following, preferably from 4130N steel or an equivalent that is at least as beefy:

# OD ID Thickness
16 3/4" 6mm 0.063"
16 5/8" 6mm 0.063"
8 1/2" 6mm 0.050"
8 1/2" 4.5mm 0.050"

Tolerance/thickness isn't really critical; as already described, they will be brazed in place on the fittings and just need enough spare metal to allow the finished holes to be reamed to size.

I made up some myself (hacksaw/file/finished off on mandrel in lathe/electric drill etc) for the fittings in the fuselage, but want to avoid this unpleasant and time consuming job if there is an affordable alternative.

I don't seem to be having much luck finding any suppliers on the web and minimum quantities are always a problem.

Ian

You could avoid the hacksaw part by using a holesaw

Most holesaws use a 1/4 inch pilot so remove pilot and use a guide plate to locate the holesaw, just drill a hole in a bit scrap with the holesaw you are going to use then clamp this to your good material.

Use say a 1 inch to produce 3/4 inch blanks ready to tidy up.

Ian

Ian,

By coincidence, earlier today, I looked at some of the Starrett holesaws I have and realised I could easily remove the 1/4" drill piece in the arbor and replace it with a stepped shaft that I should be able to machine in my elderly lathe, with care. I'd need 2 new rods - 1/4"dia. at the top and 6mm and 4.5mm at the business ends. Should be a quick and easy job ( not necessarily in my wheezy old lathe, tho' ).
By another happy coincidence, the 3 saws that I have should produce the 3/4, 5/8 & 1/2" dia. "washers" ,so I will have a go in the next few days and see how well this works, using my drill press of course.

Many thanks for your help.

Ian

No problem, its good to use those little discs we usually sweep up and toss in the bin

Ian