[Matchless]

Now, finally, some secrets to success, and some hard numbers.......

First off, make sure the alignment shims on the milling pattern are fairly tight against the part. In this example piece, I allowed the shims to be fairly loose, and my part shifted during milling, so the milling is a bit off to one side (you can see it if you look closely at the last pic).

Don't mill out too deep or use a dull bit. Milling out too much will run the risk of 'tearout' and ruining a perfectly good piece. A dull bit can give much the same result.

You should not be afraid to add a little depron back to the milling pattern or remove a little more. This is a $4 template.... not expensive to replace!

There is a strength/stiffness penalty for doing this process. Think that through when you plan out your milling. You may need to add more to the pattern so you cut less, or you may need to think through getting rid of one or more hole.



Now, some hard numbers - What do you really get by doing this?

The airframe I am milling this evening should result in an airplane which is approximately 130 grams ready to fly.

The depron in the airframe makes up 45 grams of the total weight or approximately 35%.

Milling this airframe took out 7.6 grams, or reduced weight of the depron parts by approximately 17%

Doing so reduces the all up weight by 5.8% overall.

Does not sound like much, however if you put a 5.8% reduction in a giant scale frame of reference, that would be like taking 1 3/4 lbs out of my 30lbs Carden 35%!!!!!!!

So imagine you could take 1 3/4 pounds out of your 35% airplane for a total cost of $8 (total cost of the parts for my router modification and a sheet of 6mm depron). You would jump at the chance and do it in a heartbeat.