I Hate Lead

[lakespookie]

A tale of pain and broken drill bits,

Drilling the Aileron Counterweights has been the most painful experience in this build so far, If anyone has any tips i would appreciate it at this point i have ruined about 200 dollars in tools between reamers and drill bits and the pain of extracting broken bits.

[Bryan Cotton]

Don't pilot drill holes. Go right to final size.

[Mike53]

Cut it on a table saw very slowly. I used an 80 tooth blade. Pics here.http://www.onexmike.org/ailerons-and-flaps.html For the drilled holes see the same page.
I used the aileron arms as my drill guide .Drill very slow and keep withdrawing the bit to clean out the shavings. Only go half way then come in from the other side .
after first hole complete bolt it and start second hole same way . I cant stress the slow speed and keeping the shavings constantly cleaned out .

[flyguy0609]

Yea Lead can be messy.

Slow speed on the drill.

Speed makes heat. Heat is the enemy, The tip of the drill generates most of the heat. The heat goes into the drill bit and the lead. Lead becomes highly ductile at relatively low temperature causing the lead turn from something like a rock into Play-Doh. Then, as it is being removed from the hole by the spirals, the lead cools and turns back int the rock. At which point, sooner or later, everything comes to a stop. The higher the spindle speeds, the sooner the stop.

After slowing down the drill, Peck at it..i.e. drill a bit, withdraw and drill a bit more...Like in the titanium drilling video.

Doesn't hurt to use some coolant. It improves tool life. Personally, I'm not sure the cost-benefit would pass.


In the event you choose to further explore this rabbit hole,

Check the same question here..https://www.practicalmachinist.com/foru ... lead.86848

[lakespookie]

Thanks for the tips low speed bandsaw worked for cutting it to size, but the drilling has been a killer will try starting at a bigger size plans say pilot drill and step ream but yeah that has not gone well lol.

[flyguy0609]

Well, as a last resort, one can always make a casting mold, melt and cast.

[mike.smith]

I also tried to drill pilots first, and when that didn't work because the drill bits broke,I went straight to the final size and that worked. You can check out my entries in my kit log site, to see if I had any other information in there.

[lakespookie]

Thanks for the tip the switch to the final size made the second one go much better i have some issues with the first one being slightly offset due to the drill bits chunks causing a bit of walking but yeah the second one is perfect its not really a structural thing other than its holding the lead block so i am not going to redo that item.

Also i assume folks are reassembling the assembly in the wing to get through the holes in the rear spar since it does not fit with the screws.