Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: lljsullins on March 21, 2020, 12:56:39 pm

Title: Drilling through eyelet boards
Post by: lljsullins on March 21, 2020, 12:56:39 pm
So I'm needing to mount my eyelet board to my amp chassis, but there are no holes. I need to drill some into the boards! Is there any specific thing I should do/lookout for when I do this?

Thanks all.
Title: Re: Drilling through eyelet boards
Post by: sluckey on March 21, 2020, 01:07:30 pm
Mark and counter punch the hole locations. Then drill. Drill press preferred but hand drill works fine if steady hand. Best to do this before loading components.
Title: Re: Drilling through eyelet boards
Post by: shooter on March 21, 2020, 01:45:27 pm
+1
I'll typically drill the board, mount standoffs, then dab paint on the "chassis side" of the standoff.  set board/standoff in place, remove, now I have "drill guides" on the chassis
Title: Re: Drilling through eyelet boards
Post by: PRR on March 21, 2020, 02:29:01 pm
On a different job, I clamped board and box together, drilled both at once, so the holes WOULD line up.

Yes, just drill it in the right place. Wood-bits work. Fiberglass board wears bits faster than wood but for 4-6 holes it isn't a problem; when you get a contract for thousands of amplifiers you can buy better drill bits.
Title: Re: Drilling through eyelet boards
Post by: EL34 on March 22, 2020, 07:59:16 am
Quote from: lljsullins on March 21, 2020, 12:56:39 pm
So I'm needing to mount my eyelet board to my amp chassis, but there are no holes. I need to drill some into the boards! Is there any specific thing I should do/lookout for when I do this?

Thanks all.


Read this
https://el34world.com/Hoffman/instructions.htm (https://el34world.com/Hoffman/instructions.htm)
Title: Re: Drilling through eyelet boards
Post by: Soulfetish on March 22, 2020, 11:24:42 pm
Also, FR4 (or any glass-epoxy) board is extremely abrasive and will destroy HSS or cobalt drills with a quickness that will hurt your feelings.
If you only have a couple of holes and don't mind dulling some drills, then ain't no thing to get through a job. But, if you think you might want to build a couple of amps or projects, then investing in a couple of carbide stub (machine screw) drills is a good investment.
I use a Melin #31 135˚ carbide drill for a hole diameter designed to fit M3 fasteners