Drilling steel fork for brakes

[afwalker]

photo.JPG
Hey y'all,
Are there any pointers on drilling a fork for a caliper front brake?
It's a Stainless Llewellyn Max crown.
anything to avoid/never do again/ not screw up?
Slow drill speeds, maybe a spade bit.
How to do a 6mm and an 8mm countersink?
Best done on a mill?
Any jig that would help?
thanks in advance
Andy Walker

[Clockwork]

I use a 1/4" bit for the front. For the back I use 1/4" for a pilot hole and then a countersinking bit (McMaster Carr 8914A34).

-Joel

[Craig Ryan]

A first post and it's the golden fleece for the machine impaired builder. Enco part #368-0116, 1/4" Counterbore. This may be similar to what Joel suggested, or even the same part since I think MC and Enco are linked. If you've got a drill press it's the cats meow. Not so sure how it'd do with a hand drill. I use a 1/4" for the front, 5/16" for the rear, and countersink with this.

[afwalker]

A first post and it's the golden fleece for the machine impaired builder. Enco part #368-0116, 1/4" Counterbore. This may be similar to what Joel suggested, or even the same part since I think MC and Enco are linked. If you've got a drill press it's the cats meow. Not so sure how it'd do with a hand drill. I use a 1/4" for the front, 5/16" for the rear, and countersink with this.

Yep, silent no longer:)
Have a drill press and a vise so I'll get drilling.
Should I do both holes separately, or drill the 1/4" all the way through so they line up and do the 5/16" with the 1/4" as a center hole?
cheers
andy walker

[Chauncey Matthews]

Yep, silent no longer:)
Have a drill press and a vise so I'll get drilling.
Should I do both holes separately, or drill the 1/4" all the way through so they line up and do the 5/16" with the 1/4" as a center hole?
cheers
andy walker

Separately. The bit will walk on the back side if you don't have a super rigid- like a mill- setup.

[shand]

Silva do a stepped cutter for this if you want to do it in a single operation.

[WadePatton]

. Not so sure how it'd do with a hand drill. I use a 1/4" for the front, 5/16" for the rear, and countersink with this.

i did it with a hand drill (different crown, less work) +once+ and won't be doing it that way ever again. got it a bit wonky.

[edoz]

I'd advise smaller pilot holes to start with and don't let the bit or the drilled area get hot. With stainless, if you let anything get hot you're screwed. Slow speed, lots of pressure and coolant of you have it.

[afwalker]

I noticed the stainless heat treats itself and hardens. Sure is pretty, but its a lot of work.

[afwalker]

photo (36).JPG
Holes came out pretty good. Test fit a brake in it and now I get needing to countersink after the 5/16" hole. I'll pick up that Enco/McMaster part as it looks better than a plain countersink.
Viper red is the color.
Painting is a whole other art.
cheers and thanks
andy walker