How to drill 1-2-3 blocks

Janger

(John)
Administrator
Vendor
So Brian have you tried drilling out a tap with those bits? I've had a go at it with a carbide end mill - and broke the end mill. This was with 0.001 Z advance on my cnc mill so very conservative cutting.
 

Brian26

Active Member
Premium Member
I haven't tried that. I did drill two 1.25" holes, 3/8" diameter in a hardened heavy angle bracket for my mill. Tough going, but I used a much slower speed then the company recommended, and plenty of oil - which, again, the company advises against. For your application I would imagine it would come down to which is harder - the drill bit, or the tap? Tough question - pardon the pun... How big is that tap? I am coming your way on Tuesday and could bring along the right size if you want to try out these bits. I think you are in Calgary, right? Maybe PM me?
 

jcdammeyer

John
Premium Member
I think I bought mine at KBC. The brand is "mbc" and are tapped 3/8-16. The threads are a bit tight. A tap, even with tap-magic doesn't do anything to clean up the holes. The threaded holes are a pattern like the 5 on dice in the middle of the flat faces. No threading on sides or ends. I'm not sure it's worth the time or damaged mills etc. compared to the $32 fro KBC Tools to try and fix an existing set.


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Brian H

Super User
I must admit, for me it was more for morbid curiosity to see if I convert my offshore bastards after seeing the Renzetti structures. I've never used my contraption since. I found the inserts a bit fiddly to orientate & not exactly secure due to round T-nuts in round holes. If a you don't have a requirement where all the hardware must be internal, then undersized fastener shanks & protruding heads is fine. An angle block with threaded hole matrix might be more useful for holding in the crotch or different machining orientations. But seems to me the bigger ones have even bigger threaded holes & spacing? I like tooling plates, lots & lots of smaller holes at closer spacing, but that's probably related to my fiddly parts. I've thought about making my own but Santa did not bring me a surface grinder.

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Fricken Santa...LOL...he still owes me a bike...LOL
 
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