Calling all machinists, professional & amateur HELP!

[85RZwade]

I made a boring bar out of an Allen wrench. Then reground it into a tool to cut an o-ring groove.

That's a great idea. It just has to be harder than the aluminum, right? I measured my little boring bar (12.5mm) and stuck it inside the 15mm wheel bearing, and it'll work. Might have to relieve a little material below the carbide, but it'll work.
Spent most of the day working on our motor home (interesting to me that my iPad suggests Motörhead when I start to type motor home...Lemmy fans at Apple, I suppose) so not much happened on the bike front. Did get a partial shipment from Speedmotoco; cool headlight and some angled UNI filters for the LC's VM30s. The mounting brackets for the headlight haven't shipped yet, so I could only hold it out in front of the RD's triple clamps and imagine. Might look better on the LC.

[m in sc]

oh yeah, i have a bunch of tooling thats radiused on the bottom just for this. you'll get it. allen wrench is a great idea, too.   

[85RZwade]

littlemachineshop has a 0 MT to 33 JT arbor for $10 and a 1/16-5/8 Jacobs Chuck for $38; the combination would allow me to bore a 15mm hole. You guys have shown that this particular job can be done with a boring bar, and I won't have to own a 15mm drill, but I'd like to be able to bore the pilot hole with some accuracy now and in the future. Thank you for the website Rodney, and all the other ideas gentlemen! I look forward to making swarf.

[m in sc]

throwin' chips and taking names. 

[Dvsrd]

Wow! Thank you all for so much input so quickly, I'm grateful. I just got some tooling and I'll see if the boring arm is small enough to make a 15mm hole. Also thought to look for a drill with a reduced shank. I will check the resources you guys kindly provided, and how does one get started working on clocks for a living, Mark? There's gotta be a story there.

FWIW, I avoid reduced shank drills like the plague. At least with keyless chucks, they tend to overload the chuck when drilling steel. So you end up with 2 channellock pliers to open the chuck again. In my opinion, reduced shank drills are useful for drilling in wood and plastic only. Not in steel.

[85RZwade]

Point taken

[m in sc]

the only keylless chuck i have is on my dewalt drill and its clutched. on any machine tool, keyed always. also you can get reduced shank drills with 3 flats, they do not spin.  or, get a morse tapered end drill bit to fit on the tail stock.  $$

[85RZwade]

Add that to the list of things I didn't think of

[sav0r]

I have a 9000rpm keyless chuck. It works perfectly fine. I just can't stop the spindle too fast. I also don't have issues with reduced shanked drills. When I have big drilling jobs I'll use an ER collet (mill) and not the chuck, I get less runout and better bit life this way. I make a stainless part that I use a carbide drill bit ($17 each, 1/8") and carbide is a lot less forgiving than HSS bits, but they last forever in the right conditions. On the lathe I have never had a single issue with a keyless, outside of either using an ER or tapered bit. The advantages with the ER are mostly for CNC, I don't foresee any reason why I would ever need ER on manual machine.

That said, I mostly just drill to form a pilot. I bore from there. That's true on the mill and the lathe. I have less issues boring than I do drilling. Drilling is a much faster means of material removal, and it still has many uses. Boring provides much rounder holes. Since I don't do much (none) long production work, boring has provided me with better results. That's true for proper boring and interpolated boring.

[85RZwade]

I made a boring bar out of an Allen wrench. Then reground it into a tool to cut an o-ring groove.

It's been a LONG time since I ground a lathe tool, but I think it needs to look kinda like this:



And it's still too big to fit in the freakin hole.  More grinding.

[sav0r]

Start with a smaller allen?

[85RZwade]

Fought it for almost two hours last night; I think I'm going to just drill the damn thing.

[sav0r]

Send me a sketch of what you need. I owe you a PM anyways, as I recall.