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s&d bit troubles

Posted: Thu Jan 31, 2008 6:45 pm
by Briarfox
I picked myself up some S&D bits for the tobacco chamber. I've attempted to shape them and give them the look of my ground spade bits. However they do not cut well. The briar smokes and they just cut horribly.

I ground them by turning them backward on a lathe and took a grinder to them. I am not experienced with sharpening drill bits, so I was reading up on the subject as best I could.

Do you guys have any advise? I'm frustrated enough that I may just breakdown and buy one from http://www.briarpipetooling.com/ and attempt to copy it.

Posted: Thu Jan 31, 2008 7:19 pm
by JHowell
Yeah, you can get lucky, or it can be tricky. I've had both experiences. Usually it's a matter of clearance behind the cutting edge, or the cutting edge being rounded.

Posted: Thu Jan 31, 2008 7:26 pm
by Briarfox
JHowell wrote:Yeah, you can get lucky, or it can be tricky. I've had both experiences. Usually it's a matter of clearance behind the cutting edge, or the cutting edge being rounded.
Do I not want the cutting edge rounded? I tried to emulate the shape of a rounded spade bit.

Posted: Thu Jan 31, 2008 7:40 pm
by ckr
It sounds to me that the area behind the cutting edge is higher than the edge itself. The area behind needs to taper inward so it does not touch and heat the material being drilled. The only part that should touch is the cutting edge itself.

Try taking some meat off the bit behind the edge.

Posted: Thu Jan 31, 2008 8:06 pm
by Briarfox
ckr wrote:It sounds to me that the area behind the cutting edge is higher than the edge itself. The area behind needs to taper inward so it does not touch and heat the material being drilled. The only part that should touch is the cutting edge itself.

Try taking some meat off the bit behind the edge.
Yeah I suspect that is part of the issue. I used a dremmel to grind some away. How much of a point if any should there be?

Posted: Thu Jan 31, 2008 9:59 pm
by JHowell
ckr wrote:It sounds to me that the area behind the cutting edge is higher than the edge itself. The area behind needs to taper inward so it does not touch and heat the material being drilled. The only part that should touch is the cutting edge itself.

Try taking some meat off the bit behind the edge.
Right, that's what I meant, not the profile of the bit itself. When the area behind the edge touches before the edge itself, you get rubbing. And it doesn't have to be the whole edge, just part of one edge can do it. On mine, I used a bench grinder to make some relief behind the edges, and did some dressing with a diamond hone to get the "lands" behind the edges flat. It might help to coat the bit with black magic marker or Dykem blue, and rotate it inside the hole it made. You should be able to tell if there is any rubbing behind the edge, grind away the rub marks, and repeat until the bit cuts cleanly.

Posted: Fri Feb 01, 2008 12:25 pm
by hazmat
If you decide to buy a bit from Trent Rudat, I'll go on the record as saying he does excellent work and the price isn't a killer. I have a 7/8" bit he did for me and it cuts like a dream.

Posted: Fri Feb 01, 2008 1:08 pm
by kkendall
hazmat wrote:If you decide to buy a bit from Trent Rudat, I'll go on the record as saying he does excellent work and the price isn't a killer. I have a 7/8" bit he did for me and it cuts like a dream.
I have a couple of his S&D bits....They cut quite well!

Posted: Sun Feb 03, 2008 10:48 pm
by Briarfox
Still can't get it quite right but it's closer.

Would some ball point end mill bits work for pipes?

Also is there any retailer for longer tapered bits? Mine is about 3"-3 1/2"

Posted: Sun Feb 03, 2008 11:14 pm
by JHowell
Other thing is speed. You don't want to go too fast with a big drill. Try slowing the spindle speed, see what that does.

Posted: Mon Feb 04, 2008 12:16 am
by RadDavis
I ground all of my S&D bits on a bench grinder, and I haven't had any problem drilling, except at higher rpms, they'll chatter pretty badly.

Like Jack says, go slow. I drill my bowls at 250 rpm.

Rad

Posted: Mon Feb 04, 2008 3:08 am
by Frank
Briarfox wrote:Would some ball point end mill bits work for pipes?

Also is there any retailer for longer tapered bits? Mine is about 3"-3 1/2"
I have found that round nose end mills and router bits work well, leaving a nice smooth finish. Other folks have had chatter problems. Of course, if you want a tapered tobacco chamber, you will have to grind your own or buy a custom Rudat or Lamb one. I get my router bits here: http://mlcswoodworking.com/shopsite_sc/ ... _core.html . Free shipping is always a plus.

McMaster-Carr seem to be the only place still selling the long taper point bits: http://www.mcmaster.com/
These things are pretty expensive. If someone finds another supplier, please let us know. Currently W. L. Fuller seem to be the only brand available.

Posted: Mon Feb 04, 2008 9:30 am
by hazmat
Frank, Jamestown Distributors also carries the longer tapered drill bits. I can't give you a URL right now but I'll try to hop on later and add one if you haven't googled it up already.

Posted: Mon Feb 04, 2008 10:59 am
by kkendall
hazmat wrote:Frank, Jamestown Distributors also carries the longer tapered drill bits. I can't give you a URL right now but I'll try to hop on later and add one if you haven't googled it up already.
I don't think they carry anything larger than 3/8" tapered bits.

Posted: Mon Feb 04, 2008 11:24 am
by hazmat
kkendall wrote:
hazmat wrote:Frank, Jamestown Distributors also carries the longer tapered drill bits. I can't give you a URL right now but I'll try to hop on later and add one if you haven't googled it up already.
I don't think they carry anything larger than 3/8" tapered bits.
He's looking for long bits, I believe, as opposed to larger diameter. Unless I read wrong, which could certainly be the case.

Posted: Mon Feb 04, 2008 12:07 pm
by Briarfox
I've looked at the jamestown distributors before. They don't have and longer then What I've got, unfortunately. The 5/32 is 3-1/8 ".

Posted: Mon Feb 04, 2008 12:13 pm
by hazmat
Sure they do. That's where I ordered mine from. It's at least 5.5 inches long. You might want to call them.

Posted: Mon Feb 04, 2008 12:18 pm
by Briarfox
Awesome! Thanks Hazmat, been looking for one for awhile. Must be looking at the wrong page. it shows 3/5 at a 5" as the longest. I'll call them up today.

Posted: Mon Feb 04, 2008 12:27 pm
by Briarfox
Talking to them right now, they don't carry anything longer in the 5/32 category... The search continues.

Correction, they found it. Got a part number! Think it's a special order.

5/32 - 5 3/8 long

Posted: Mon Feb 04, 2008 1:42 pm
by kkendall
hazmat wrote:
kkendall wrote:
hazmat wrote:Frank, Jamestown Distributors also carries the longer tapered drill bits. I can't give you a URL right now but I'll try to hop on later and add one if you haven't googled it up already.
I don't think they carry anything larger than 3/8" tapered bits.
He's looking for long bits, I believe, as opposed to larger diameter. Unless I read wrong, which could certainly be the case.
You're quite right - started out as the baccy chamber bit topic and he snuck in the question of long tapered bits. Sorry.

Here's what you're looking for:
http://www.jamestowndistributors.com/us ... int+Drills