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Spade Bits

Posted: Tue Mar 23, 2010 2:07 pm
by NathanA
I just got my spade bits from JH Lowe and they seem a little pointy. Do I need to round them off and if so, any advice on that?

Also, when drilling the chamber with a drill press should I start with a smaller bit, like a 1/4 or so, and work my way up to the spae or do I just go for the spade right off the bat?

Thanks for the help everyone, I feel Like I am always asking stupid questions but I want to do this right. Hope my posts aren't too annoying. Thanks again, Nathan

Re: Spade Bits

Posted: Tue Mar 23, 2010 3:07 pm
by Anvil
I'm not sure about the pointy bits at the tip but I pre-drill with a smaller diameter bit prior to using my "custom made" chamber bit. (a spade bit reshaped using a belt sander which seems to be concentric enough to give a good cut without too much chatter) The bit that I made does not have much of a nose which is why I pre-drill.

Re: Spade Bits

Posted: Tue Mar 23, 2010 3:35 pm
by SimeonTurner
Hi Nathan-

I know that Tim's bits are very conical by design. he is a big proponent of having a conical bowl...something about concentrating the point of the airflow so as to get even draw over the entire surface (at the bottom) of the burning tobacco.

I'm not sure I agree with him on this, but I don't think you will find any trouble with drilling the chamber with the bits as is.

Hope this helps. :)

Re: Spade Bits

Posted: Tue Mar 23, 2010 8:01 pm
by ToddJohnson
No, they don't need to be re-profiled unless you just don't like the profile. If you're going to do this, though, you can just as easily get a set of spade bits at the hardware store and create whatever profile you want. Also, especially if they're conically shaped, I would not use a pilot bit before the chamber bit. This will actually increase your chatter as the bit is basically turned into a two-flute countersink. Instead of making a "plunge cut" the bit is acting as a reamer, something it's not designed to do very efficiently. If you want to use another bit to start your hole, use a forstner (or saw tooth) bit of the same diameter as your spade bit. Just make sure you don't go to deep with it or when you go back in with the spade bit, you'll end up with a shoulder.

Good luck,

TJ

Re: Spade Bits

Posted: Tue Mar 23, 2010 9:03 pm
by NathanA
Thanks for the help Anvil, Simeon and Todd. I appreciate the input.

Re: Spade Bits

Posted: Wed Mar 24, 2010 3:44 am
by christopherthaley
Timely post for me: I was just about to order some of those bits. However, I'd just as soon make them myself, since apparently I can do that on the belt sander. I've only used my belt sander for wood though, so my question is: what type of sanding belt should I use to grind spade bits?

Thanks,

Tom Haley

Re: Spade Bits

Posted: Wed Mar 24, 2010 9:09 am
by Mike Messer
christopherthaley wrote:Timely post for me: I was just about to order some of those bits. However, I'd just as soon make them myself, since apparently I can do that on the belt sander. I've only used my belt sander for wood though, so my question is: what type of sanding belt should I use to grind spade bits?

Thanks,

Tom Haley
They are hardened tool steel. I use a bench grinder with a stone wheel for tool steel and high speed steel, but you may be able to get some kind of belt to do it. I'm pretty sure, regular sand paper won't work, the bits will just cut a hole through it.

Re: Spade Bits

Posted: Wed Mar 24, 2010 11:21 am
by KurtHuhn
Whatever belt sander you have, you can be assured that the belts that come with it are fine for shaping steel. Some are more suited to the task than others, but pretty much all of them will get the job done.

Assuming the typical 1x42 Delta or Wilton sander, any plain jane aluminum oxide belt of 60 or 80 grit will do. You can ceramic belts, and alumina-zirconia, but unless you're grinding a lot of steel you shouldn't bother with the extra expense.

For spade bits, I suggest grinding initial profile with a 60 grit belt, then move directly to 220 to clean up the edge, then final sharpness can be done with a 400 grit belt - but is not totally necessary. Keep the steel cool by dipping it in water. Don't let it get hot enough to change colors, it will lose hardness that way. If it's too hot to touch, it's too hot period.

I'm sure you'll have more questions one you get started - don't be afraid to stop and ask.

Re: Spade Bits

Posted: Wed Mar 24, 2010 11:51 am
by Leus
ToddJohnson wrote:No, they don't need to be re-profiled unless you just don't like the profile. If you're going to do this, though, you can just as easily get a set of spade bits at the hardware store and create whatever profile you want. Also, especially if they're conically shaped, I would not use a pilot bit before the chamber bit. This will actually increase your chatter as the bit is basically turned into a two-flute countersink. Instead of making a "plunge cut" the bit is acting as a reamer, something it's not designed to do very efficiently. If you want to use another bit to start your hole, use a forstner (or saw tooth) bit of the same diameter as your spade bit. Just make sure you don't go to deep with it or when you go back in with the spade bit, you'll end up with a shoulder.

Good luck,

TJ
Huh, the only time I tried to use a spade bit I did a pilot hole and hold the stummel by hand. I almost got vibrated to death.

Wonder if it is time to try it again...

Re: Spade Bits

Posted: Wed Mar 24, 2010 12:10 pm
by Tyler
Leus wrote:
ToddJohnson wrote:No, they don't need to be re-profiled unless you just don't like the profile. If you're going to do this, though, you can just as easily get a set of spade bits at the hardware store and create whatever profile you want. Also, especially if they're conically shaped, I would not use a pilot bit before the chamber bit. This will actually increase your chatter as the bit is basically turned into a two-flute countersink. Instead of making a "plunge cut" the bit is acting as a reamer, something it's not designed to do very efficiently. If you want to use another bit to start your hole, use a forstner (or saw tooth) bit of the same diameter as your spade bit. Just make sure you don't go to deep with it or when you go back in with the spade bit, you'll end up with a shoulder.

Good luck,

TJ
Huh, the only time I tried to use a spade bit I did a pilot hole and hold the stummel by hand. I almost got vibrated to death.


Wonder if it is time to try it again...
Leus,

I think you are misunderstanding. Todd is saying NOT to do a pilot hole if you are using a spade bit. I'd add to that, don't try to drill by hand with a spade bit AT ALL, pilot hole or otherwise!

Tyler

Re: Spade Bits

Posted: Wed Mar 24, 2010 12:26 pm
by Leus
Tyler wrote:
Leus wrote:Wonder if it is time to try it again...
Leus,

I think you are misunderstanding. Todd is saying NOT to do a pilot hole if you are using a spade bit. I'd add to that, don't try to drill by hand with a spade bit AT ALL, pilot hole or otherwise!

Tyler
Yeah, I got the part of not doing a pilot hole. That time the stummel I was hand-holding had a pilot hole, and I was... uh, blurry for a minute.

I've had heard that I shouldn't be using spade bits for drilling by hand but promptly forgot about it. Sometimes I'm adventurous that way (I grew up in an old-school wood working shop, where safety wasn't really a concern.) But thank you for reminding me about it; I'll refrain from doing so. Guess it's time to start saving for... spoon bits?

Re: Spade Bits

Posted: Wed Mar 24, 2010 3:41 pm
by christopherthaley
KurtHuhn wrote:I'm sure you'll have more questions one you get started - don't be afraid to stop and ask.
I'm sure I will! Thanks, Kurt. I just ordered some more belts--I couldn't find a single store in Dallas that carries the right size and grit!--so I'll see how it goes when they arrive.

Peace,

Tom Haley

Re: Spade Bits

Posted: Wed Mar 24, 2010 4:01 pm
by Tyler
christopherthaley wrote:
KurtHuhn wrote:I'm sure you'll have more questions one you get started - don't be afraid to stop and ask.
I'm sure I will! Thanks, Kurt. I just ordered some more belts--I couldn't find a single store in Dallas that carries the right size and grit!--so I'll see how it goes when they arrive.

Peace,

Tom Haley
Tom,

Any ol' Lowe's or Home Depot will have something that works. Spade bits are actually quite easy to shape. Just buy the coarsest grit for the size of your belt sander, and rock on.

Tyler