Drilling Chamber on Lathe loosens arbor & chews up chamber

For discussion of the drilling and shaping of the stummel.
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FrJacob
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Drilling Chamber on Lathe loosens arbor & chews up chamber

Post by FrJacob »

I have a Jet JML-2014 lathe and am using a Nova G3-D Chuck and a Little Machine Shop Drill Chuck, 1/2" with 2MT Short Arbor . All is well until I put either a Pimo 7/8 or a J.H. Lowe 7/8 bit in the drill chuck to drill the smoking chamber. No problem drilling the Pimo-tool mortise & draft pilot hole. No problem drilling the draft. No problem drilling a pilot hole to prep for drilling the smoking chamber. I've tried using a 5/8 spade and a ¼ bit for the pilot hole [in different stummels]. At first, I'd tried locking the tailstock and using the wheel to feed the bit. I've just now tried locking the wheel-feed and not locking the tailstock. I really like this latter process – much more control & no burning. Either way though, the vibration of beginning to drill loosens the arbor from the tailstock, or sometimes, the arbor from the chuck. Then the bit beavers up the smoking chamber and I cut off the lathe.

I've called both Little Machine Shop and Jet, and been treated well in both cases, with useful tips about how to get the arbor to seat in the tailstock & the drill. No matter how well they seem to be seated; same result. I've finished my twin beavered tobacco chambers in the drill press [a HF I'd just as soon quit using in favor of the lathe], so I've gotten a free bevel to the top of the chamber.

I've considered chewing gum tin foil around the arbor [does chewing gum still even come like that?]. I'm also wondering if I'd be better off without any pilot hole, as it's definitely the chatter as the spade bit tries to enter the wood. I've also ordered a 5/8 [2.1" & a 78 [total length 2 ¼] round nose router bits, to try that. Need to check on how to get greater shaft length for use in the lathe – thik I read about that on the forum.

Has anybody else had this problem? Can the lathe tell I'm a newbie?

NOTE: I'm using cherry to build my skill level before beavering up some briar. Go to "Got Wood" at turningblanks.net for great service on cherry blanks. They will cut blanks to 4x4x6 [each lightly encased in wax], so you can halve them as suggested by Kurt, for a no-waste blank! This seems to be cost efficient to the nth degree when starting out.
"A pipe gives a wise man time to think and a fool something to put in his mouth." - C.S. Lewis [False assumption: one never speaks with a pipe in his mouth].
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sandahlpipe
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by sandahlpipe »

The only time I get my arbor falling out of my lathe (I think I've got the same model as you) is when it's not tight to begin with. I'm using a self-centering mt2 drill chuck in the tail stock. I need to feed the tail stock about an inch forward before jamming the drill chuck in. I do the same thing for my mini metal lathe. There's probably a better way, but as long as the taper is correct and you've properly seated it (I jam it as hard as I can by hand) it shouldn't come loose.

Other vibrations may occur besides the tail stock depending on the speed at which you're drilling and the sharpness of your drill bit. If you don't have trouble with a regular hardware store spade bit, it could be that you need to sharpen your chamber bit.


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FrJacob
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by FrJacob »

Thanks for the help Jeremiah. I've not used the Pimo or Lowe bits that much, and until now, only on a couple of pine trial blocks, but maybe the vibration in my HF press has worn them more than usual. Jet assures me the taper of the arbor is right (by comparing it against the live center that came with it. They do not, in fact, seem that sharp. Next lesson for me: how to sharpen my bits!

Jacob
"A pipe gives a wise man time to think and a fool something to put in his mouth." - C.S. Lewis [False assumption: one never speaks with a pipe in his mouth].
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by sandahlpipe »

Sharpening drill bits is simple but takes some practice. I grind my own on the bench grinder and then hone the edge with Ez-lap diamond hones. Just make sure it's sharp on the edge and centered on the tip and you should cut through briar like butter.


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FrJacob
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by FrJacob »

I see some new bits in my future. A 5/8 & a 7/8 forstner to start with. Sharpening the modified spade bits to use in the bottom of the bowl.. Thanks again!

Jacob
Last edited by FrJacob on Wed Jun 25, 2014 1:09 am, edited 1 time in total.
"A pipe gives a wise man time to think and a fool something to put in his mouth." - C.S. Lewis [False assumption: one never speaks with a pipe in his mouth].
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by Tyler »

Quit using a pilot for the chamber. Just drill with the modified spade.

If it's burning, make sure relief is ground behind the cutting edge.


Sounds like you tail stock and headstock aren't perfectly aligned. Annoying, but manageable if you aren't chasing a pilot hole.
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FrJacob
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by FrJacob »

Will do. Thanks for the tip about head & tailstock alignment. I'll check the cutting edge as you suggest. Most appreciated!

Jacob
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by Tyler »

FrJacob wrote:Will do. Thanks for the tip about head & tailstock alignment. I'll check the cutting edge as you suggest. Most appreciated!

Jacob
If you haven't sharpened or otherwise modified the bits from JHLowe and Pimo, they are probably relieved properly.
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FrJacob
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by FrJacob »

Okay! The mystery of the loosening drill chuck & arbor is solved! My final clue was the way my next stummel was thrown off the lathe - twice. First time it bounced off the wall behind the lathe. The second time I made sure the jaws were tightening down as much as possible. This time it went sailing into the open area in front of the head end of the lathe where I do not stand. I am locking down on the drill chuck & arbor, and feeding it into the stummel by sliding the tail stock, which I really like doing. Anyway, I finally decided to check the speed of the lathe.

When I picked up the lathe from the really nice older (than me) fellow, and knowing nothing except that I didn't want it running as fast as it would go, I asked him to set the speed at the lowest speed. But now, finally checking the speed by the chart inside the little door on the lathe, I found I'd been running at 3975 RPM! Maximum speed. The minimum is 500 RPMs. I changed the belts to run at 500 RPM. Problem solved. I guess my Pimo 7/8 probably IS pretty dull, but no arbor loosening.

Before I discovered the problem I'd decided to try starting the chamber with a 7/8 forstner bit & finishing with a 7/8 round nose router bit. It did ok, but there is a ring inside the bowl where the forstner stopped and the round nose finished, the latter evidently being just a shade narrower.

My next stummel I did by first drilling a pilot hole with a 9/16th regular spade (as Pimo suggests), then finishing with a Pimo 7/8ths modified spade. Again, no problem.

I learned a lot by this process. Thanks to all who educated me regarding all the things I didn't know enough to even think about. This forum is great. Oh, and running at 500 RPM is as sedate and peaceful a pursuit as I'd hoped making pipes would be. It is, though, not nearly as exciting as running at 3975 RPM! Makes me proud though, to have earlier turned a candle stick, and the shank of a practice pine stummel at that speed without any major mishap.
"A pipe gives a wise man time to think and a fool something to put in his mouth." - C.S. Lewis [False assumption: one never speaks with a pipe in his mouth].
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by LatakiaLover »

Frjacob ---

I really, honestly, truly, and non-sarcastically think you should enroll in a local wood turning class, and don't touch the lathe you have at home until you complete it.
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FrJacob
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by FrJacob »

This is obviously not a mistake anyone ought to have made. I'm taking a class at a nearby Woodcraft store asap [Turning Basics 101]. Really, the only advice I've had until now has been, and this is from carpenters and professional woodworkers: "watch videos on You Tube," which of course I've done a lot of -- and enough of, at least, not to have ended up in the hospital. Meanwhile though, I'll do nothing fancy until I'm no longer a danger to myself or others. The seven part series, "Briar Pipe Making Start to Finish," has been the most helpful video, incidentally. Had it not included specific instructions as to how to first touch a spinning piece of wood with a tool I shudder to think of what would have happened. Then too, I talk with a pipe in my mouth all of the time and have always considered myself pretty good at it.
"A pipe gives a wise man time to think and a fool something to put in his mouth." - C.S. Lewis [False assumption: one never speaks with a pipe in his mouth].
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by sandahlpipe »

Taking a class would have been a great thing for me to do starting out. I did watch all the turning videos on YouTube that I could find as well as all the pipe making videos I found. Still, I managed to ruin several blocks of briar on the lathe before I got it figured out. I'm still no pro, but stuff doesn't come flying off very much anymore. And I don't always use eye protection in the shop, but I never turn my lathe on without it.


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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by Joe Hinkle Pipes »

3975 rpm??! I'm amazed you didn't knock a hole in your skull when those blocks came loose. My lathe doesn't even list that speed.
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FrJacob
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by FrJacob »

Yes, I am quite proud, actually, of having been able to successfully turn a pretty decent looking candlestick at that speed without doing exactly that. Thanks for giving me the opportunity! Had my skull been in front of the headstock when the block came off I'd probably still be in recovery. And, what on earth do you do at that speed on a wood lathe anyway?
"A pipe gives a wise man time to think and a fool something to put in his mouth." - C.S. Lewis [False assumption: one never speaks with a pipe in his mouth].
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by Tyler »

FrJacob wrote:Yes, I am quite proud, actually, of having been able to successfully turn a pretty decent looking candlestick at that speed without doing exactly that. Thanks for giving me the opportunity! Had my skull been in front of the headstock when the block came off I'd probably still be in recovery. And, what on earth do you do at that speed on a wood lathe anyway?
Generally, the faster you can turn wood, the nicer the finish you can generate with the chisel alone. Remember, we are tuning pipes out-of-balance. When turning high speeds in balance, it's no big deal.
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by Sasquatch »

Yeah in a sense, speed is your friend as regards tearout, cut quality, kickback... all kinds of things are better/safer at speed, as paradoxical as it sounds. BUT.... as Tyler mentioned, we aren't working with a nice piece of balanced, symmetric wood, so you have to take a "this is the best I can do in this instance" sort of approach.
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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by sandahlpipe »

I don't know if this makes sense because I'm far from an expert on lathes. When I was turning at 500 rpm, which is the slowest I can go on my lathe, I not only had tearout, but the pipe would make the lathe vibrate enough to get the start of my holes off center. When I turned up the speed to 1800 the vibrations were more uniform and things were better centered. I'm scared to go any higher than that, but maybe someone who knows their stuff can explain the phenomenon to us.


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Re: Drilling Chamber on Lathe loosens arbor & chews up chamb

Post by LatakiaLover »

O heartily dost I laugh at the ne'erending trials and tribulations of... lathe persons.
UFOs must be real. There's no other explanation for cats.
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