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Need some advice

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Hello, just joined AAW, look forward to meeting you all and reading your tips and advice. I have been turning for a couple years now, I have gotten really good at what little I do, I turn small stuff now, now sweat.

I am wanting to turn a vessel shaped piece, the OD will be 3 1/2" the total length will be 8", I wanna bore a 2 1/2" 7" deep. I have turned it to size and bored it with a 2 1/2" forstner from woodcraft, not exactly the best brand at all, had quite a bit of trouble with this method and am thinking there has got to be a better way of achieving this. I will be spinning walnut, cherry, or maple, mostly end grain.

I would really appreciate anyone's insight into this, thank you ahead of time.
 

john lucas

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Buy a good quality Forestner bit. The cheaper ones just don't work well for cutting into end grain.
I do have a method of doing exactly what you are talking about using a captured boring bar but it takes quite a bit of set up and of course you need a boring bar.
What I do is set up a guide system for the boring bar. There are 2 pins that act as guides for the final dimension of the piece. they act as a stop and keep the boring bar parallel to the sides. You do need to drill a hole first but it can be smaller and you can use a twist drill. Anyway you just cut away wood until the boring bar hits the stop pins, slide it forward and back along these pins and you clean out inside and get a perfect tube, if you set up the stop pins accurately.
I don't have that system right now so I can't take a photo but could possibly jury rig something to show you what I did. I was making some sound tubes for something the school orchestra wanted.
 
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Buy a good quality Forestner bit. The cheaper ones just don't work well for cutting into end grain.
I do have a method of doing exactly what you are talking about using a captured boring bar but it takes quite a bit of set up and of course you need a boring bar.
What I do is set up a guide system for the boring bar. There are 2 pins that act as guides for the final dimension of the piece. they act as a stop and keep the boring bar parallel to the sides. You do need to drill a hole first but it can be smaller and you can use a twist drill. Anyway you just cut away wood until the boring bar hits the stop pins, slide it forward and back along these pins and you clean out inside and get a perfect tube, if you set up the stop pins accurately.
I don't have that system right now so I can't take a photo but could possibly jury rig something to show you what I did. I was making some sound tubes for something the school orchestra wanted.

I had heard mentioned somewhere bout a boring bar, I am not familiar with it though. Pls let me know more of where to find one that will work for the instance.

Hey really thank you for stopping by and sharing this with me. I am most grateful and its nice to meet you!
 

john lucas

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Ed I hope I can explain this. I don't have my original rig for doing this but I set up something and hopefully you can tell from the photos. A captured bar rig gives you a lot of control. It occured to me one day that by restricting it's movements I could bore out a hole of known size parallel to the outside.
I had already built a homemade version of the Lyle Jamieson rig.
https://www.lylejamieson.com/tools/index.asp
That is the blue thing with the wooden rear tool rest in the photo.
then I had a support for 2 metal bars to restrict the movement of the boring bar and align the movement. In this photo I took my rig that holds the router for routing on turnings. I put 2 deepwell sockets to simulate my metal bars to restrict the movement.
Then on the rear tool rest a stop was installed to restrict the boring bar movement in that direction. What this does is lets me move the cutter to the right but restricts it's movements to the left. You hollow out the piece until the bar hits the restrictor pins you can just push it toward the headstock until the piece is hollowed.
 

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Joined
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Ed,
I agree the WoodCraft bits are not as good as some of the other brands, but just to make sure if you are doing this on the lathe, you did slow it down, yes? Fostner bits don't work well at higher speeds. Put your lathe, not sure which kind you have, on a slow speed 250 to 300 rpms, if you get up to the 600 to 800 the bits just don't work well, especially the inexpensive ones.
Bill
 
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I've had better luck with wood bits than Forstners on endgrain. They have to work SLOW, as mentioned. If you're going to use a boring bar, you might as well use conventional turning methods and use a gouge or a 1" with a normal bit to establish depth and enlarge. You don't require absolute precision, I take it?
 
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The boring bar seems kinda intimidating, that's some work for sure. I have just gotten an expandable spade bit 7/8" - 3" haven't tried it yet. I am using a small grizzly 10", I think my lowest speed is 450, have never used it to bore. I have found the 2 1/2" - BORMAX Forstner Style Bit by FAMAG (Long Series), even spoke to the manufacturer, says with that wide a hole and that depth it will create heat and burn the bit. Its super nice from German steel, heckova price but looks tough. I just gotta believe there is a not so hard way of achieving this.

I thank you for for stopping by.
 
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Dont try to drill it to the 2.5" size at one go.

Start with a smaller bit to open the hole, then progressively larger until you reach the 2.5" bit.

With a low speed of 450, even doing the drilling progresively is going to overheat the larger sizes, so with the larger bits, let things cool every 1/4" or so.
 

john lucas

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you can't use consecutive bits if you use a spade bit. You need the center point when using a spade bit.
 
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Hi Ed,

When you say you have a 7/8" to 3" expandable spade bit that you haven't tried yet I am envisioning the type of bit that goes in a brace or a newer style such as made by Irwin that mounts in a drill press. I will reserve comment on the use of this until I know for sure that is in fact the type of bit you are referring to. Can you clarify this for me please?

Rob
 
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Forstner Bits

You need the center point for Forstner bits, too. But the large bit can't reach the deep divot made by the smaller bit. The hard work in using Forstner bits in end grain is the bottom chisels cutting across the grain. They work a lot better in side grain. Oddly enough, Forstner's original patent (US 155,148) was intended to eliminate the center point, and let the boundary provide alignment.

Although tedious, here's a method of many steps:
Drill the largest size to minimum depth (about 1/8").
Drill the next smaller to its own minimum depth (ditto).
Proceed to the smallest bit that can reach the bottom of the hole, with similar bites.

Then, proceed upward in sizes, with guidance provided by its previous shallow step.

Finally, drill the last step (with the largest size) all the way to the bottom.

This works, because the upward-size cuts are made only with the rim cutters, and the bottom chisels just go along for the ride.

Colt brand Forstner bits are reported to have solved the bottom chisel problem, but they're probably the most expensive available.
 
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You need the center point for Forstner bits, too. .

Actually, When drilling with a rigid setup as encountered with a tailstock held bit, the center point is not needed. Typically, I will cut a small divot in the end of a piece so that the point does not make contact until the rim of the bit has entered the wood for a distance of an 1/8 inch or so. By having the edge spurs make contact before the point, the tendency of variations in the grain pushing the bit off center are reduced. I do quite a bit of driling with the tailstock using forstner bits, and when the hole is large, always drill the center out with a smaller bit first.

If the bit was used in a hand held drill, then the center point contacting first would be best to help keep the bit from wandering about.
 
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This is the expandable wood bore bit I was referring to guys. I missed the couple posts above this, gotta get the hang of this forum here. Thanks for the input fellas.

Vermont American 14402 Adjustable Wood Boring Bits
 

john lucas

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I suppose you could use that bit but it's cutting with just one cutter. A forestner style bit is using 2 cutters to do the same thing. I think the single cutter would dull pretty quickly. those drills were designed for hand use in a brace. Obviously by the design of the shank Vermont American thinks it can be used in a drill press. I have 2 of these bits in different sizes but mine have shanks for a brace so I can't really try one in the lathe to see if it would work.
Now what might work is a really large auger bit. Grind the center spur down so it won't try to self feed into the wood. I haven't had a problem with that drilling into end grain because the center spur just tears out the wood instead of pulling the drill in like it would if held in a hand drill. I have used them up an inch with no problem. You can find the really large ones at the flea mkt. They will need sharpening and you will have to cut the shaft. the drive spur is usually worn down on these so that won't be a problem.
 
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Ed, a friend of mine tried using that type of bit on a turning with thoughts of speeding up the hollowing process. The results were not good. As was previously stated by John the single cutter was the problem. The bit worked good in a drill press, but that was with the piece being drilled secured to the platform. On the lathe he tried holding the first piece with a Oneway chuck and with a very slow feed rate, started out okay. Once the bit grabbed it ripped the turning right out of the chuck. I know that he could not slow his lathe down enough to have the bit work properly to begin with. After a couple of attempts he gave it up because the turning kept getting pulled off center. He said he was going to try to mount a test piece on a face plate and try that, but I don't know that he ever did. I don't think I would.
 
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