Large, Long Holes in Wood...

[Joe AutoDrill]

Here is an inquiry I received this morning:

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I am trying to find some sources to help us build a wood boring machine that can drill from 4" up to 10" (rarely larger), mostly our needs call for the 4" ~ 8" diameter range boring up the center of the log lengthwise. Length of the pole is typically 8' to 12' long. We are trying to find a source for the machine and drill bits. B&A Manufacturing referred us to you for the equipment part of our needs. Tree diameter generally calls for needing at least 4" larger than the diameter of the hole, but usually 6" is better (3" width of tree leftover all away around the diameter of the hole and the larger the tree, the larger width of wood needs to remain). So if can imagine, we may have a 16" diameter tree, 10' long, that calls for a 8" diameter

This is one of the hardest, most dense woods of the world.

Is there a stock machine out there that can do what we are asking, and if so is that something you can offer? Do you know where we might find one and at what kind of cost?

Someone had one built that drills it while still leaving the "donut hole" for lack of a better term still intact so that when it is finally drilled all the way through, we are left with a wood cylinder in the diameter of the bit used. Do, if our job calls for a 4" hole, we end up with a wood cylinder slightly less than 4" in diameter. That is then pulled out of the inside of the log. We found this to give us the most success in boring out this wood.

Please let me know what you can come up with.

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Anyone have any leads for this guy? I can't / won't build a machine of this caliber but would love to point him in the right direction.

Regards, Joe Agro, Jr. [phone]

01.908.542.0244 Automatic / Pneumatic Drills: Spindle Drills:

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[Morris Dovey]

Joe...

I don't know if it's helpful to you or not, but a 2.5X version (in metal, rather than the baltic birch shown) of the machine at the link below could do that job nicely...

I know how - I built the machine shown. :-)

[Joe AutoDrill]

Morris,

Which link? Your sig link brings me to the JBot... Didn't see another link...

Also, sent a buddy your way for some solar panel stuff... Dan from Scranton, PA. Great guy.

Regards, Joe Agro, Jr. [phone]

01.908.542.0244 Automatic / Pneumatic Drills: Spindle Drills:

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[Robatoy]

serious, but the parts and drives are there. Horizontal boring is one of their specialties. They bored a hole from the church parking lot on my street, past my house and down the street a total of 1300 feet, going through deep roots, rocks, all kinds of stuff and ended up exactly where they wanted. I can't imagine they wouldn't be able to help him.

r

[J. Clarke]

Looks like a neat machine but I don't see how you'd gun-drill a 12 foot log with it.

[Morris Dovey]

My goof - I missed that you wanted to bore 16 FOOT lengths to make pipe. Sorry about that.

I assume he's wanting to drill something like ipé. It's an interesting tooling challenge. :-)

I'll keep my eyes peeled for e-mail - and, of course, treat him well. Thanks!

[Joe AutoDrill]

Welcome to my world. :)

[Morris Dovey]

You don't - I shoulda read the reqs /three/ times before opening mouth. I was over-eager.

[J. Clarke]

or one of their competitors.

Google "gun drill" and you should be able to come up with more hits. A call to the appropriate division of BAE Systems might also yield the name of their tooling supplier (or might not depending on how close to the vest they like to keep their manufacturing).

[Morris Dovey]

I admit, it's one of my weaknesses.

I couldn't leave the CNC idea alone, though - I wonder if it'd be possible to support the log on a pair of cradles in front of a Y-Z gantry carrying something like a CO2 laser, and just burn the hole leaving a (nearly) hole-sized core to pull out.

It'd only be necessary to maintain the beam for half the length of the log, and parameterizing the part program would allow any diameter hole larger than the laser beam...

...or even polygonal holes.

[Joe AutoDrill]

Anyone ever tell you that you are way too creative for your own good?

Might work really well, but dangerous as can be in an environment where safety talks generally go "Don't get crushed, spun, run over, etc." The smoke could be an issue too...

Regards, Joe Agro, Jr. [phone]

01.908.542.0244 Automatic / Pneumatic Drills: Spindle Drills:

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[charlie]

think steam explosions 8' down inside a 16" diameter log.

[Joe AutoDrill]

Oh what I wouldn't have done as a teen to know this stuff....

[Morris Dovey]

It's because I'm so lazy and such a cheapskate. I's a fatal combination.

If the approach could be made to work (depends heavily on collimation of the laser beam), it'd only be necessary to drop the log on the cradles with a fork lift, locate the height of the center of the log, specify the diameter, and stand back. There'd be a minimum of mechanical stuff to maintain, and no expensive bits to sharpen or replace (or stock in different sizes). I'm guessing that power consumption would at least not be worse than a traditional boring machine.

Probably, smoke should be considered a solved problem - and shouldn't be more complex than ventilating a spray booth. Setting up guards, interlocks, and shields for safety should be straightforward.

I don't know what kind of beam collimation is current state of the art, but I'd guess that seven or eight feet should be workable.

[Morris Dovey]

Good thinking - just as with routing and milling, depth of cut per pass, adequate airflow, and a suitable feed speed are important factors for controlling heat build-up. In the case of laser cutters, I think additional control can be exercised by controlling pulse frequency and/or duration.

[dpb]

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I didn't see this until Morris had already made the suggestion, but that was my first reaction as well.

As for the safety issues, those could be pretty easily taken care of w/ appropriate fixtures I would think. If they're doing this extensively, a little extra for the fixture shouldn't be any drawback.

At former employer in a previous life :) we begin using laser penetration/welding in pressurizing nuclear fuel rods w/ inert gas during the manufacturing process "way back" in the late-70s. Laser focussed to make a pinhole in fuel rod end cap, evacuated and then filled w/ argon; laser defocussed and welded shut the hole. Same thing; a fixture and interlocks prevented any way of getting the laser activated w/o the required shielding in place.

I would thing there could be a heat removal issue in such a thick enclosed piece, but where there's a will there's a way.

The description of a current tool that reaches (apparently) the full length and leaves the core is leaving me w/ the desire to see that puppy... :)

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[Lew Hodgett]

National carbon used a "gun lathe" to machine 6" dia thru holes in 20 ft long graphite logs for the nuclear industry.

They found both the lathe and a milling machine at an old armory auction as I remember it. (This was 1960 era).

Lew

[mac davis]

Well, you didn't, Joe.. and that's probably one of many reasons that you're still alive..lol

mac

Please remove splinters before emailing

[Joe AutoDrill]

Ya know....

I have a video of a cannon we made as kids that shot pool balls (billards) straight up. They would land about 2.5 minutes later... (anyone able to calculate FPS, total height by that?) I also have knowledge that you can shoot a bilalrs ball straight through the chain link fence that is behind home plate on a baseball diamond if you want to... And the ball will not even have much damage other than scortch marks and a slight scratch...

#1. Don't ask how we know it was 2.5 minutes later as the statue of limitations may not protect me yet...

#2. I have a video of the same cannon with a double load (only time we ever put twice the propellant in) falling over, pointing at us at face level from the top of the "firing hill" and not going off for the first and only time in over 100 shots...

I shouldn't be alive... And have proof of it.

That was what we did for fun. The stuff I got caught doing and the stuff we did to cause trouble was worse.

No wonder I work with troubled teens and find it exciting when I'm not here.

...And no, I don't do that stuff any more. I only talk about it and only in ways that makes it really really hard for the uneducated to learn how to copy cat my actions.

Regards, Joe Agro, Jr. [phone]

01.908.542.0244 Automatic / Pneumatic Drills: Spindle Drills: ** Posted from **

[Robatoy]