Long hole boring?

**RETIRED** · 20th November 2008, 07:52 AM

Every now and again a job comes along that proves a little bit of a challenge.

This was one such job: To bore a 95mm hole 500mm deep into the end of a 3.5 metre 200x200 Red gum post.

We have bored posts before but nothing on this scale. After all the lathe can be used as a horizontal drill press.

We use "trolleys" that are built to run along the bed of the lathe for various things occasionally so that was no problem. You will notice that they have "lugs" that go under the ways. These are to stop the timber (which is strapped to the lead trolley) from being thrown off the lathe with the trolley should the drill catch.

Better to have the motor stall than have a rampant 200Kg post storming through the workshop.

The next problem was getting a drill "extension" 500mm long strong enough to do the job. As we were drilling 95mm holes it was decided to use 50mm steel, so a trip to our local engineers that are used to my strange job requests. We added a 1" stub morse taper to locate the extension in the headstock and a draw bar to make sure it did not come out.

Retrieving a drill bit in a deep hole is no fun. DAMHIK.

That part all worked well, now to see if it actually worked drilling a hole.

We fitted the 95mm drill bit. You will notice that our "forstners" are not your average bits. They are Tungsten tipped and we have them made.

It didn't work because the flex on the extension, the end not being square on the timber and being such a big drill bit it wandered all over the place.

Back to the drawing board.

Take 2: Remove extension and fit a normal drill chuck in morse taper. Fit 95mm drll and try again. Better but too much load on motor. It is 1HP. Cup of tea and a rethink again. Fit smaller 75mm drill and try that.

AHHH, such sweet success.

Drill to depth of headstock. 240mm. Remove 75mm and fit 95mm drill.

Perfect and now we have a pilot hole 240mm deep to guide the bit fitted on the extension.

Remove drill chuck and fit extension. Drill 75mm, withdraw, fit 95mm and drill to required depth.

Job done, only 7 more to go.

The tailsock was used to push the timber into the bit and the trolleys held the timber at the correct position. Air was used to clear the waste.

**fxst** · 20th November 2008, 08:12 AM

you sure know how to bring the oddities out of the woodwork.

Thanks forthe wip....makes our stuff lookvery mundane

Pete

**Calm** · 20th November 2008, 08:15 AM

Where do you get the kits for S&P grinders that size??

Why 7 four salt one pepper??

Well done - logical thinking wins again.

Cheers

**Grumpy John** · 20th November 2008, 08:46 AM

Originally Posted by

.......
Better to have the motor stall than have a rampant 200Kg post storming through the workshop.
........

I dunno, maybe we could add caber toss to the frisbee throw challenge at DJ's turnfest

.
Brilliant thinking , the best ideas arise when you're under the pump. BTW I've been trying to work out what DAMHIK means and it's got me stumped

.

**DJ’s Timber** · 20th November 2008, 08:57 AM

Only 50cm deep

Good stuff

**DJ’s Timber** · 20th November 2008, 08:58 AM

Don't Ask Me How I Know

**Grumpy John** · 20th November 2008, 12:10 PM

Originally Posted by DJ's Timber

Don't Ask Me How I Know

Bleedin' obvious now, innit

. Thanks DJ.

**rsser** · 20th November 2008, 02:49 PM

Jeez , with your lats and pecs I would've thought a pilot hole and then a square scraper driven straight in would be a doddle ;-}

Edit: just to add, musical instrument makers use a D bit for this kind of drilling, though not on this scale. Length is prob close to a double bass clarinet. Bore? Prob no one could blow through it, cept maybe RBTCO.

**robutacion** · 20th November 2008, 03:25 PM

I hope, you never going to be asked to make tooth-pics, !

Getting those large timbers on to the lathe, even with the use of your hoists, shouldn't be easy. What do you use to make small adjustments? a crow-bar?

Getting dry red gum that size and that long without any major cracks and curves, isn't easy, I don't even dare to guess the price of each piece.

You should do this more often , (WIP pics), it would make most of us appreciate the size of the timbers we normally handle!. OK, OK, I know... some of us handle some big(ish) logs...!

Nicely engineered!

Cheers

RBTCO

**robutacion** · 20th November 2008, 03:41 PM

Originally Posted by rsser

Jeez , with your lats and pecs I would've thought a pilot hole and then a square scraper driven straight in would be a doddle ;-}

Edit: just to add, musical instrument makers use a D bit for this kind of drilling, though not on this scale. Length is prob close to a double bass clarinet. Bore? Prob no one could blow through it, cept maybe RBTCO.

Excuse me, Mr. rsser...

You can't blame a man for being versatile..., huh?

I don't turn my back to a challenge, often (well, a little bit less, in our days)!, so from which end would you like me to try?
No, no, not the double bass clarinet...! my end...!

Cheers

RBTCO

**rsser** · 20th November 2008, 03:50 PM

LOL.

You're up to it RBTCO!

Big breath ...

**robutacion** · 20th November 2008, 04:06 PM

Ok then...!

On the count of 3,
1....................... 2......................

.......................

Cheers

RBTCO

**new_guy90** · 20th November 2008, 07:14 PM

wow thats cool

is that a home made lathe?

**Jim Carroll** · 20th November 2008, 07:18 PM

Originally Posted by new_guy90

wow thats cool

is that a home made lathe?

Have a look here http://www.ubeaut.com.au/woodstuf.htm

**Tim the Timber Turner** · 20th November 2008, 07:37 PM

I see you took the easy way out on this job.

For a real challenge you could have put the drill in the tailstock and spun the post.

Personally I have never been game to try this.

However if you are, I would love to know what happens if it all goes wrong.

Cheers

Tim

Thread: Long hole boring?

Thread Tools

Search Thread

Long hole boring?

Similar Threads

Boring hole for Salt and Pepper Grinders

Post Hole Boring

drilling long hole

Long hole boring

Long hole boring

Tags for this Thread

Posting Permissions