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View Full Version : Need to bore a big a hole and not enough swing on lathe



cuemaker
10-15-2011, 10:04 PM
I need to bore out a hole on a 12" flywheel when my lathe has only a 10" swing....

I need to bore out to 1 5/8 and I dont have a drill bit that big.

I have a drill press that is stout enough, but I dont have a boring head to help me out.

Is the answer I need to buy a boring head and use the drill press or find a friend with a big lathe? Or even buy the proper sized drill bit which is the more expensive option other than buying a bigger lathe or mill.

Toolguy
10-15-2011, 10:09 PM
On a hole that big, probably with a keyway, you need to find someone with a bigger lathe and a big boring bar or a mill and a boring head. That is not something a giant drill bit is likely to do well.

Boostinjdm
10-15-2011, 10:10 PM
Have you asked at your local machine shop? Might not be as expensive as you think.

RancherBill
10-15-2011, 10:13 PM
My head is blank tonight, but, I remember somebody made a line boring unit. It was based on a design by Sir John MBE. It was based on using 2 sets of sprockets to make the boring bar rotate faster than the bar was advancing. IIRC it was powered by a half inch drill.

Maybe this rings a bell and someone could post a link to the thread.


I found IT!!!!
http://bbs.homeshopmachinist.net/showthread.php?t=41662&highlight=boring+bar

Pherdie
10-15-2011, 10:23 PM
Assuming the hole you wish to bore in your flywheel is independent in alignment in relation to your flywheel (just a clearance hole), you could bore it on your drill press. Even if alignment to the flywheel was critical, you could do it, but that's another story full of measurements, adjustments and drama due to multiple axis's and flex on most drill press tables.

Make yourself a poor man's boring bar. Get some drill rod, max diameter your drill chuck can handle (minimal flex), cross bore the rod for a tool bit and a set screw to keep the bit fixed. Do a search, lots out there on homemade boring bars.

Good luck.

Fred

cuemaker
10-15-2011, 10:28 PM
Assuming the hole you wish to bore in your flywheel is independent in alignment in relation to your flywheel (just a clearance hole), you could bore it on your drill press. Even if alignment to the flywheel was critical, you could do it, but that's another story full of measurements, adjustments and drama due to multiple axis's and flex on most drill press tables.

Make yourself a poor man's boring bar. Get some drill rod, max diameter your drill chuck can handle (minimal flex), cross bore the rod for a tool bit and a set screw to keep the bit fixed. Do a search, lots out there on homemade boring bars.

Good luck.

Fred


I was just working up to this in my head, while watching tv with kid (giant worms or some such thing)..
As for alignment, thats something else I have to give thought to

firbikrhd1
10-15-2011, 10:48 PM
Get one of these:
http://i283.photobucket.com/albums/kk287/firbikrhd1/P5030010.jpg

Otherwise, if memory serves correctly, the 10" lathe shown actually has a bit more than 5" from center to the ways. I'm not certain if your lathe is similar but if so you may be able to mount the flywheel to the carriage (on an angle plate maybe), make a boring bar to be driven by the chuck and bore that way. It just depends on the dimensions of your machine.

Don Young
10-15-2011, 10:57 PM
Get one of these:
http://i283.photobucket.com/albums/kk287/firbikrhd1/P5030010.jpg

Otherwise, if memory serves correctly, the 10" lathe shown actually has a bit more than 5" from center to the ways. I'm not certain if your lathe is similar but if so you may be able to mount the flywheel to the carriage (on an angle plate maybe), make a boring bar to be driven by the chuck and bore that way. It just depends on the dimensions of your machine.

Now that's a handy accessory!

gwilson
10-15-2011, 11:11 PM
What other machines do you have? It can be done with a horizontal mill. Fasten the flywheel to the arbor. Mount the cutter on the table,and bore.

philbur
10-16-2011, 03:36 AM
You can't use a boring head in a drill press, there is no way to retain the taper in the spindle. The taper will fall out due to the lateral forces (wiggling) at the cutting tip.

Find a freind with a bigger lathe.

Phil:)

jugs
10-16-2011, 03:53 AM
What other machines do you have? It can be done with a horizontal mill. Fasten the flywheel to the arbor. Mount the cutter on the table,and bore.

Or on a vertical mill, mount work on rotary table & use large dia (to reduce flexing) long series mill.

But best find a friend with a big one................ ( lathe):D

camdigger
10-16-2011, 04:59 AM
1. Google super drill. I've mentioned them here before. They work in a drill press and have adjustable hole sizes from 1/2" to 2 1/2" Most snobbish machinists laugh at them, but for clearance hole class work, they can't be beat for effectiveness and economy.
2. Line boring setup. There have been several versions discussed here and elsewhere. My preference would be something with a manual feed for simplicity - little more than a pair of pillow block bearings for the bar and a feed screw set up on the end of the bar and a hand drill to drive the other end.
3. linebore setup in drill press similar to #2,but driven and feed by the drill press.

krutch
10-18-2011, 03:52 PM
Could get spade drill. I have an interchangeble blade type with which a 1" hole is first drilled then followed by the spade drill. The blade holder uses the 1" hole as a pilot and the blades come in various sizes. You did not mention, or I didn't notice your hole finish. I used my tool to open a hole in some 10+" diameter by 3" thick steel on my mill before I finished on the lathe to 2+" for a Caterpiller bearing tool. Worked pretty well. Finish was not too important on the drilled hole, but comes out fairly good if ya don't push through too fast. Must use coolant flood and get messy. Been more than ten years since I did this job, but the tool sure was handy.

Henro
10-18-2011, 08:19 PM
If the ID is not critical...why not just use a hole saw? 1& 5/8" is a common size...cuts much easier than a drill...

Just an idea that I did not seem mentioned above. Would work with the drill press...

Not sure about the thickness...but I think an inch depth (or more) would be feasible. If more is needed, drill the pilot hole first and then go half from each side...

Evan
10-18-2011, 09:15 PM
Depending on your lathe it may be possible to raise the head stock. Raising it an inch won't make much difference to rigidity and for this job you don't need the tailstock. On a South Bend the headstock is simply clamped to the ways by a couple of bolts under the ways. Making a riser is relatively simple and the headstock is self aligning when replaced to normal height.

Bill McLeod
10-18-2011, 09:38 PM
this guy will sell you an annualr cutter 1 5/8 for $30.90 Cdn. I have a bunch and they are fine.

http://www.accusizetools.ca/

jkilroy
10-18-2011, 09:53 PM
I will second the annular cutter, been using a lot of them recently, they work great. Holes are to size and with a fantastic finish, almost ground.