Needs Pictures: 0
Picture(s) thanks: 0
Results 1 to 10 of 10
Thread: Best jaws for square blanks?
-
22nd October 2021, 01:09 AM #1
Best jaws for square blanks?
I'm gonna be center drilling a lot of square blanks for various handles and I'm wondering which chuck jaws would be best.
Blanks will be between about 25mm - 42mm, with lengths up to 250mm. I'll be using a Nova G3 chuck.
I'm considering 35mm Spigot Jaws, but I'm wondering if that will be secure enough.
Thoughts?
-
22nd October 2021 01:09 AM # ADSGoogle Adsense Advertisement
- Join Date
- Always
- Location
- Advertising world
- Age
- 2010
- Posts
- Many
-
22nd October 2021, 09:32 AM #2SENIOR MEMBER
- Join Date
- Oct 2010
- Location
- NSW
- Posts
- 652
I always work the other way round. Put a good centre mark in each end, drill chuck in the headstock, hold the blank with my left hand and wind the tailstock in with the right hand.
-
22nd October 2021, 11:21 AM #3Intermediate Member
- Join Date
- Feb 2017
- Location
- Huntsville, AL USA
- Posts
- 32
For a general overview of different jaws for different purposes, you might find this YouTube video from Mike Peace useful:
Chuck Jaws for Woodturners - YouTube
-
22nd October 2021, 11:38 AM #4
Unless I want the squared faces for some purpose, I tend to usually rough out blanks to the round between a morse taper drive centre and a live centre on the tailstock. Marking the centres of the blank first, of course.
Then I secure it in the G3 chuck with whatever suitably sized jaws. Chuck jaws can hold square (or somewhat rectangular) blanks of course, but they hold round better I find, with less movement over the course of turning.
V
-
22nd October 2021, 04:06 PM #5
For handles I don't use a chuck at all. Well I do use a drill chuck in the tailstock. Mark centers, rough to round, mount drill in tailstock. Present drill tip to marked center and crank round by hand to start hole. Then turn on lathe at a slow speed and bore out.
Another way is drill out on drill press while still square then mount between centers using a large cone live center in the tailstock.
Regards
John
-
23rd October 2021, 06:22 PM #6
Yuss, this is pretty much what I've been doing for some time now, but I'm encountering a problem or two with it.
To explain, here's a pic of a few items I'm making:
IMAG4303~01.jpg
They are BDSM canes with FRP shafts. These ones are illustrative of a small, medium and huge size handle.
For the sake of strength and balance, I need to sing the FRP shafts as far into the handle as possible. I'm using either 6mm or 8mm shafts.
What I've been doing is:
-Clamp the blank as straight as possible into the drill press and bore a 6/8mm hole up to 150mm deep. Keeping this consistently straight for the full depth is the problem.
-Then screw a Leg Stud screw into the hole and mount the other end into a Jacobs chuck in the lather headstock. Often I'll use a live center on the tailstock to keep it secure, but because the hole isnt always dead straight I often have the live center off-center.
-After shaping and finishing the handle I remove the Leg Stud screw, fill the hole with epoxy, and slide the FRP shaft into the handle.
As I'm about to get a new Nova chuck, my thought was to try and drill the holes with the lathe instead, and hopefully keeping the hole as dead straight as possible.
-
23rd October 2021, 10:52 PM #7
I predominantly turn renaissance or simple system flutes - just for fun mostly - which obviously consists mostly of a spindle form with a long bore drilled/reamed through it. Really not too dissimilar to your bored handles.
To keep the bore perfectly centred and symetrical in the finished piece it is best to drill the bore first (or after just some rough turning) with quite a bit of extra material for further turning. I use a drill chuck with a morse taper in the tailstock with the lathe set to its lowest speed.
Then once happy with the bore, I remount the workpiece with the live centre in the tailstock pressed against the internal walls of the bore. Splitting from excessive pressure needs to be avoided. Sometimes a wood jamchuck is needed, though not usually. Then the workpiece can be turned until finished.
If you look at my avatar pic you can see a flute joint mounted in just this way.
I hope this helps at all? I might have misunderstood your issue.
V
-
24th October 2021, 01:20 PM #8
It depends on what size the bore needs to be. The narrower the bore, the greater the chance of deflection.
Under ~1cm I'll often use 35mm spigot jaws on my Nova chuck along with a hollow tail spur for support. Then bore the full length through the tailstock, as per for standard lamps. So long as the bore comes out straight enough for the job (there's often some curve, but within limits) I can always take a hand plane and redress the sides of the blank to recentre the ends of the blank around the bore.
For ~1 to 2 cm, I'll bore a 5mm pilot (or appropriate to suit the bit I'll use for the full bore) as above, then mount the jacob's chuck in the headstock and rebore at full size. Pretty much how Picko described in post #2.
Over 2cm I don't worry about the pilot, as the bit is generally thick enough to prevent bore deflection, so I can bore from both ends and be relatively assured they'll meet nicely.
FWIW, I do NOT use spade bits unless I have a suitable sized pilot hole; the narrow shaft almost guarantees deflection and a poor result. Even with a pilot hole, the odds aren't great of success.
- Andy Mc
-
25th October 2021, 08:49 PM #9SENIOR MEMBER
- Join Date
- Aug 2017
- Location
- Canberra
- Posts
- 588
Wood turning obviously isn't your only hobby heffa!
-
25th October 2021, 11:28 PM #10
Similar Threads
-
N.S.W. Turning Blanks, parallel clamps and Hamlet 5 piece set and Nova Chuck Bowl jaws 75mm
By lithro in forum WOODWORK - Tools & MachineryReplies: 4Last Post: 3rd October 2018, 03:50 PM -
Chuck Jaws for Drilling Blanks?
By skot in forum WOODTURNING - PEN TURNINGReplies: 4Last Post: 30th May 2010, 09:07 AM