Ha! Not Clems.
The banjo is part of a plane blade adjuster that happens to be banjo shaped. The plane was a project started too long ago and the making of its adjuster required the making of a suitable ball turner. Whether the turner I made is the most suitable is questionable especially after viewing Sacc's very much simplified version of the tool.
Basically, the banjo starts off as a 3/4" diameter ball with a 7/32" spigot attached. The spigot is threaded 32 TPI RH, the originals utilised a left hand thread, and the ball itself becomes a ring with a 9/16" through hole that fits the plane blade's cap iron screw.
My first three attempts at making the banjo were failures. The first attempt made it through to the threading stage and as a result of a lack of concentration I turned off the power switch on the lathe instead of disengaging the half nuts. Similar lever, totally different position. I watched the cutter slowly turn its way into the ball.:no:
DSC_4272 (Large).jpg
The other two attempts failed because I moved either the cross or compound slide from their centred position under the ball.
In the end success was achieved by having considerable clearance both sides of the ball. This was a trial and error thing. To create more clearance between the chuck and the ball, I used a saddle stop mounted on the right hand side of the saddle, ensuring that the saddle when moved towards the chuck to cut additional clearance, could be repositioned under the ball centre. Having two saddle stops facilitated a bit of repositioning when it came to cutting the shoulder of the spigot. I used a threading stop on the cross slide to control the depth of cut.
I used and wasted a turned down piece of 40mm 1020 initially and I had rotated it endwise to turn the radius. Not a great idea because the ball ended up being slightly oval in section. The left had tool simply added to my woes.
DSCN1530 (Large).JPG DSCN1532 (Large).JPG DSCN1534 (Large).JPG
The other three attempts were made using 3/4" 1020 bar and a straight tool purchased as a possible means of overcoming some of my positioning problems.
DSC_4259 (Large).jpg DSC_4263 (Large).jpg DSC_4266 (Large).jpg DSC_4270 (Large).jpg DSC_4271 (Large).JPG
To centre the ball for boring on the mill, I just touched a blue Artline mark with an end mill and aligned the spindle with the centring scope.
DSC_4276 (Large).JPG DSC_4280 (Large).jpg DSC_4283 (Large).JPG DSC_4285 (Large).jpg
The finished item, mounted. There are a lot more items to be made so I can't be seen sitting on my hands.:)
DSC_4414 (Large).jpg DSC_4419 (Large).jpg DSC_4417 (Large).jpg
BT
http://ift.tt/1AiEa0d
The banjo is part of a plane blade adjuster that happens to be banjo shaped. The plane was a project started too long ago and the making of its adjuster required the making of a suitable ball turner. Whether the turner I made is the most suitable is questionable especially after viewing Sacc's very much simplified version of the tool.
Basically, the banjo starts off as a 3/4" diameter ball with a 7/32" spigot attached. The spigot is threaded 32 TPI RH, the originals utilised a left hand thread, and the ball itself becomes a ring with a 9/16" through hole that fits the plane blade's cap iron screw.
My first three attempts at making the banjo were failures. The first attempt made it through to the threading stage and as a result of a lack of concentration I turned off the power switch on the lathe instead of disengaging the half nuts. Similar lever, totally different position. I watched the cutter slowly turn its way into the ball.:no:
DSC_4272 (Large).jpg
The other two attempts failed because I moved either the cross or compound slide from their centred position under the ball.
In the end success was achieved by having considerable clearance both sides of the ball. This was a trial and error thing. To create more clearance between the chuck and the ball, I used a saddle stop mounted on the right hand side of the saddle, ensuring that the saddle when moved towards the chuck to cut additional clearance, could be repositioned under the ball centre. Having two saddle stops facilitated a bit of repositioning when it came to cutting the shoulder of the spigot. I used a threading stop on the cross slide to control the depth of cut.
I used and wasted a turned down piece of 40mm 1020 initially and I had rotated it endwise to turn the radius. Not a great idea because the ball ended up being slightly oval in section. The left had tool simply added to my woes.
DSCN1530 (Large).JPG DSCN1532 (Large).JPG DSCN1534 (Large).JPG
The other three attempts were made using 3/4" 1020 bar and a straight tool purchased as a possible means of overcoming some of my positioning problems.
DSC_4259 (Large).jpg DSC_4263 (Large).jpg DSC_4266 (Large).jpg DSC_4270 (Large).jpg DSC_4271 (Large).JPG
To centre the ball for boring on the mill, I just touched a blue Artline mark with an end mill and aligned the spindle with the centring scope.
DSC_4276 (Large).JPG DSC_4280 (Large).jpg DSC_4283 (Large).JPG DSC_4285 (Large).jpg
The finished item, mounted. There are a lot more items to be made so I can't be seen sitting on my hands.:)
DSC_4414 (Large).jpg DSC_4419 (Large).jpg DSC_4417 (Large).jpg
BT
http://ift.tt/1AiEa0d
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