- Thread starter Pete.
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Pete.
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I've checked the motor shaft and both ends have only half a thou TIR but the extension piece has 10 thou plus and it's not such a snug fit on the shaft to hold itself true either. I may make another extension since I don't have any 5/8" bore wheel but I have lods of 1.25", or I may add three jack screws to the extension to see if ican adjust-out the runout.
Pete.
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- Kent, UK
Almost finished with this now. I switched to motor terminals over to delta and dug out a capacitor. Settled on 16uf in the end which gave me a generated leg of 270v. Here's my test set-up.
The cap would only fit up inside the body standing vertically and that would leave the terminals exposed under the base as it stuck out a little. I didn't want a short or anyone getting a shock so I knocked up a Kydex cover from the sheets I got off @bigegg a while back when he was selling them. Kydex is handy for all sorts of stuff and I wish I'd bought more.
Nicely protected here now.
Anyway I wanted to address the problem of the shaft extension running out badly. It slides over the shaft and is secured by a bolt on the end and prevented from slipping by a 2ba dog point grub screw into the shaft keyway. I drilled and tapped for 2 more 2ba screws to make 3 equally spaced around the shaft then did 3 more at the front. Got no pillar drill here now so I knocked up a drilling guide and held the part in my chuck
I turned some copper pads to go under the screws and adjusted the shft for 1 thou runout.
Then I turned a 5/8" to 1.25" adapter from very hard rubber, to centre my wheels properly.I did have some of those plastic bushes you get with grinding wheels but they were very poor and went in the bin.
The rubber adapters work very well indeed. Even before dressing the wheels run smoothly with very little vibration. Here are the wheels mounted.
Not much left to do now just a few small jobs then I'll see how it performs. If I am to use it for sharpening hobs I'll have to make a special arbor for the CBN wheels so that I can adjust the runout more closely as the wheels cannot easily be dressed.
The cap would only fit up inside the body standing vertically and that would leave the terminals exposed under the base as it stuck out a little. I didn't want a short or anyone getting a shock so I knocked up a Kydex cover from the sheets I got off @bigegg a while back when he was selling them. Kydex is handy for all sorts of stuff and I wish I'd bought more.
Nicely protected here now.
Anyway I wanted to address the problem of the shaft extension running out badly. It slides over the shaft and is secured by a bolt on the end and prevented from slipping by a 2ba dog point grub screw into the shaft keyway. I drilled and tapped for 2 more 2ba screws to make 3 equally spaced around the shaft then did 3 more at the front. Got no pillar drill here now so I knocked up a drilling guide and held the part in my chuck
I turned some copper pads to go under the screws and adjusted the shft for 1 thou runout.
Then I turned a 5/8" to 1.25" adapter from very hard rubber, to centre my wheels properly.I did have some of those plastic bushes you get with grinding wheels but they were very poor and went in the bin.
The rubber adapters work very well indeed. Even before dressing the wheels run smoothly with very little vibration. Here are the wheels mounted.
Not much left to do now just a few small jobs then I'll see how it performs. If I am to use it for sharpening hobs I'll have to make a special arbor for the CBN wheels so that I can adjust the runout more closely as the wheels cannot easily be dressed.
bigegg
Scream Not Working Because Space Make Deaf
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- Leeds, West Yorkshire
bigegg
Scream Not Working Because Space Make Deaf
- Messages
- 9,699
- Location
- Leeds, West Yorkshire
you have pm
bigegg
Scream Not Working Because Space Make Deaf
- Messages
- 9,699
- Location
- Leeds, West Yorkshire
i heat it in my workshop "toaster oven" until soft, then press over a pattern between two pieces of plyboard padded with camping mat foam with g-clamps
Seadog
Save the planet. It's the only one with rum!
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Hunt's? Blimey, that's an antique.
Pete.
Member
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- 15,049
- Location
- Kent, UK
Held it under my infra-red lamp for about 20 seconds, then poped it over a 2" diameter chunk of brass and shoved a 3" stub of tube over it, then quickly laid it flat on a cold bench to flatten out the wrinkles. Cut the profile with stanley knife and tin snips.
Pete.
Member
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- 15,049
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- Kent, UK
I did my first meaningful work on this machine today. I have a small pile of annular cutters that need sharpening so I figured it would make a good test of the machine.
The sleeve of the work head has a MT4 taper. I got hold of a number of very cheap MT4 Arbors (thanks to @Milkybars for pointing them out) a while ago so I decided to chop one up to make a holder for the annular cutters.
I had no way to hold this in my lathe except to remove the sleeve from the grinder work head and put it in my 4-jaw. I clockd it in to a tenth TIR, it's well made I can say that as usually you can't clock things in that close as they don't stay perfectly round. Then I parted off the chuck taper, drilled and bored it to accept the annular cutters
Annular cutter fitted. I have to figure out a way to secure it because I cannot drill the sleeve for a grub screw. Wrecked a few bits trying.
I put the sleeve back in the grinder and set up a stop
Lined up the cutter against the wheel by eye.
I went around all ten flutes grinding the outside flank. Grinding annular cutters is a PITA because the manufacturers all use different angles. Generally I grind the inside and outside flanks at 15 degrees with 10-12 begrees back off. Sometimes it comes out great, some types it looks all funky.
Anyway, I am looking for a good condition turret sleeve with MT4 hole so I can cut off the back end and hold it in my 4-jaw to work on both ends of these arbors. If anyone has a lead on one that's not stupid expensive, please let me know.
The sleeve of the work head has a MT4 taper. I got hold of a number of very cheap MT4 Arbors (thanks to @Milkybars for pointing them out) a while ago so I decided to chop one up to make a holder for the annular cutters.
I had no way to hold this in my lathe except to remove the sleeve from the grinder work head and put it in my 4-jaw. I clockd it in to a tenth TIR, it's well made I can say that as usually you can't clock things in that close as they don't stay perfectly round. Then I parted off the chuck taper, drilled and bored it to accept the annular cutters
Annular cutter fitted. I have to figure out a way to secure it because I cannot drill the sleeve for a grub screw. Wrecked a few bits trying.
I put the sleeve back in the grinder and set up a stop
Lined up the cutter against the wheel by eye.
I went around all ten flutes grinding the outside flank. Grinding annular cutters is a PITA because the manufacturers all use different angles. Generally I grind the inside and outside flanks at 15 degrees with 10-12 begrees back off. Sometimes it comes out great, some types it looks all funky.
Anyway, I am looking for a good condition turret sleeve with MT4 hole so I can cut off the back end and hold it in my 4-jaw to work on both ends of these arbors. If anyone has a lead on one that's not stupid expensive, please let me know.
