Skie_M
Member
A quick tutorial for how to go about building a quick and dirty off-center lathe sanding attachment...
You will need various tools ... obviously, a working lathe too!
A Drill Press (required for this little attachment to be built properly, if you don't have one, borrow one ... the required step is very quick and easy!)
7mm Drill Bit
Drill Chuck (for your tailstock, to hold the finished jig)
Face Plate (with scrap OSB or hard countertop substrate ... or a decent hardwood. Turn it round, face it off, finish it, and apply sandpaper to the flat surface.)
Spare Mandrel (or 1/4" aluminum or brass rod, cut down to manageable lengths and sanded down to match exact mandrel size) and a working pen mandrel for turning the jig, IF YOU WANT IT TO LOOK ROUND AND NEAT.
Scrap OSB or other countertop material substrate ... solid corian would be ideal, but let's not waste awesome pen material! Make this 4" x 4" x 2" ... You could go larger if you wish.
Spare 7mm brass tube barrels (however many you wish to use up ... this jig should last forever with decent care!)
First, make sure your blank is glued up if it needs it and has had time to cure fully.
Next ... drill press! Use the 7mm bit to drill a hole in the center (doesn't have to be exact, just get it close, though exact would speed things up a tiny bit). WITHOUT CHANGING ANYTHING AT THE DRILL PRESS, keep the blank oriented in the EXACT SAME DIRECTION and drill multiple OTHER HOLES with the same 7mm drill bit. Make them in a random pattern, space them out enough that you can easily reach them to put your mandrel rods and trimming sleeves and blanks on them without interference.. The idea is to have them exactly parallel with the central hole. The drill press table DOES NOT HAVE TO BE EXACTLY LEVEL.
On to the next step ... You don't have to turn it if you dont mind it looking a bit raggedy ... but hey, you have a lathe, the tools, why not get in some practice? Glue a 7mm pen barrel into the central hole ... use your preferred method, and then trim the barrel flush to the surface of the blank. Ream the barrel and mount it on your pen mandrel. You can use an old spare, as long as it's straight. Turn it round and true up the faces to make it pretty... remember, all those holes you drilled should be EXACTLY PARALLEL to the central hole you are turning on... so you'll be able to use any of them to position a pen blank for sanding.
Don't forget to apply sanding sealer and a CA finish ... you DO NOT want your jig absorbing moisture and warping or falling apart on you ... protect it! Every single extra hole through the jig should now be glued up to have it's own 7MM brass barrel. I made mine with 5 extra holes, so I used up 5 spare pen barrels. (I had 12 laying around... I ordered extras to make small jigs and beads.)
Take your spare mandrel and cut 4 or 5 inches off (whatever you're comfortable working with). You only need enough to securely fasten all the way into the back of your drill chuck and up through the central hole of your sanding jig. Any extra sticking out the front won't do a whole lot, unless you really want to sand in the very center of your sanding disc, which will wear that part out very fast. Secure this section of mandrel (or it's substitute rod) inside the center hole at your ideal position.
Secure additional sections of mandrel into each of your extra holes ... you want them fully seated inside the body of the jig, and extending far enough out to give you perfectly perpendicular support for your entire pen blank ... I would say 4 inches, and with 2 inches inside the jig body that should be 6 inches per mandrel section.
Now ... with the sanding disc attached to the headstock, and a drill chuck holding the sanding jig to the tailstock, every single rod should be able to present a pen blank at a perfectly perpendicular arrangement to the sanding disc for a perfectly sanded blank every time!
You will need various tools ... obviously, a working lathe too!
A Drill Press (required for this little attachment to be built properly, if you don't have one, borrow one ... the required step is very quick and easy!)
7mm Drill Bit
Drill Chuck (for your tailstock, to hold the finished jig)
Face Plate (with scrap OSB or hard countertop substrate ... or a decent hardwood. Turn it round, face it off, finish it, and apply sandpaper to the flat surface.)
Spare Mandrel (or 1/4" aluminum or brass rod, cut down to manageable lengths and sanded down to match exact mandrel size) and a working pen mandrel for turning the jig, IF YOU WANT IT TO LOOK ROUND AND NEAT.
Scrap OSB or other countertop material substrate ... solid corian would be ideal, but let's not waste awesome pen material! Make this 4" x 4" x 2" ... You could go larger if you wish.
Spare 7mm brass tube barrels (however many you wish to use up ... this jig should last forever with decent care!)
First, make sure your blank is glued up if it needs it and has had time to cure fully.
Next ... drill press! Use the 7mm bit to drill a hole in the center (doesn't have to be exact, just get it close, though exact would speed things up a tiny bit). WITHOUT CHANGING ANYTHING AT THE DRILL PRESS, keep the blank oriented in the EXACT SAME DIRECTION and drill multiple OTHER HOLES with the same 7mm drill bit. Make them in a random pattern, space them out enough that you can easily reach them to put your mandrel rods and trimming sleeves and blanks on them without interference.. The idea is to have them exactly parallel with the central hole. The drill press table DOES NOT HAVE TO BE EXACTLY LEVEL.
On to the next step ... You don't have to turn it if you dont mind it looking a bit raggedy ... but hey, you have a lathe, the tools, why not get in some practice? Glue a 7mm pen barrel into the central hole ... use your preferred method, and then trim the barrel flush to the surface of the blank. Ream the barrel and mount it on your pen mandrel. You can use an old spare, as long as it's straight.
Turn it round and true up the faces to make it pretty... remember, all those holes you drilled should be EXACTLY PARALLEL to the central hole you are turning on... so you'll be able to use any of them to position a pen blank for sanding.Don't forget to apply sanding sealer and a CA finish ... you DO NOT want your jig absorbing moisture and warping or falling apart on you ... protect it! Every single extra hole through the jig should now be glued up to have it's own 7MM brass barrel. I made mine with 5 extra holes, so I used up 5 spare pen barrels. (I had 12 laying around... I ordered extras to make small jigs and beads.)
Take your spare mandrel and cut 4 or 5 inches off (whatever you're comfortable working with). You only need enough to securely fasten all the way into the back of your drill chuck and up through the central hole of your sanding jig. Any extra sticking out the front won't do a whole lot, unless you really want to sand in the very center of your sanding disc, which will wear that part out very fast. Secure this section of mandrel (or it's substitute rod) inside the center hole at your ideal position.
Secure additional sections of mandrel into each of your extra holes ... you want them fully seated inside the body of the jig, and extending far enough out to give you perfectly perpendicular support for your entire pen blank ... I would say 4 inches, and with 2 inches inside the jig body that should be 6 inches per mandrel section.
Now ... with the sanding disc attached to the headstock, and a drill chuck holding the sanding jig to the tailstock, every single rod should be able to present a pen blank at a perfectly perpendicular arrangement to the sanding disc for a perfectly sanded blank every time!