Introduction: Making a Pen Turning Mandrel Kit From Scrap
This tutorial is not about pen turning but how to make your own mandrel kit.
These images show the final assembly and together with a pen turning kit (Streamline Pen). There are many kinds and styles of kits available on eBay and elsewhere.
I could have bought a basic kit including a collet with a morse taper No 2 shank (woodworking lathes) for around Aus$30. I would need a morse taper No3 for my lathes headstock and I already have 3 and 4 jaw chucks for my lathe which will be used to secure and spin the mandrel. You can also buy various sizes of bushings to suit whatever style of pen being made. I have chosen to make FREE bushings out of old bolts etc.
The mandrel also needs a locking nut to tighten the assembled kit for turning against the headstock chuck (to hold the pen blanks securely while turning them down to size).
The mandrel itself needs to be a 6mm round rod that is straight (to not wobble when spinning) and threaded up to around 20mm on one end. Round and perfectly straight steel rods are found in all printers: and old printers are being thrown out regularly when they give trouble.
The components needed are:
1x 6mm round bar - it needs to be perfectly straight. I used a bar from an old discarded Canon inkjet printer.
1x 12mm x 80mm or longer steel bolt - I salvaged mine from something thrown out a year or two ago
1x 25mm round steel rod - Picked up a 300mm one at a local metal industry as scrap - they gave a few sizes to me.
The first image shows the round rods I salvaged from 2 discarded inkjet printers (a Canon and a Brother): the rods are 6mm, 8mm & 10mm. Most cheap printers tend to use 8mm rods and the better quality ones larger and heavier rods. All these rods are great - they are really straight and polished to a fine finish.
The lower rod is a 6mm stainless steel rod that I bought but as I had trouble threading it I decided to use a 6mm rod from the salvaged printers.
The second image is of the 25mm round rod that I got for free as scrap at a local metal works.
The first thing I tackled was the nut that screws onto the tailstock end of the mandrel.
Face off the end of the 25mm round rod and cut off a small length to be used as a nut.
I only needed a tiny length (10mm) off the end of the rod. You can cut this off with an angle grinder or hacksaw. I marked it and cut it through with a hacksaw while spinning it in the lathe.
Put the cut of length back into the 3-jaw chuck and face off the other side.
Now drill the nut through with a 5mm drill bit, then tap a 6mm (M6) thread through it. If you have a knurling attachment it would be a good idea to knurl the outside. I don't have such an attachment (maybe one day)
If you have seen my last Instructable of making a die cutting holder you will know that I tried to thread the end of the 6mm rod by eye using the normal wrench. The thread did not go straight so I cut it off and then made the die holding kit which threaded the end of this rod perfectly.
See my other instructable on how to use this attachment.
All that is left to do once the end of the 6mm rod is threaded is to centre drill the end so it can seat on the tailstock centre.
Now to make the bushings
Here I used an old galvonised 12mm bolt. I cut the head off and centred it in the 4-jaw chuck using a dial gauge to get it accurate. As I was turning one of my bushings down to 10.5mm from 12mm stock I didn't have a lot of material to play with - hence the need to carefully centre the bolt. The 4-jaw chuck can be adjusted for high centre accuracy while the 3-jaw self centering chucks often have a small runout (wobble).
This pen style that I am starting off with (a Streamline Pen) requires 3 bushings.
8.4mm for the 2 outer bushings
10.56mm for the middle bushing. 10.5mm or 10.6mm would be fine.
The centre is drilled out to 6mm so it can slide on the 6mm mandrel.
After hunting around to get the correct sizes for these bushes I came across a great Internet site with all the figures needed for a huge variety of pens in PDF format. These charts have got the details for nearly all pen kits.
A Pen Turners Best Friend
Each of these bushings will be about 10mm long so turn the end of the bolt down to 8.4mm for the 1st 20mm.
Then turn another 10mm down to 10.56mm.
Mark the first section half way (10mm and 10mm), and the second section also at 10mm (closest to the chuck)
Now cut off the bushings starting with the outside first. I used a small hacksaw while the bolt was spinning.
Clean up the bushings. Face them off and then use a fine file to remove the rough edges. You can do this carefully while the lathe is spinning.
Here's the kit assembled and also showing the pen kit parts that will all come together eventually.
Just to show that I have, or am, trying out the kit and the process of turning a pen here are a few images.
I cut two wooden blanks (15mm square) out of some pieces of medium hard wood I have. I centred each in the 4-jaw chuck and bored a 7mm hole through to accommodate the brass tubes from the pen kit.
The tubes are glued into these blanks using super glue and the ends sanded down to the exact edge of the tubes.
As I said earlier, this Instructable is not intended to teach one to make the pens. There are many videos and tutorials on-line.
And here is my first turned down pair of blanks. They still need a lot of fine sanding and finishing off with a hard finish.
I'm very pleased to see that the wood turning tool rest I made is working fine. The length of the rest does need to be a bit longer but I can move it left and right to work both pen blanks.
And here's my first ever pen