Wednesday 29 January 2014

# Shop Stool Build Off.. Part 3. Day two (Sunday)


A bit of a late start today, got into the workshop around 9 am.. later than I wanted, but I had time to think about what was sorted, and what I needed to get done.
The first thing to do was to get the joints of the boss' all done and get them glued up to the legs. I had already got two done, so only four more to do. But there was one thing that I needed to check out..

I knew that I couldn't just put two boss's any old distance apart..they were both going to be joined by the threaded spindle. So when the positions were marked on the legs I had to ensure that the boss' were on the threaded spindle then around the correct distance apart. I chose around 125 mm, this is 25 mm more than an Ikea piano stool shown in Part 1. I wanted this extra 25 mm so that the threaded spindle would have less play, one of the issues with that stool..

So then I just had to mark on each leg from a datum already taken from the former. I'm sure engineers know what I'm up to and there's probably all sorts of theory and practice stuff behind it. But what I do know, is that if I hadn't done this, then I would have been in all sorts of trouble..


Here you can see my last 'dry fit'


Each leg could now be bonded into the boss' and I chose to do them one at a time. with a couple of shop made jigs..

Next.. to turn the spindle for the threaded part.. and it started  really well. I turned the old Beech table leg down to 32 mm (11/4"), took it off the lathe cut some thread, then put it back on the lathe if it needed just a little more off, which it did on a couple of occasions. But the 'fun' started half way down, I hit a patch of knots, only very small, tiny in fact..but it was enough to start the grain ripping out..after that I couldn't get it back on track...so now all I could do was use my sample piece that was being used for cramping up the legs and boss'.. I did expect problems.. but not with the things I've done lots of times before... oh well.

This meant that I could get on with turning the seat.

I had two choices with the seat, Sweet Chestnut that would compliment the White Oak or..A turning blank of Purpleheart that I had had for over 20 years, that I've been hanging on to until the time was right.. The sweet Chestnut was over 2" thick and I didn't want to waste just under half of this thickness.. whereas the Purpleheart was the correct diameter and thickness, even with Its couple of flaws. So onto the lathe it went...I didn't take much off, just rounded the edges and dished the top to around 6 mm (1/4"). That was enough.

Then it was just a case of getting the top boss, (made the day before) fixing it to the underside of the seat with three lovely old GKN  11/4" countersunk slotted screws. After assembling all the parts I gave it a coat of Danish Oil with an extra additive that accelerates the drying.



And here we have my stool.

It was fun at times, quiet stressful. The de-lamination was a pain and I now know why it happened, and would build my new understanding of why into my process of laminating, I'll try it out and if it makes all the difference then It was a great lesson learnt.

Gluing up seventeen strips in one go was mad, I did expect the de-lam to be much worse than it was, so I wasn't far off.

The threading..I'll have to look into it. But the tap box isn't very happy..after hitting those knots, might just be a sharpen up.


Contrasting colours look great..

There will be a Part 4..look out for it..there may even be parts 5,6 and 7..but for the minute..

I'm done

Hope you enjoyed

All the best

Jamie

4 comments:

Jeremy said...

Great work here love the elliptical section...Dang I thought I had a shot...

Jamie said...

Thank you..It was fun, some might think it too much, but I think we should always push ourselves. The feedback from visitors so far has been encouraging..So job done, anything else would be a bonus..

All the best

Jamie

Mario said...

Certainly did enjoy it, what a beautiful and functional stool. Can't say 'well done' enough :-)

well done, well done, well - you get the idea!

Jamie said...

Thank you..