Don't know if anyone else is (like me) concerned about the impact on world blu-tack supplies due to the vast amounts I am using on my Polargraph gondola, but if so here is the answer!

It's a simple 3D-printable mod to add quick release to the standard gondola design that Sandy supplies with his kits. It can be found here http://www.thingiverse.com/thing:31973

Let me know if anyone tries it.

Thanks!

Steve

<edit> Forgot to say thanks to Dealywhopper for the original design, I just re-did it to fit our polargraphs.</edit>

Brill! Glad you like it. I was well impressed to see how quickly you printed one after I uploaded it 🙂 Did it fit the tube ok? My first one was 0.5mm smaller in diameter and I had to file it quite a bit to get a good fit, so I altered it slightly before uploading.
I've also found that if you are doing multi colour drawings as I am, and using the same make of pens in different colours, it makes it easy to get the pen in the same position in the gondola after a swap, improving the position accuracy between the different colours.

Steve

It fit the tube perfectly - a good tight fit, but then I used the oldest version of the file attached to the thing (the first one) - if there's a difference between the two then you might want to specify the difference.

I should also say that my printer isn't necessarily tuned very well, so that might be why the tighter fit tube fit ok. But I'm busy printing off sprockets by the dozen, so I'm already in printing mode and that's why it was so quick!

Is there any issue with the pen not being held firmly enough? I mean because it's held at the far end, rather than at the tip end, it seems like it might wiggle around. I suppose it'd depend on how strong the spring clip is?

cheers! I think this is a real improvement!
sn

Heh, great minds etc. I found the elastic bands really helped cut down on wiggle, and it seems pretty accurate - I'm doing a drawing right now and I'd say the two colours are probably as accurate as my last drawing with the old setup, so it's not looking too bad, but I always like to strive for better 🙂
If I screw up my brass tube (i.e. cut it down and find it doesn't work), can I buy a new length from you?

Steve

Right, latest update:
I have now modified the gondola further, by removing the bearing nearest the drawing surface and shortening the brass tube by 10mm in order to get the clip nearer the pen tip to reduce wiggle/wobble (as discussed above). This did indeed result in the stabilising disc being tilted back off the drawing surface at the top, as predicted, so I reversed the order of the gondola cord arms, flipped one of them by 180 degrees and moved them to the very rear of the bearings, which seems to work, as can be seen in the pic below.
Whether all this has had any material effect on the quality of the drawings, I don't yet know!
At the moment I don't think I'll need a new tube, Sandy 🙂

Ta, Steve