Gamma Spectrometry Forum

Hi All,

I have been wanting to buy myself a 3D printer for some time, and finally Christopher Lloyd and Elizabeth Lang, who both suggested improvements to the GS-STANDUP have pushed me over the line.

I bought the Anycubic 13 mega, really impressive printer considering the $299 price tag including shipping. It was delivered from a local warehouse and worked straight out of the box (half an hour assembly).
(No affiliation with seller)
After a few test prints, I attempted to print my own plug for the GS-STANDUP, but soon realised that my first design could be improved. With 3D printing it's best when you have a flat surface to print up from, so I made a few changes and came up with the simpler version shown below. I printed a sample in black PLS and it was a perfect fit.

Both Christopher and Elizabeth incorporated nice sample holders to the back of the plug, but I think it is better to print the sample holder separately and attach to the cup after printing (keeping the cup flat, thereby avoiding the support structure).

To complete the plug, I intend to insert a copper and a tin disc, before backfilling with 1.5" of lead shot. Probably a good idea to pour a bit of epoxy glue over the lead shot to stop it rattling around inside.

Once a sample holder is attached to the front of the plug, I predict it will need a cradle to hold the plug horizontal without rolling off the table.
For all my 3D modelling I use Autodesk Fusion 360, have been using it now for a few months and find it really easy to use. (once again, no affiliation)

https://www.autodesk.com/products/fusio ... view#intro

It's easy to design a plug like this, but if anyone wants to print my plug version, the STL files can be downloaded below.
Steven

👍👍

Let me know more off your tests.

I’ve been thinking of getting one for ages - and the price is obviously very good😊

Nice. I built my own 3D printer about 4 years ago (from a kit). Been using it sparsely, not as useful as one might expect but still handy to have in a pinch. As it relates to radiation detection, I printed a while ago a mount for the GS-PREAMP plus Russian boron corona tube, I think I posted the design for that on the forum a year or so ago.

I do most of my modeling in Autodesk's TinkerCAD, because I'm lazy. But since lately I've been trying to get into CNC as well Ive started learning FreeCAD which may be useful for both.

Are you printing in ABS? My favorite material after many experiments is PETG.

FWIW there are laser heads that you can adapt to 3D printers and CNC machines so you can use them for engraving and even cutting wood. Also some plastics. Definitely don't try metal.

stamasd wrote: ↑

14 Jun 2019, 23:06

Are you printing in ABS? My favorite material after many experiments is PETG.

At the moment I am just printing in PLS, but I wan't to try some other materials too. Laser engraving sounds interesting, possibly more useful, but I imagine it would be a bit dangerous without some kind of enclosure.

I think it's going to be useful for prototyping, but since I have a good workshop it's hard to justify a 10 hour print for something I could make in half an hour by hand. Very interesting to learn about the technology though..

Steven

Try PETG filament. It has almost all the good properties of ABS but without the annoying warping problem. Plus it allows you to make translucent objects. The only problem is that it creeps and deforms if it's put under heavy mechanical load.
I have experimented with many types of filament over the years, including POM (polyoxymethylene, aka Delrin). That one is very interesting for making small mechanical parts such as gears etc. because of its strength and low friction coefficient, but it has horrendous warping on printing and is a b*tch to work with. I did find a solution for preventing it from detaching from the print bed prematurely (which it does a lot) but that doesn't help with warping of the upper parts of the object. I wasn't able to correctly print anything larger that 3cm in any direction with POM.
I agree, prototyping and one-off items are the best use of this tech.
I'm currently working on adapting a cheap Chinese CNC for making printed circuit boards by milling copper-clad boards.

Here is a shot of my setup as I am currently running it:
I have started doing my quant analyses of environmental sediment cores to hopefully determine their ages. Once I get a little more data, I will post some of my work.

Also: the black door and red sample rack are PLA and the orange lead-filled standard box is PETG. The door plug does have a sample holder integrated, but it is printed separately and is able to be replaced by screwing it on or off. Very handy for consistent sample and standard placement.

hah...love the lead pig, maybe we can make one in the shape of a pig :D

Steven