The Lowspec spectrometer

[SteveBz]

Hi Guys,

I can easily buy threading tools for the small threads, eg M3-M6, but the T2 threads are a bit harder.  How do you get the T2 threads to work (M42x0.75)?

Kind regards,

Steve.

[Thalestris24]

3 minutes ago, SteveBz said:

Hi Guys,

I can easily buy threading tools for the small threads, eg M3-M6, but the T2 threads are a bit harder.  How do you get the T2 threads to work (M42x0.75)?

Kind regards,

Steve.

If you do a search on here you should be able to find instructions for setting up custom threads in Autodesk Fusion 360 if you need to make any from scratch. But aren't you just printing out the existing design? You would  probably have to calibrate the printer to get threads to print out accurately but it's a good idea to do that anyway. There are videos on YouTube for doing that.

Louise

[SteveBz]

1 hour ago, Thalestris24 said:

If you do a search on here you should be able to find instructions for setting up custom threads in Autodesk Fusion 360 if you need to make any from scratch. But aren't you just printing out the existing design? You would  probably have to calibrate the printer to get threads to print out accurately but it's a good idea to do that anyway. There are videos on YouTube for doing that.

Louise

It's just that the threads are very tight.  The female fittings I can just use a Barlow with a T-Thread to clean up the printing.  If I insert and turn with WD40, gradually it cleans up the thread if I repeat for half an hour, but the male fitting doesn't work as well.

Steve.

[Thalestris24]

1 minute ago, SteveBz said:

It's just that the threads are very tight.  The female fittings I can just use a Barlow with a T-Thread to clean up the printing.  If I insert and turn with WD40, gradually it cleans up the thread if I repeat for half an hour, but the male fitting doesn't work as well.

Steve.

I think it's down to printer calibration and maybe printer settings too. FWIW it's something I had a problem with as well. A way around it is to modify the design so that you can fit in place short metal T2 tubes/adapters rather than relying on printing the T2 threads. So just convert threaded part to unthreaded so you can fit and glue an appropriate T2 adapter in place. It's a long time since I printed my old original design lowspec case but I think that's how I got around the problem. It can get very frustrating to have to reprint a whole case (more than once!) just to get the T2 threads right... I'm not sure what the current design is like exactly but if I was printing any kind of substantial case with T2 threads, I'd probably do it in the way that I suggested. It's still worth calibrating the printer properly - x-y movements, filament motion, and accurate levelling, of course! When I printed my lowspec it was the first thing I ever did on a 3D printer. Then began to realise there was quite a steep learning curve for me - so many things to adjust and get right!

Louise  

[saac]

11 minutes ago, SteveBz said:

It's just that the threads are very tight.  The female fittings I can just use a Barlow with a T-Thread to clean up the printing.  If I insert and turn with WD40, gradually it cleans up the thread if I repeat for half an hour, but the male fitting doesn't work as well.

Steve.

Steve I printed the threads out using Paul's Fusion 360 script on the Ender 5. They printed in PLA and standard settings on the printer, they worked fine. Sometimes a sanding of the threads with a fine sandpaper works, I'd also recommend running an ordinary pencil repeatedly over the threads to add lubrication.  Certainly if you have a corresponding thread in metal mate that up and chase the printed thread through a few times. 

[Thalestris24]

Just now, Thalestris24 said:

I think it's down to printer calibration and maybe printer settings too. FWIW it's something I had a problem with as well. A way around it is to modify the design so that you can fit in place short metal T2 tubes/adapters rather than relying on printing the T2 threads. So just convert threaded part to unthreaded so you can fit and glue an appropriate T2 adapter in place. It's a long time since I printed my old original design lowspec case but I think that's how I got around the problem. It can get very frustrating to have to reprint a whole case (more than once!) just to get the T2 threads right... I'm not sure what the current design is like exactly but if I was printing any kind of substantial case with T2 threads, I'd probably do it in the way that I suggested. It's still worth calibrating the printer properly - x-y movements, filament motion, and accurate levelling, of course! When I printed my lowspec it was the first thing I ever did on a 3D printer. Then began to realise there was quite a steep learning curve for me - so many things to adjust and get right!

Louise  

ps something you could try is to heat the metal T2 piece (you are trying to connect) with a hairdryer. When hot it can be easier to screw in. I've only done this with PLA.

[SteveBz]

2 minutes ago, Thalestris24 said:

ps something you could try is to heat the metal T2 piece (you are trying to connect) with a hairdryer. When hot it can be easier to screw in. I've only done this with PLA.

Greast ps!!

[SteveBz]

Hi People,

(My Ender 3 nozzle is blocked - delay while I unblock)

I've been thinking about the camera connection.  I've got a QHY5iii178mm mini with a c-mount connection. Should I put a helical focuser in there, or should I cut a smaller hole, or should I just use a c-mount to T2 thread reducer?

What do you think?

Kind regards

Steve. 

[Thalestris24]

2 hours ago, SteveBz said:

Hi People,

(My Ender 3 nozzle is blocked - delay while I unblock)

I've been thinking about the camera connection.  I've got a QHY5iii178mm mini with a c-mount connection. Should I put a helical focuser in there, or should I cut a smaller hole, or should I just use a c-mount to T2 thread reducer?

What do you think?

Kind regards

Steve. 

Oh dear - PLA is much easier to handle, I think

You will need to focus the camera but maybe only the once (as I recall, but it's a bit foggy now!). However, you'll have to work out beforehand where the camera/sensor will sit so that it's close to the focal plane to start with. Once you've got the approximate distance from the case then you'll be able to work out the best way of fixing it to the case. I'm just using my imagination here. Is there some guidance with the build instructions? I have a GPCAM3-178M and the sensor is quite small so you don't have to worry much about the connection aperture.

Louise

[SteveBz]

1 hour ago, Thalestris24 said:

Oh dear - PLA is much easier to handle, I think

That IS PLA, I haven't started the ABS yet 😅

[SteveBz]

1 hour ago, Thalestris24 said:

GPCAM3-178M

OK, so the same chip.  Is that Toucam?

[Thalestris24]

2 minutes ago, SteveBz said:

That IS PLA, I haven't started the ABS yet 😅

OK - you shouldn't get blocked nozzles with PLA if settings correct...

[Thalestris24]

2 minutes ago, SteveBz said:

OK, so the same chip.  Is that Toucam?

No - Altair Astro

[SteveBz]

Hi Folks, it seems to me that is only element 8 that is affected by the f-number of the scope. Can you tell me how to adjust it for a Meade etx90 (f/13.8)?

Tx.

[SteveBz]

On 27/06/2022 at 12:24, Paul Gerlach said:

Although ABS is a very common filament, it has its problems. Warping due to rapid cooling is a big problem. Especially with relatively big objects like the Lowspec main body.
I Use Green Tec Carbon from Extrudr. It has little warp and is, as the name suggest, filled with carbon.

Paul

Hi Paul,

I bought this, but I'm having serious problems with printing it.  Can I ask you for some tips please?  I have an Ender-3 printer.  Specifically, I'd like to know:

- What temperature do you use on the extruder nozzle?  I'm using 260 C

- What temperature do you use on the bed? I'm using 80C. 

- What nozzle do you use? Mine is stainless steel and 0.4 mm.

- How do you assure adhesion to the bed? I'm using hairspray.

- What settings should I use in Cura?  Eg Support, skirt, raft etc etc etc.

This project isn't for the faint hearted!  3D printing on its own is a new skill!

Thanks

Steve,

[Thalestris24]

2 hours ago, SteveBz said:

Hi Paul,

I bought this, but I'm having serious problems with printing it.  Can I ask you for some tips please?  I have an Ender-3 printer.  Specifically, I'd like to know:

- What temperature do you use on the extruder nozzle?  I'm using 260 C

- What temperature do you use on the bed? I'm using 80C. 

- What nozzle do you use? Mine is stainless steel and 0.4 mm.

- How do you assure adhesion to the bed? I'm using hairspray.

- What settings should I use in Cura?  Eg Support, skirt, raft etc etc etc.

This project isn't for the faint hearted!  3D printing on its own is a new skill!

Thanks

Steve,

Am not sure how often Paul comes on here... Is there any reason you don't want to use PLA or PLA+ or PLA carbon fibre?

The carbon fibre one is supposed to be stronger, stiffer and lighter but prefers a hardened steel nozzle. 

Also, Cura is rather slow - I use Prusa Slicer which I find easy and pretty good https://github.com/prusa3d/PrusaSlicer/releases/tag/version_2.5.0-alpha2

- that's the latest release which I've not tried myself yet. (You just make a folder and 'extract all' into a subfolder then do a 'send to' desktop of the .exe file.

I think the first time you install, you select which printer(s) you are using it for i.e. Ender 3 and configure accordingly

Hth

Louise 

 

Edited July 2, 2022 by Thalestris24

[SteveBz]

2 hours ago, Thalestris24 said:

Is there any reason you don't want to use PLA or PLA+ or PLA carbon fibre?

Hi Louise,

@Paul Gerlach does come from time to time and so he'll probably see this eventually.  He's also following this thread, so if he scrolls back three he'll see my question.

The reason is that he recommended that brand of ABS, so I presume he can tell me what parameters to use.

Kind regards

Steve.

[Thalestris24]

20 minutes ago, SteveBz said:

Hi Louise,

@Paul Gerlach does come from time to time and so he'll probably see this eventually.  He's also following this thread, so if he scrolls back three he'll see my question.

The reason is that he recommended that brand of ABS, so I presume he can tell me what parameters to use.

Kind regards

Steve.

OK, tho I don't see any need for ABS over PLA but it's up to you! I seem to remember (3yrs ago) that Paul had a more sophisticated printer then, at least...

Louise

[skybadger]

I printed mine on an ender 3 using Cura to slice. The body took 3 days to print and a lot of effort to get off the bed afterwards. Didn't do much if anything to Cura to get it working. 80 seems high for pla. I use mine at 60 and make sure I level after its come to temperature.

[Paul Gerlach]

On 02/07/2022 at 10:14, SteveBz said:

Hi Paul,

I bought this, but I'm having serious problems with printing it.  Can I ask you for some tips please?  I have an Ender-3 printer.  Specifically, I'd like to know:

- What temperature do you use on the extruder nozzle?  I'm using 260 C

- What temperature do you use on the bed? I'm using 80C. 

- What nozzle do you use? Mine is stainless steel and 0.4 mm.

- How do you assure adhesion to the bed? I'm using hairspray.

- What settings should I use in Cura?  Eg Support, skirt, raft etc etc etc.

This project isn't for the faint hearted!  3D printing on its own is a new skill!

Thanks

Steve,

Hi Steve,

For some reason I don't receive any e-mail when there are new posts.
Here are some tips:

1. Use a 0.5 mm (or even a 0.6 mm) instead of an 0.4 mm. Due to the carbon fibres a wider nozzle will avoid any clogs.
2. Bed adhesion: Hairspray on PEI surface (without the adhesion maybe to good). Other bed surfaces may also work. Haven't tried that.
3. Bed temperature: 80C first layer, 70C second layer and onwards.
4. Nozzle temperature: 240C
5. For the main body: 6-8 mm brim
6. Layer height 0.2 mm (first layer 0.1 - 0.15 mm)
7. shell: 3 layers
8. infill: 30% Full honeycomb (for main body)
9. Support: not to much infill (20%) and 3-4 layers of interface with a separation of 1 layer (0.2 mm). Support from 50-60 degrees onward.
10. Printing speed: depends on your type of printer (60 - 80 mm/sec). CoreXY printers can handle 120 - 150 mm/sec)

You can print multiple objects but the threatened ones should be printed one at a time at a layer height of 0.1 mm
Calibrating your extruder is essential (google for some explanation) so as to avoid under- or over extrusion.
Because plastics tend to shrink when cooling down, you should use x, y compensation in your slicer. I don't use CURA myself but google for 'Horizontal Expansion CURA' to learn more.

Don't use PLA for the main body as this material is transparent to infrared light and it starts to deform at temperatures above 50C.

Hope this will get you started.

Cheers,
Paul

Edited July 5, 2022 by Paul Gerlach

[SteveBz]

On 02/07/2022 at 14:05, Thalestris24 said:

OK, tho I don't see any need for ABS over PLA but it's up to you! I seem to remember (3yrs ago) that Paul had a more sophisticated printer then, at least...

Back home now 🙂

Paul says PLA is transparent at IR wavelegths that's why he prefers it.

My printer is refusing to do anything at the moment, I need my friend to come over and beat it into submission.

 

[Thalestris24]

17 minutes ago, SteveBz said:

Back home now 🙂

Paul says PLA is transparent at IR wavelegths that's why he prefers it.

My printer is refusing to do anything at the moment, I need my friend to come over and beat it into submission.

 

Hmm... I don't think that IR is an issue, at least it wasn't with the original Lowspec that I printed. Even if it was, I'm sure you could spray or coat the outside with something opaque to IR. What symptoms do you have with the printer?

Louise

[Thalestris24]

1 hour ago, Thalestris24 said:

Hmm... I don't think that IR is an issue, at least it wasn't with the original Lowspec that I printed. Even if it was, I'm sure you could spray or coat the outside with something opaque to IR. What symptoms do you have with the printer?

Louise

The attached paper suggests that black PLA is pretty much opaque to near IR

3D_OpticalTransmittance.pdf

[SteveBz]

On 28/09/2020 at 01:54, Merlin66 said:

I was just wondering, following Valerio's journey into LowSpec spectroscopy, how the others are doing.

There's obviously a few (many?) of the 3D LowSpec instruments "in progress"

Any updates from the members????

Hi Ken,

I've been scrolling through the forum looking for examples. I'm really struggling with the printing on an Ender 3 and I wonder if I should upgrade the printer?   The 2 main problems I gave are firstly it often doesn't finish printing and secondly the pieces don't seem to fit together.  Especially the threaded pieces. 

When I started in astronomy on an eq1,  then an eq3,  then an eq5 then an eq6,  all with a Newtonian,  it wasn't until the eq5,  that I got a decent repeatable experience and the eq6 was just the icing on the cake.  Is the same true of 3d printing? You just can't do it on a cheap printer?

Kind regards,

Steve

[skybadger]

Threads are hard full stop. You have to work out the scaling to manage shrinkage and get the print settings right. 

Why do your prints stop ?

I have an ended 3 and it managed fine but I did cleanup threads on the lathe as well.