The Lowspec spectrometer

[saac]

1 hour ago, SteveBz said:

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

Ken, 

It should be perfectly possible to print on an Ender 3. I printed mine on an Ender 5 which is essentially the same machine and a few others on here have also used an Ender 3 to print their Lowspec.  What do you mean when you say , "it doesn't finish printing" can you show a photograph. It may just be that you are needing to tune your setup on the printer. If you show some photograph of what is happening we may be able to offer some advice. As for fettling parts to get them to fit, that is not unreasonable within limits. 

Jim 

 

Edited August 20, 2022 by saac

[SSI-Rick]

I have successfully printed two complete LowSpec units and two Solex/StarEx units plus spare parts with my Ender 3V2, and found that it was a matter of (painfully) gaining experience with what works and what does not.  I upgraded my printer by replacing the extruder with a 'dual-gear drive" unit($15).  This was the most important upgrade that I made.  I consider it essential. The stock one would slip and not feed filament properly resulting in total failure of the part.   I replaced the Bowden tube with one made of Capricorn PTFE with better heat tolerance.  I tried an 'all metal hotend' and then took it off because it kept clogging.   I installed a BL Touch level sensor for helping with the bed adjustment, but I am not sure that it was really necessary.  I discarded the brass nozzle that came with the printer and used hardened steel of either 0.4 or 0.6 mm diameter.  There have been lots of good suggestions about settings, etc.  I found that PLA with carbon fiber prints very nicely, but there is the concern about thermal stability.  So, I used PETG w Carbon Fiber, and found that a nozzle temperature of 245 to 250 C worked, with a bed temp of 80C.  My printer has the Ender special glass plate on the bed, and I learned that it worked great with no added adhesion helpers as long as it was perfectly clean.  At the start of each print I use isopropyl alcohol to clean the surface.  A level bed with just the slightest distance (a sheet of printer paper can just be dragged without tearing) to the print head is essential for the first layer to adhere properly.  When the part is done, if you let the bed cool down all the way to ambient temperature, it will release from the glass plate completely ... If you try to get it off when the plate is still hot, you will break something trying to get the part off.  The printer must be calibrated as others have said, both in x,y,z dimentsions and for the extruder.  There are YouTube videos that show how to do this.  If all this works out, you grow to love your printer; if not ...

Rick

[skybadger]

I must admit I've been printing rather a lot of things recently of the 12hour or more class but haven't experienced the extruder issues you describe. Much more issues with a poorly spooled reel causing snaps of the feed than anything else.

 

 

[Thalestris24]

My Ender 3 Pro v1 is still going strong! Just over 3 years old now. I had an issue a while ago when the filament was having problems feeding into the extruder. I couldn't figure it out - thought there must be a blockage or something. It turned out that the filament was snagging around the vertical lead screw... I couldn't see the problem from the front. Not sure how it happened - probably because I'd been keeping the filament reel in a zip-lock bag and sat on the bed.  When I returned the spool to its holder, I must have got it snagged. As soon as I re-routed the filament the problem was solved. I still use the brass nozzles with PLA but they do tend to gum up after a while, so I just put a new one on. I do use a teflon insert in the hot end. Occasionally the hot-end inlet nut comes loose. I also noticed a problem with the x-gantry becoming loose - apparently on the right-hand side. However, the fix was to undo the top section, lift the x-gantry off, and tighten the two allen-key bolts which fasten it to the stepper-motor end. I use a metal feeler gauge (0.15) for levelling - nice and precise!  

Louise

ps my hair has mostly turned white now - nothing to do with 3D printing, just old age!

Edited November 7, 2022 by Thalestris24

[saac]

@SteveBz I think there is a great temptation with 3D printers to go into upgrade fever and start replacing everything without being really necessary. I have the Ender 5 which is very similar to the Ender 3, I think it shares all the major components. I think I have had it now for 5 years coming up and the only thing I have replaced was the extruder which was slipping and failing to push the filament through. Everything other than that is stock and it works perfectly. When I have had failed prints it has either been due to my laziness in levelling the bed after a long period of no use or trying to use very old filament (possible too much moisture absorbed or brittle). All problems have been remedied by levelling the bed properly and using decent filament.  I have only once upgraded a component and that was to replace the broken extruder. 

My advice would be start from the basics all over; get the bed levelled, manually will do fine, make sure you are using decent and preferably fresh filament. When you first start a print just double check that the filament is actually feeding through properly, a wee push up the feed tube to assist can help.  Thereafter, just keep monitoring it, decent first few layers are crucial.  Sometimes, if the filament fails to feed through you end up with the head continuing to travel around on its path and the bed lowering but no layers deposited "failure to finish the print". I would double check your extruder and perhaps adjust the tension if necessary to make sure it is gripping and pushing the filament.   The Ender 3 is a sound printer and there is no real need to go upgrade crazy, just get your initial setup tuned in.  Good luck with it. 

Jim 

Edited November 7, 2022 by saac

[SteveBz]

2 hours ago, saac said:

@SteveBz I think there is a great temptation with 3D printers to go into upgrade fever and start replacing everything without being really necessary. I have the Ender 5 which is very similar to the Ender 3, I think it shares all the major components. I think I have had it now for 5 years coming up and the only thing I have replaced was the extruder which was slipping and failing to push the filament through. Everything other than that is stock and it works perfectly. When I have had failed prints it has either been due to my laziness in levelling the bed after a long period of no use or trying to use very old filament (possible too much moisture absorbed or brittle). All problems have been remedied by levelling the bed properly and using decent filament.  I have only once upgraded a component and that was to replace the broken extruder. 

My advice would be start from the basics all over; get the bed levelled, manually will do fine, make sure you are using decent and preferably fresh filament. When you first start a print just double check that the filament is actually feeding through properly, a wee push up the feed tube to assist can help.  Thereafter, just keep monitoring it, decent first few layers are crucial.  Sometimes, if the filament fails to feed through you end up with the head continuing to travel around on its path and the bed lowering but no layers deposited "failure to finish the print". I would double check your extruder and perhaps adjust the tension if necessary to make sure it is gripping and pushing the filament.   The Ender 3 is a sound printer and there is no real need to go upgrade crazy, just get your initial setup tuned in.  Good luck with it. 

Jim 

Hi Jim and others,

Thanks for this feedback.  I'll come back to it in the future.

I have 2 printers the Ender 3, which is really not doing anything now and I don't know why, and an iMakr Startt, which does work, but not well.  The Ender 3 actually belongs to a friend so I can't really do too much damage to it. 

At some stage, I think I'll probably just replace it with a new one that I can pull apart and mess with.  In the meantime, I'm messing with the iMakr, because I can learn how to do 3D printing.  I think that's the main thing.  

I'm currently upgrading the iMakr to a heated bed and that's quite fun because I have to upgrade the firmware too.

This project is running a bit slowly also because I have twins at university and so I can't quite throw money at it in the way I might have . 

I'll try again when my finances are looking a little better.

Kind regards,

Steve.

[SteveBz]

6 hours ago, SSI-Rick said:

I have successfully printed two complete LowSpec units and two Solex/StarEx units plus spare parts with my Ender 3V2, and found that it was a matter of (painfully) gaining experience with what works and what does not.  I upgraded my printer by replacing the extruder with a 'dual-gear drive" unit($15).  This was the most important upgrade that I made.  I consider it essential. The stock one would slip and not feed filament properly resulting in total failure of the part.   I replaced the Bowden tube with one made of Capricorn PTFE with better heat tolerance.  I tried an 'all metal hotend' and then took it off because it kept clogging.   I installed a BL Touch level sensor for helping with the bed adjustment, but I am not sure that it was really necessary.  I discarded the brass nozzle that came with the printer and used hardened steel of either 0.4 or 0.6 mm diameter.  There have been lots of good suggestions about settings, etc.  I found that PLA with carbon fiber prints very nicely, but there is the concern about thermal stability.  So, I used PETG w Carbon Fiber, and found that a nozzle temperature of 245 to 250 C worked, with a bed temp of 80C.  My printer has the Ender special glass plate on the bed, and I learned that it worked great with no added adhesion helpers as long as it was perfectly clean.  At the start of each print I use isopropyl alcohol to clean the surface.  A level bed with just the slightest distance (a sheet of printer paper can just be dragged without tearing) to the print head is essential for the first layer to adhere properly.  When the part is done, if you let the bed cool down all the way to ambient temperature, it will release from the glass plate completely ... If you try to get it off when the plate is still hot, you will break something trying to get the part off.  The printer must be calibrated as others have said, both in x,y,z dimentsions and for the extruder.  There are YouTube videos that show how to do this.  If all this works out, you grow to love your printer; if not ...

Rick

Can I ask, Rick, did you get them both working well?  Do you have any results from them that you can post here, or have posted here?

Kind regards

Steve.

[SSI-Rick]

Dear Steve:

You asked about results and if they are working well.  Coincidentally, I have just returned from the annual conference of the AAVSO in Tucson, AZ, where I gave a presentation on this very topic.  I have attached a pdf version of my PowerPoint slides.  They both perform very well, although it took a lot of effort to learn how to fine tune each of them.  The LowSpec out performs the StarEx within its limits.  The StarEx can accommodate a grating with 2400 L/mm, which will not work in the LowSpec.  With the 2400 grating, the StarEx is theoretically capable of achieving an R value of over 30,000, although I doubt that I could ever actually achieve that.  The LowSpec is a more complicated device to assemble and adjust, and the image in the guide window (using PHD2) is more distorted than it is with the same guide camera and software when using the StarEx.  I think it has to do with the characteristics of the Jeulin slit disc in the LowSpec compared to the reflective properties of the Shelyak slit that I am using in the StarEx, but that is just a guess on my part.  The slit from Shelyak is the same one used in the LHires III and the LISA.

I'm close to being able to routinely produce spectra of a quality sufficient to upload to the various databases: AVSpec, BAA, BeSS, but still working on it.

Rick

Diz_Comparing LowSpec&StarEx.pdf

[skybadger]

Interesting slide set. Thanks. I'd be interested in seeing your spectra. My lowspec has worked well with a 300 lpi grating but I haven't yet tried it with.a 600 lpi.

I commissioned using my vc200l but put it to one side to get my dome automatio complete. What I'd like to do now is run the 12" with the spectrometer and 8" alongside for visual and try to do the impossible - exoplanet spectroscopy. 

[skybadger]

Progress!

Guider focused

Slit optics cleaned and aligned

Collimator focused and focuser calibrated for sensor distance

Camera fitted with rotator for spectrum alignment

So I seem to be ready to go. I'm using a Loadstar as the guide cam using the reflected image but it seems faint and small of field. How do people fair using this image to solve for telescope pointing. Is there ever enough stars or do I need a dedicated second scope to do the pointing ?  

I'd like to automate this under voyager and I see some stuff there, but if I can reliably use the second scope for precision pointing , I can use the primary camera just for spectra, once I have the offsets worked out. 

The primary is a 12" f9 RC, the secondary scope dual mounted is a 140mm Petzval at f8. 

[SteveBz]

Just FYI. In the end I didn't print this myself. It was probably @SSI-Rick and he lent it to me.

Edited June 3, 2023 by SteveBz

[Gasman]

Hi peeps

Forgive me if slightly off topic🤞. I've been out of the astro game for a few years and considering a return. I last was mad keen on spectro, I still have all my gear and have my little Alpy 600 sat quietly on a shelf. As another hobby of mine is 3d printing and wondering if I have anything to gain by printing/using a Lowspec over my Alpy please?. I'll have to dust off my spectro books as I'm a little rusty with it👍.

Thanks

Steve

[SteveBz]

3 minutes ago, Gasman said:

Hi peeps

Forgive me if slightly off topic🤞. I've been out of the astro game for a few years and considering a return. I last was mad keen on spectro, I still have all my gear and have my little Alpy 600 sat quietly on a shelf. As another hobby of mine is 3d printing and wondering if I have anything to gain by printing/using a Lowspec over my Alpy please?. I'll have to dust off my spectro books as I'm a little rusty with it👍.

Thanks

Steve

The Alpy is a nice spectrometer.  I'd get that going first and then try others.  The LowSpec I use is 1800 lpmm and your Alpy is 600.  There's little point in switching unless you want finer resolution.

[Gasman]

Cheers for the quick reply Steve, yes I did wonder that thanks!

Steve

[SteveBz]

8 hours ago, SteveBz said:

The Alpy is a nice spectrometer

I'm just going to add to that, it needs the guide module to keep the star on the slit.

[Gasman]

Yes I used that all the time , impossible to use the Alpy without it. Never bought the calibration module as I found out it just used an Argon/ Neon bulb like those found in a particular starter cap in fluorescent tubes and rigged a jig up for it and it worked a treat.

Steve