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Re: UVEX3 N2

PostPosted: Thu Aug 01, 2019 11:37 pm
by Hamish Barker
Hi James,

I noticed that your thorlab quote includes concave CYLINDRICAL mirrors (CCM254-100-G01). This does not appear to be correct (perhaps you noticed already), I think they should be concave SPHERICAL mirrors (Thorlab part No. CM254-100-GO1). The price is much lower ( USD58 per mirror for CM spherical mirrors, compared to USD 165 per mirror for the cylindrical CCM mirrors).

Presumably it's a lot harder to make a good cylindrical mirror than good old spherical ones.

Hopefully you ordered the right parts (USD 200 saving!).

Cheers,
Hamish

James Foster wrote:Not a question, but for anyone considering this UVEX3 spectrograph's ThorLabs components, the total (without tax/ shipping) comes to $685.60 US. (300 & 1200 l/mm gratings)
Image

When you cost the CCD/CMOS camera, guide camera, and other components (like metric taps, screws, Kapton tape, etc), the cost(s) gets closer to $2.5-3K US.

This is also without the cost of the 3D printed components, so please be sure you have the technical skills/courage and funds before embarking on this project.

James

Re: UVEX3 N2

PostPosted: Tue Aug 06, 2019 5:17 pm
by James Foster
To: Hamish,

RE:"I think they should be concave SPHERICAL mirrors (Thorlab part No. CM254-100-GO1). The price is much lower ( USD58 per mirror for CM spherical mirrors, compared to USD 165 per mirror for the cylindrical CCM mirrors)."

Thanks for catching that! Thankfully, I have not ordered anything. I'm about 2 mouse clicks from getting a Atik 414ex mono for this project as well as a UV clear
window for glass cover replacement. As soon as I know what route to take for the 3D-printing, I'll order the THORLAB parts. Thanks again!

James

Re: UVEX3 N2

PostPosted: Mon Aug 12, 2019 8:54 am
by James Foster
I think I'm going to get this for the replacement (UV clear) cover glass for the Atik 414ex:
https://www.uqgoptics.com/materials_filters_schott_colourless_WG225.aspx
If its cheaper to order more than 2, Let me know if anyone want additional 25.4mm covers and I'll order extra so the
cost can be spread and is less for everyone pursuing this UVEX project sensor.

James

Re: UVEX3 N2

PostPosted: Fri Aug 16, 2019 9:22 pm
by James Foster
I got a quote on these SCOTT WG225 UV transmitting replacement cover glass of $110 USD (90 GBP) each if I buy 2 or $100 USD (80 GBP)
each if buying 5 or more. They are physically 25.4mm round diameter and 1mm thick. Let me know if anybody else is interested in
purchasing these for the UVEX project. I'm ordering them when my Atik 414ex CCD arrives next week.

James

Re: UVEX3 N2

PostPosted: Wed Sep 04, 2019 7:11 am
by Terry Bohlsen
Robin Leadbeater wrote:Hi Terry,

There are details of the "Calibrex" calibration lamp and guider module on the UVEX website, but I did not see the printing files for the box there
http://uvex30.000webhostapp.com/calibrex-par-lopex/

Cheers
Robin


Christian
Any update on this guide module? I would like to print one and see.
I have printed the box for a UVEX but not ordered any parts until I think it is viable for me to do so.
Cheers
Terry

Re: UVEX3 N2

PostPosted: Wed Sep 04, 2019 5:42 pm
by Christian Buil
Hi Terry,

There are 3 prototypes of the guidance module, in test phase. The results seem good. It is necessary to wait a little longer, the parts will be published in not too long (it is a complete set, which covers the optical, mechanical and electronic aspects).

Christian

Re: UVEX3 N2

PostPosted: Wed Sep 04, 2019 11:17 pm
by Terry Bohlsen
Christian Buil wrote:Hi Terry,

There are 3 prototypes of the guidance module, in test phase. The results seem good. It is necessary to wait a little longer, the parts will be published in not too long (it is a complete set, which covers the optical, mechanical and electronic aspects).

Christian

Thanks
Terry

Re: UVEX3 N2

PostPosted: Sat Nov 23, 2019 10:55 am
by Ibrahima
Tom Love wrote:I've just received my printed UVEX parts from a commercial 3D printing and fabrication house (using laser sintering in nylon PA12, which has much better properties than more common nylon 6). It's not a cheap method, but the parts are very, very rigid, with a nice smooth finish. I have difficulty believing that metal parts with realistic dimensions would be very much more rigid. I won't have much time this weekend, so it probably won't be until the following week, but the next task will be to test IR opacity, and then to assemble the optics.

It would be very useful to have a schedule of the specific metal parts (unless I've missed it somewhere) - I can kind of figure them out from the pictures and instructions, but I'm guessing at some of the lengths needed for the hex bolts etc.


Dear Tom.

Do you have, any feedback about IR opacity of nylon PA12 printed parts?

Ibrahima.

Re: UVEX3 N2

PostPosted: Sat Nov 23, 2019 11:21 pm
by Tom Love
Hi Ibrahima,

I used a 275 watt infrared heat lamp at various distances from a CCD camera, which had the uvex cover over its aperture, and tinfoil around the edges to avoid leakage. Then I used an average of five measurements with and without the lamp on at 250mm increments between camera and the heat lamp, from 500 to 1500mm. The attached graph shows the excess counts at each distance when the lamp was on. It's not quite a square relationship because the radiation from the lamp is focussed into a beam by the lamp, which has a silvered rear.

Once you get to distances over about 1m the excess counts due to the lamp are down to under 40 adu.

My conclusion was that since there is highly unlikely to be an IR emitter within a couple of orders of magnitude of the power of the heat lamp near my setup when in use, at this level of transmission IR leakage is unlikely to be an issue. Though if I thought there was a problem I would make a tinfoil cover for the UVEX.

Re: UVEX3 N2

PostPosted: Sun Nov 24, 2019 11:00 pm
by Ibrahima
Hi Tom.

Thanks for the test and feedback. The results you obtain are very encouraging. I guess that you have used small exposure time for your measurements.
Would the ADU excess limit (35 ADU in your test) be larger if you consider long exposure times (300 sec or 600 sec) as we usually do in spectro? Or is it possible that, from a distance of 1.25m to the spectro, the ADU excess is only due to the thermal behaviour proper to the camera?

Best regards,
Ibrahima.