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Calibration Boards

Posted: 25 Jan 2017, 01:04
by fritts
Wondering if anyone has used a service like the one at the link below for making their calibration panels on aluminum. I have the polyboard David calibration files and though fairly sturdy have question printing some that might be a bit more accurate.

http://www.zno.com/metal-print.html

Re: Calibration Boards

Posted: 31 Jan 2017, 00:01
by avogra
I'm not yet long enough in the whole David business, but didn't David make the first calibration panels out of Dibond? Or is that something different? Yet I think nothing beats the current design with glass panels. I suppose any metal will bend a slight amount when there is something attached on only one side.

Re: Calibration Boards

Posted: 26 Jan 2018, 21:50
by lovebay1
My selfmade calibration board, support is 3dprinted and designed by me.
Now I'm waiting courier for my projector...
20180126_223915.jpg
20180126_224005.jpg

Re: Calibration Boards

Posted: 29 Jan 2018, 18:00
by Alonso
They look nice lovebay! What are the panels made out of?

Re: Calibration Boards

Posted: 29 Jan 2018, 18:48
by lovebay1
Thanks Alonso, it is made with adhesive printing on forex 5mm.
Then i designed white 90 degree plastic support and 3d printed.

Re: Calibration Boards

Posted: 13 Mar 2018, 02:46
by Micr0
fritts wrote:
25 Jan 2017, 01:04
Wondering if anyone has used a service like the one at the link below for making their calibration panels on aluminum. I have the polyboard David calibration files and though fairly sturdy have question printing some that might be a bit more accurate.

http://www.zno.com/metal-print.html
Old Thread but I just had a set of 350mm panels made via a similar process. I will be testing them for accuracy and see how they work in the next week or so. will report back. one problem I already see is that the edge definition (the printed edge) isn't great. you can clearly see the pixelation of the printing. more later.

Re: Calibration Boards

Posted: 17 Jun 2018, 07:07
by martan
Thread lift :-)

I made angles in my milling machine to be certain of the 90-degree angle. (Tried 3D-printed but not good enough. Measuered at work.)
Then called the local glass shop (glazier?) and ordered two pieces of ordinary 3mm window glass.
It cost me SEK 50 (about 5 Euros).

Glued the glass into the angles with silicone.
Printed the A4 Calibration left/right printouts on Polyester (Avery/Zweckform L4775) in my cheap home laser printer.
(Ordinary paper is moist sensitive and hard to mount/align.
Polyester is mounted with a drop of soap and water and can be easily aligned to each other)

Scale 145 mm.

This panel calibrates easily to RMS < 0,2 on both cameras.

Some pictures. The 40 scans (!) and the fused result (Vertex spacing 0,16mm, Sharpness 0). Carburettor test object as always :-)

Re: Calibration Boards

Posted: 20 Jun 2018, 18:36
by Micr0
martan wrote:
17 Jun 2018, 07:07
Thread lift :-)

I made angles in my milling machine to be certain of the 90-degree angle. (Tried 3D-printed but not good enough. Measuered at work.)
Then called the local glass shop (glazier?) and ordered two pieces of ordinary 3mm window glass.
It cost me SEK 50 (about 5 Euros).

Glued the glass into the angles with silicone.
Printed the A4 Calibration left/right printouts on Polyester (Avery/Zweckform L4775) in my cheap home laser printer.
(Ordinary paper is moist sensitive and hard to mount/align.
Polyester is mounted with a drop of soap and water and can be easily aligned to each other)

Scale 145 mm.

This panel calibrates easily to RMS < 0,2 on both cameras.

Some pictures. The 40 scans (!) and the fused result (Vertex spacing 0,16mm, Sharpness 0). Carburettor test object as always :-)
Very good so far. Have you measured the accuracy of you CNC?

The reason I ask is that milling the dot pattern on a good CNC will be far more accurate than printing them. I have found that even a good, new laser printer can produce a fairly significant amount of error. The milled calibration patterns I made produce calibrations with RMS errors well below .2 with .09 being the best I've gotten. My typical is around .13. With this my alignments are excellent and actually much faster then with higher error numbers.

Re: Calibration Boards

Posted: 21 Jun 2018, 06:21
by martan
µ and all,

I havn't measured the machine itself (Old fashion Aciera F3) but it is the most acurate
I (or my friends) have. I checked the finished panel with a calibrated (OK!) "angle hook".
and i seems very acurate. I think we have a nice digital angle guage at work and maybe
I try this one some day.

I have DRO (digital readout) on the milling machine and it would be fun to try your method.
Unfortunately my milling machine is quite small and I think the Y-axis is about 135mm so only
small panels are possible. Can you point me to a forum thread where you show your method?

I share your experience with the aligning - it is very fast when RMS values are low.

Re: Calibration Boards

Posted: 21 Jun 2018, 16:39
by martan
Again,

Received the original HP-panels today. First try att the 120mm scale.
The 6 big circles seems much bigger than the prinouts, Is this a factor in getting these (see picture)
error values?