Build a shutter tester for Focal Plane shutters - Cheap, Easy & it Works

ic-racer · Mar 22, 2023

Xylo said:
But I made it with a removable sensor like on the commercial machines and I regret doing so a bit. Thing is that the commercial ones used in repair shops have a light that is collimated. This makes the readings much more precise.

Inexpensive laser used in these projects makes collimated light as good or better than the older commercial testing units. As long as the sensor is interpreting the on/off correctly, a laser/Arduino shutter tester can be better than the commercial units in my opinion.

I bid up to $600 for this ZTS tester on e-bay a few months ago; now I'm glad I did not get it. For $600 I can make a very very nice one myself.

Xylo · Mar 22, 2023

I'm totally with you on that one.
One thing that never ceases to amaze me is how good the stuff you can make with a microcontroller is when compared to commercial units from decades ago.

Flighter · Mar 25, 2023

It lives…

...but I think I need to invest in a hot glue gun to stick the lasers and receivers onto the stand as my bright idea of using blu-tack isn't working as my connecting wires are quite stiff and this causes the lasers and receivers to slowly move out of alignment. Some thinner hookup wire would have been better than the thicker wire that I had lying around.

Xylo · Mar 25, 2023

I would be tempted to cut-out two slots in the wood to set the boards in the channels.
As for the lasers, I'd use the mounting holes in the boards and put tiny screws in there..

pemcg · Mar 27, 2023

A word of warning to anyone trying this, if you detect a burning smell after wiring it up and powering on, you may have inserted the 3 legs of the laser receiver in the wrong way around :-(

Xylo · Mar 27, 2023

pemcg said:
if you detect a burning smell after wiring it up and powering on, you may have inserted the 3 legs of the laser receiver in the wrong way around

It's also called "that magical blue smoke"

pemcg · Mar 27, 2023

Xylo said:
It's also called "that magical blue smoke"

Yes, having waited a couple of weeks for the parts to arrive, it was also a multi-expletive moment. At least I assume that was the cause of the burning smell. I had certainly put the receiver legs in the wrong way round, and the program doesn't print anything other than "ready" on the com output, so I'm guessing it's not getting the interrupts from the receivers (even now that I've turned them around the right way).

Niglyn · Mar 27, 2023

Flighter said:
It lives…

View attachment 333575

...but I think I need to invest in a hot glue gun to stick the lasers and receivers onto the stand as my bright idea of using blu-tack isn't working as my connecting wires are quite stiff and this causes the lasers and receivers to slowly move out of alignment. Some thinner hookup wire would have been better than the thicker wire that I had lying around.

Yay, gives me a bit of a buzz to see my design has been built by somebody )
A hot glue gun is a great tool, handy for jobs around the house. Aldi/Lidl often have a pack of glue sticks in their Thursday middle isle.

Niglyn · Mar 27, 2023

Xylo said:
I would be tempted to cut-out two slots in the wood to set the boards in the channels.
As for the lasers, I'd use the mounting holes in the boards and put tiny screws in there..

There is another almost identical tester and the builder drilled holes in the wooden upright to put the laser tx in, rather than gluing to the top. Some boards have the laser attached just by its wires, others have the brass body also solderd to the board. Mine was loose, so got the hot-glue treatment )

Niglyn · Mar 27, 2023

pemcg said:
A word of warning to anyone trying this, if you detect a burning smell after wiring it up and powering on, you may have inserted the 3 legs of the laser receiver in the wrong way around :-(

Oh no ( sorry to hear that.

The little bubble on the front of the rx sensor has to point towards the header pins on the board.

Niglyn · Mar 27, 2023

pemcg said:
Yes, having waited a couple of weeks for the parts to arrive, it was also a multi-expletive moment. At least I assume that was the cause of the burning smell. I had certainly put the receiver legs in the wrong way round, and the program doesn't print anything other than "ready" on the com output, so I'm guessing it's not getting the interrupts from the receivers (even now that I've turned them around the right way).

Really sorry, yes, you would have murdered your photo-transistors.
If you touch the centre wire of the rx (which goes to Arduino pin 2) to the ground connection, this should trigger the Arduino.

Niglyn · Mar 27, 2023

The little dome lens on the photo-transistor must face forward towards the header pins.

Niglyn · Mar 27, 2023

This is the way they go in, legs numbered here are the same as in the picture above with the photo-transistor in the board.
There is a prize for anybody who can find a source for these components on their own. (pemcg needs a couple) and the next version (complex shutter tester that works) requires six.

Niglyn · Mar 27, 2023

Xylo said:
I'm totally with you on that one.
One thing that never ceases to amaze me is how good the stuff you can make with a microcontroller is when compared to commercial units from decades ago.

Modern microcontrollers do allow us tinkerers to make things, that would have been too complex using discrete components and logic chips a few years ago. Having the microcontroller mounted on a board, with power regulator & USB socket & USB to TTL converter, is so useful.

I bought, from HiViz, his cameras multitrigger & splash controller that used 555 timers. It took inputs from sound or light & then after a delay would fire the flash or operate solenoids to drop water. This enabled freeze frame photos.

This worked well, but without a digital display, it was difficult to set up to previous settings. A simple Arduino program (sketch) was all that was required to sample the delay & display it on the LCD. I did offer it to the seller, all free, but nothing came of it. So if you have any of his products, you are welcome to the code.

Needless to say, I then went on to build my own from scratch using an Arduio Mega. It became a bit of a hardware and software monster, so not really suitable for distribution or another build it thread.

snusmumriken · Mar 27, 2023

Nigel, I am going to build the device as described in this thread. But just to be forewarned, what is the expected advantage of the 6-laser complex shutter tester that you mentioned above?

Niglyn · Mar 27, 2023

snusmumriken said:
Nigel, I am going to build the device as described in this thread. But just to be forewarned, what is the expected advantage of the 6-laser complex shutter tester that you mentioned above?

I can't think of any advantages, just more complexity )

Two sensors for horizontal shutters, with a spacing of 32mm. Two sensors for vertical shutters with a spacing of 20mm and two sensors to detect shutter bounce.

ic-racer · Mar 27, 2023

FYI on the sensor modules.

Seems the manufacturer updated the sensor parts from SIC553-04 to PIC0103SL and PIC0903SL so the sensor one buys may have OPPOSITE light response than the original Niglyn is presenting. On another forum they compared the datasheets, and, other than the reverse response, the other parameters are the same.

I actually found this out myself because the sensors in the virtual model I built was modeled from the older sensor and the response was opposite, so I had to tweak the original code.

ic-racer · Mar 27, 2023

I noticed on my virtual model the C1 and C2 results are huge numbers; 6 digits. I did not mention it because Niglyn never indicated the code would work on a virtual model. However, I see Flighter's model above has the same output. Is that correct?

Flighter · Mar 27, 2023

I don't think so, I've been getting results that I don't really understand but haven't had time to investigate, camera was an OM1 set at 1/500 second.

The following screenshot was taken of the serial monitor window in the Arduino IDE [Tools > Serial Monitor].

Although the blu-tack seemed to firm up after a day I'm still finding I'm getting a slow drift off alignment and think Xylo's thoughts on securing the lasers and receivers are a good idea. In particular I'm wondering if the Shutter2 star time of 0 results from misalignment. I'm puzzled by the weird milliseconds figure that appears at times and which bears no relationship to the microseconds figure. Hopefully I can get time next weekend to have another go.

Other than ensuring the lasers are accurately aligned with the hemispherical bump on the receivers is there anything else I should look at. I've double checked that the receiver for laser 1, on the right hand side looking towards the receivers, is connected to D2 and that for laser 2 to D3.

Flighter · Mar 27, 2023

Further thoughts, would room light (it was a dull day outside) affect the receivers?

Niglyn · Mar 27, 2023

ic-racer said:
Seems the manufacturer updated the sensor parts from SIC553-04 to PIC0103SL and PIC0903SL

This is what the great interweb says. However, I cannot find a retail outlet to purchase them. I can get normal photo-transistors & photo-diodes, but would then have to add the trickery that is already included in these little wonders.

ic-racer · Mar 27, 2023

After fiddling with the virtual model, I believe the results Flighter are seeing in the travel time are related to the sensors being reversed #1 for #2.

This could be due to how Flighter has the camera oriented in the device. Try flipping the camera around.

I was able to duplicate Flighter's display by reversing them.
So this is what I get when pin 3 is triggered first and pin 2 second. See below:

ic-racer · Mar 27, 2023

Niglyn said:
This is what the great interweb says. However, I cannot find a retail outlet to purchase them. I can get normal photo-transistors & photo-diodes, but would then have to add the trickery that is already included in these little wonders.

My impression is either will work fine as long as the HIGH/LOW state of each device is respected. I'm pretty sure Wokwi model simulates the old version as LIGHT = LOW state, and your software works correct with the new commonly available devices which I believe is LIGHT = HIGH state.

Xylo · Mar 27, 2023

Flighter said:
Further thoughts, would room light (it was a dull day outside) affect the receivers?

It depends on the receivers themselves and which wavelengths they are sensitive to.
You could wrap the sides with a bit of electrical tape to make a tube to see if it improves any.

snusmumriken · Mar 27, 2023

Flighter said:
I don't think so, I've been getting results that I don't really understand but haven't had time to investigate, camera was an OM1 set at 1/500 second.

The following screenshot was taken of the serial monitor window in the Arduino IDE [Tools > Serial Monitor].
View attachment 333839

.

I haven’t had time to study the code in detail yet, but given that kind of output I’m wondering if there is a timer overflow issue? I’ll dig into it tomorrow if no-one else gets there first.

Build a shutter tester for Focal Plane shutters - Cheap, Easy & it Works

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