Freescanning Rig

[onkino93]

Hi Magweb,
Thanks for you indepth reply,
You can indeed get that Gear you mentioned on the Connrad UK website for around 20euros. Just type the code in the search and it comes up pretty easy for people who want to know.

Right now i am purchasing-

Arudino D and the Motor shield kit
Camera tripod
Green laser with Adjustable focus

Conrad DC motor
Stepper from printer(still looking)

I already have-

Trust 5400 (but am will to upgrade)
Nice TV lens.

David free version.

[MagWeb]

Hi,

@ Greg:
I´m fighting against filesizes fusing the meshes( this planeless scanning rises the size of the partial meshes) and my memory has to be expanded. Nice colored pictures for people loving this instead of maths are comming soon

@ Joe:
I added my code as it is now. It´s quite basic and has to be expanded.
Message settings:

Code: Select all

      <Messages>
        <AnalyzeImage value="M" defaultvalue="" description="Is sent when DAVID starts to analyze an image" is_editable="True" type="String" />
        <Close value="C" defaultvalue="C" description="Is sent when DAVID is closed" is_editable="True" type="String" />
        <EraseScan value="E" defaultvalue="E" description="Is sent when the scan is erased." is_editable="True" type="String" />
        <EraseTexture value="" defaultvalue="" description="Is sent when the texture is erased." is_editable="True" type="String" />
        <GrabImage value="" defaultvalue="" description="Is sent before DAVID grabs an image" is_editable="True" type="String" />
        <GrabTexture value="G" defaultvalue="G" description="Is sent when a texture has been grabbed" is_editable="True" type="String" />
        <ModeCalib value="1" defaultvalue="1" description="Is sent when DAVID prepares for calibration" is_editable="True" type="String" />
        <ModeScan value="2" defaultvalue="2" description="Is sent when DAVID prepares for scanning" is_editable="True" type="String" />
        <ModeTexture value="3" defaultvalue="3" description="Is sent when DAVID prepares for texture grabbing" is_editable="True" type="String" />
        <Open value="O" defaultvalue="O" description="Is sent when DAVID has been started" is_editable="True" type="String" />
        <SetupCamCalib value="" defaultvalue="" description="Is sent when user starts to adjust camera settings for calibration." is_editable="True" type="String" />
        <SetupCamScanning value="U" defaultvalue="" description="Is sent when user starts to adjust camera settings for scanning." is_editable="True" type="String" />
        <SetupCamTexture value="" defaultvalue="" description="Is sent when user starts to adjust camera settings for texture grabbing." is_editable="True" type="String" />
        <StartScanning value="S" defaultvalue="S" description="Is sent when Start is clicked (usual scan with background or Reference Scan)" is_editable="True" type="String" />
        <StartScanningRepetition value="S" defaultvalue="S" description="Is sent when Start is clicked (Repetition Scan of scanning without background)" is_editable="True" type="String" />
        <StopScanning value="T" defaultvalue="T" description="Is sent when Stop is clicked" is_editable="True" type="String" />
        <ScanSaved value="Z" defaultvalue="Z" description="Is sent when a scan has been saved or forwarded" is_editable="True" type="String" />
      </Messages>

Do not forget the voltage reduction, when you plug in your laser!

Gunter

[Simon Spooner]

If anybody finds a readymade gear fitting to small steppers please post!

Is this what you are looking for?
http://cgi.ebay.co.uk/Romford-Gear-and- ... 7C294%3A50

[joecnc2006]

If anybody finds a readymade gear fitting to small steppers please post!

Is this what you are looking for?
http://cgi.ebay.co.uk/Romford-Gear-and- ... 7C294%3A50

That worm gear is 0.094" I believe the motor shaft is 0.196" of the motor MagWeb posted, this may be a standard for a nema 17 motor? I will check also what mine is also, and maybe we can find a good supplier, or someone here can manufacture some 1:100 reduction gear and worm gear for others.

[Simon Spooner]

That worm gear is 0.094" I believe the motor shaft is 0.196" of the motor MagWeb posted, this may be a standard for a nema 17 motor? I will check also what mine is also, and maybe we can find a good supplier, or someone here can manufacture some 1:100 reduction gear and worm gear for others.

Sorry, my mistake. Wouldn't it be easier to manufacture a reduction "coupling sleeve" to fit over the motor shaft and give a reduced diameter and then use off the shelf gears like the ones I linked to, rather than trying to manufacture the gears themselves?

[joecnc2006]

That worm gear is 0.094" I believe the motor shaft is 0.196" of the motor MagWeb posted, this may be a standard for a nema 17 motor? I will check also what mine is also, and maybe we can find a good supplier, or someone here can manufacture some 1:100 reduction gear and worm gear for others.

Sorry, my mistake. Wouldn't it be easier to manufacture a reduction "coupling sleeve" to fit over the motor shaft and give a reduced diameter and then use off the shelf gears like the ones I linked to, rather than trying to manufacture the gears themselves?

I was just thinking about a coupler this morning.

[MagWeb]

Hi,

Simon and Joe, thanks for your suggestions. I thought of something similar to http://de.nanotec.com/stirnradgetriebe.html, but less expensive and a bigger reduction. Think, such a gear/motor combo would be a nice thing for the DAVID shop.

Here is a first picture of a scanresult using that rig:
A floor mosaic I did 13 years ago. Ok - thats not an ideal object - but it`s raining and raining outside. The floor tiles around are 110mm X 110mm. So the scanned area is about 1m x 1m.The groove between is less than 1mm in depth and in the marble mosaic less than 0,5mm to zero. Done in 9 partial scans to see whether the scans will be precise enough to be flat. The biggest problem was aligning the scans. Topology was too similar to give a unique result.

Gunter

[frankiben123]

wow nice post.............
sales tracking software

[Simon Spooner]

it performs nice motion with only a little backslash, that can be easily avoided with some rubber band.

Gunter

Gunter, can you please explain the use of rubber band to reduce backlash? What is the band attached to and from?

Thanks,
Simon

[MagWeb]

Hi Simon,

Now (a little modification to the posted images) I use the rubber band around the aluminum bar to the laser. A little force is enough to keep the pinions always in contact to the same flanks...

Gunter

[jantje]

Magweb
Great work. Good thinking. I'm planning to copy your work but I haven't fully understood all of it.
My first question is in regards to the cathode lamp. I like the idea of the cathode lamp being added. It makes the setup a nice all in one solution. However because the quality of the work you deliver I can't make out how the lamp fits into the frame. Did you make a hole in the aluminum bar and glued the lamp and used aluminium paper?

My second question is in regards to the connection to the tripod. I ask myself is why you have used a "holder" for the connection to the tripod and not for a simple wired hole. I could understand this option if there is a need for moving the position of the connection. However on all the pictures you provided the "holder" is located at more or less the same location. Moreover this location is in front of the lamp . Can you share you thoughts/reasons on this subject?

My third question is on behalf of how the laser is attached to the gear. Is this directly on the axis? I assume you made the laser holder and gear connector yourselves.

My last question is on behalf of the operation of the setup. For the repeatability scan the laser needs to restart from the same position. How do you put the same startup position? I see no positioning equipment.

Again you have done a great job. I'm looking forward to your help
Jan

[MagWeb]

Hi Jantje,

sorry if the images are not detailed enough, but I wanted to show the concept and was sure that there will be questions
So:
1.
You'r right the cold cathode is glued inside the rectangled tube and shines through a hole I routed into the tube. But you could also use a U-profile. The idea is that one can move the laser/stepper/controller combo over the lamp to decrease the cam/laser distance for smaller scanning purposes. Yes the slide hides a part of the lamp - but smaler setups need less light. ( @ cold cathode lamps: attention 600V so make sure that there´s a good insulation).
2.
I made a connection that make it possible to keep the bar in a balance. A second advantage (oriented vertically) is that you can adjust it higher.
3.
Yes, the laser's fitting is right on the gear's output shaft and is homemade as well as the connection to the gear, and all the black plastics. I did it in 15mm plastics on my CNC. If you want the 2D drawings to mill them, I could post them - but I think different materials and tools may need different solutions - Should I do some more pics?
4.
A fixed endswitch doesn´t make much sense for scanning on different distances (besides the risk of colliding with the bar) . Your starting point Zero has to be set by hand, for the first detectable laserplane will always be somewhere else (or use the brandnew NoLine message in the beta Sven posted today - let´s see). The controller counts the steps the stepper performs from that point on. So the stepper finds point zero again simply by doing the same number of step backwards as it did forward before.

Gunter

[marting]

Hi,

@ Greg:
I´m fighting against filesizes fusing the meshes( this planeless scanning rises the size of the partial meshes) and my memory has to be expanded. Nice colored pictures for people loving this instead of maths are comming soon

@ Joe:
I added my code as it is now. It´s quite basic and has to be expanded.
Message settings:

Code: Select all

      <Messages>
        <AnalyzeImage value="M" defaultvalue="" description="Is sent when DAVID starts to analyze an image" is_editable="True" type="String" />
        <Close value="C" defaultvalue="C" description="Is sent when DAVID is closed" is_editable="True" type="String" />
        <EraseScan value="E" defaultvalue="E" description="Is sent when the scan is erased." is_editable="True" type="String" />
        <EraseTexture value="" defaultvalue="" description="Is sent when the texture is erased." is_editable="True" type="String" />
        <GrabImage value="" defaultvalue="" description="Is sent before DAVID grabs an image" is_editable="True" type="String" />
        <GrabTexture value="G" defaultvalue="G" description="Is sent when a texture has been grabbed" is_editable="True" type="String" />
        <ModeCalib value="1" defaultvalue="1" description="Is sent when DAVID prepares for calibration" is_editable="True" type="String" />
        <ModeScan value="2" defaultvalue="2" description="Is sent when DAVID prepares for scanning" is_editable="True" type="String" />
        <ModeTexture value="3" defaultvalue="3" description="Is sent when DAVID prepares for texture grabbing" is_editable="True" type="String" />
        <Open value="O" defaultvalue="O" description="Is sent when DAVID has been started" is_editable="True" type="String" />
        <SetupCamCalib value="" defaultvalue="" description="Is sent when user starts to adjust camera settings for calibration." is_editable="True" type="String" />
        <SetupCamScanning value="U" defaultvalue="" description="Is sent when user starts to adjust camera settings for scanning." is_editable="True" type="String" />
        <SetupCamTexture value="" defaultvalue="" description="Is sent when user starts to adjust camera settings for texture grabbing." is_editable="True" type="String" />
        <StartScanning value="S" defaultvalue="S" description="Is sent when Start is clicked (usual scan with background or Reference Scan)" is_editable="True" type="String" />
        <StartScanningRepetition value="S" defaultvalue="S" description="Is sent when Start is clicked (Repetition Scan of scanning without background)" is_editable="True" type="String" />
        <StopScanning value="T" defaultvalue="T" description="Is sent when Stop is clicked" is_editable="True" type="String" />
        <ScanSaved value="Z" defaultvalue="Z" description="Is sent when a scan has been saved or forwarded" is_editable="True" type="String" />
      </Messages>

Do not forget the voltage reduction, when you plug in your laser!

Gunter

Hi Magweb,
Is the above your programming for operating arduino + motor sheild? I've just purchassed a set and so am an absolute beginner in this arduino setup so I thought maybe looking at others programming will help me getting mine up and running in a shorter time. What I have in mind is to slowly rotate the laser while scanning, after having doing so return it to its start position at a faster speed and at the same time rotate a turn table on which the item to be scanned will be placed. In other words I will be using 2 small stepper motors. Any suggestions to start off with ( asi I am suspecting that would need an elaborate writeup)? I've also been looking at the manual but have not been making so much sense......maybe I need to read with a slower pace untill it sinks in!
Thanks
Marting

[MagWeb]

Hi,

no, this are the parameters you've to set in the advanced settings to communicate with the code I posted as an attachment in the same post.
"StepDAV22_06.pde.zip" - download and unpack.

Open the code with the Arduino software. Load it to your Arduino clicking the upload button (ok you´ve to plugin your board via USB and power the shield to execute the code with motors )
Now your plugged on shield should work when you use the same outputs on the shield as I did. Please wait connecting the laser I'll post the layout of the voltage reduction on monday.
BTW.: I would use a stepper to move the laser and a hobby servo to rotate the object (I didn´t try that combination until now). So you´ve free outputs for switching laser and light...

Gunter

[marting]

Hi Magweb,
Thanks for the support. At the moment I'm trying a different setup with arduino, however am a bit slow due to time availability. On the other hand considering that I'm new with arduino, I have to iron out programming wrinkles as everyone does. I'll be posting as soon as I have done some proper work with the setup.
Marting