Vision System Enclosure

[ABNewbie]

I'm constructing a vision system using a 1722 camera and I'm trying to figure out what would be a good material to use for the enclosure side panels. The enclosure is going to be a 14"X14"X14" cube that's going to sit over a conveyor belt. There's going to be two 12" fluorescent light bulbs inside the enclosure with the camera mounted from the top of the enclosure looking down at the conveyor.

I'd like to use a white bright material (cardboard or plastic) for the enclosure sides so the light from the fluorescent lights can deflect off the top side and down onto the parts on the conveyor. Anybody can suggest a good material to use? White ABS plastic?

TIA

Dave

[ADL]

Dave, 

I'm assuming this is your first machine vision system.

I would warn you that lighting is always the problem for machine vision systems, and you should probably do some trial and error work with the lights and the materials before you start.

I would also say that using "home depot" type flourescent type lights will sometimes become a problem later when you replace the bulb.

If you are going to use home depot type lights get a number of bulbs, and use them, and make sure your system is still stable.

Onto the material, its not as big an issue as the lights, delrin is very easy to use, and machine. 

Good Luck 

Andy 

[ABNewbie]

Thanks for the info ADL.  My plan for the lights was to use vision lighting by Banner engineering.  They make high frequency fluorescent lights.  They are expensive ~$350/light so I'm assuming that there are no issues wiht them as you describe below.  But if there is, the home depot style lights might be a much cheaper option. 

Thanks for the info on Delrin, I'll have a look.   I just want to make sure the sides are bright white so all the light can reflect down onto the conveyor.  I was also looking at white ABS, but one of the sides is not smooth.

[pallen]

Hi Dave,

Just thought I'd chime in quickly about lighting. 

The biggest problem with "Home Depot" style florescent lighting is that the old style ballasts are not high frequency, and you very likely will see fluctuations in your captured images.  

Most electronic ballasts though are now high frequency.  I've used standard T-8 bulbs and fixtures in the past for vision systems and as long as the diffusing was good, they worked very well.  Plus, they were much cheaper than any specialized lighting.   

In the past I have also used Sintra as semi-reflective material.   http://www.solarbotics.net/starting/200207_sintra/200207_sintra.html

Message Edited by pallen on 04-19-2010 01:20 PM

[ABNewbie]

I have also thought of Sintra, but I shy away from it because it's very soft, so I don't think it would be very durable and it's more of a matte finish, so I'm not sure if it would deflect the light, but I could be wrong.

[pallen]

I actually found the matte finish to be of help.  One that is highly reflective can actually be more of a problem unless your light source is already heavily diffused.

[muks]

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pallen wrote:
I actually found the matte finish to be of help.  One that is highly reflective can actually be more of a problem unless your light source is already heavily diffused.

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I agree and it is better to avoid un even lighting and better to go with matte finish.