Source for white plastic 8.5"x11" printer sheets?

RobotWorkshop

I've seen several places carry plastic transparency film for laser and inkjet printers that can work well for printing circuit board traces and optical encoders. Does anyone happen to know of a source for similar sheets but in a white plastic that would be opaque? I would like to get some for printing reflective encoder wheels with a laser printer that will be durable. I've seen smaller plastic sheets for making labels and ID cards but haven't found full 8.5" x 11" sheets like the transparency film.

Another option would be the higher end water/smuge proof papers for Laser printers. I just want to use something that will last.

If you have any suggestions or sources please let me know.

Robert

Tracy Allen

I like Ilford "Smooth High Gloss Media". link
It is a polyester plastic film that is textured for inkjet on one side, and it holds brilliant sharp colors. After printing I laminate the inked side under a clear, thin, pressure laminating film, and that makes it quite water-wickproof. I use it for labeling breakout terminals and such things. It is meant for inkjet or dye printers, but I have found it also works fine in a color laser printer.

Phil Pilgrim (PhiPi)

For laser printers, both of these should perform well:

Teslin, a synthetic laserable paper.
Rite in the Rain, a waterproofed paper product.

-Phil

RobotWorkshop

Thanks for the suggestion! I will see if I can get some of those sheets and can try them in the Laser Printer. That should work out well for making a custom reflective encoder.

Robert

Tubular

Also, http://www.graytex.com

Some of their paper is fully synthetic (good for what you want), and some is kind of plastic in the middle with paper on the outside

RobotWorkshop

I appreciate all the suggestions and have ordered a pack of the waterproof printer sheets to try. I'm sure at least one of those will work out. If they arrive in time I may be able to get them done this weekend. I'll let everyone know how they work out.

Thank You!

Robert

RobotWorkshop

This worked out great!! I was able to get some # 6511 DuraCopy Paper from Rite in the Rain and it is pretty amazing stuff. The encoder wheels came out sharp and clear and the toner seems to adhere to the sheets very well. After coming off the printer there was a slight curl to it. I ended up taking them over to a local Kinko's copy center and then had the sheet laminated. They are perfectly flat now and very sturdy. It will also protect the image of the encoder. I'm really happy with the results.

So far the testing is working out well and I think I'll be using this for other encoders as well.

Robert

RS_Jim

I am curious as to the resolution of your encoder?
Jim

RobotWorkshop

RS_Jim wrote: »

I am curious as to the resolution of your encoder?

Hello Jim,

For the particular robot these are going on the resolution isn't that high. They are being mounted directly to the wheel. It will help keep track of how far it has gone and what direction. I will be doing some higher resolution ones as well but may need to use different IR sensors. An example of the encoders is attached here:

encoderwheel_quadrature.pdf

Robert

Phil Pilgrim (PhiPi)

Robert,

Just an FYI: You don't need two separate tracks to make a quadrature encoder. Just position both sensors over one track, such that their positional relationship varies by n + 1/4 full cycles of the bar pattern.

-Phil

RobotWorkshop

Phil Pilgrim (PhiPi) wrote: »

Just an FYI: You don't need two separate tracks to make a quadrature encoder. Just position both sensors over one track, such that their positional relationship varies by n + 1/4 full cycles of the bar pattern.

Hello Phil,

I was originally going to use a single track. The main issue is the positioning of the sensors. When using a single track you have to adjust the position of each sensor and it is then fixed to that particular encoder. Since I mount the sensors on a protoboard I am usually limited by the .100" spacing. With that I need to get the sensors close and then make the mounting adjustable to slide in and out from the center of the encoder to get the spacing right. Frankly it can be a PITA. Having two tracks does seem to have a big advantage as long as there is room for both tracks. With two tracks I just position each sensor inline. The only spacing is to make sure each one is centered over each track. It eliminates the need for any further adjustment. With this I can easily change the resolution of the encoder by just printing a new one and no longer need to adjust the sensors! One less thing to mess with.

Now if I need to use the optical encoder sensors that already have both sensors in one then I would just print a single track with a resolution to match. I'll use whatever method works best for the task at hand.

Robert

Phil Pilgrim (PhiPi)

I see your point: changing resolutions also changes the sensors' relative mounting positions. This brings up an interesting math problem (well, interesting to me anyway): what relative positioning around the disc will accommodate the most different resolutions? IOW, given a circumference C and a distance D between the sensors, the width of one full cycle will be C/n, where n is the resolution in cycles per revolution. So the spacing has to be D = (k + 1/4) * C/n, where k is some integer. The idea is to pick k such that:

(k+ 1/4) * C/n = (j + 1/4) * C/m

for as many different useful values of m as possible, where j is also an integer.

-Phil

RobotWorkshop

Here is a picture of one motor/wheel assembly with the custom encoder and wheel. With the sensors inline I can swap the encoder wheel to change the resolution.