Open source generic component feeder

[Nails]

How do you plan on making the sprocket wheel cheaply? Is there a source for them where you can just buy it?

[stewi]

The only source I know is LaVezzi SK-Precision Sprockets & Rollers
They are definitely not cheap.
The sprocket wheel is a flat, 0.7 mm thick part with square teeth. Initially, I plan to have it laser cut and will have a stamping tool made, if I can make any money out of this project.

[jwolin]

Stewi, thanks so much for sharing this idea. I love open source thinking! If you get anywhere with this concept you might consider publishing your design at cncmentor.com (shameless plug). I don't have much personal experience with this, although I did tear apart a pick and place machine once that I picked up at auction and had quite a bit of fun trying to figure out how it worked.

[stewi]

How do you plan on making the sprocket wheel cheaply? Is there a source for them where you can just buy it?

I propose a wheel with 40 sprockets and 80 grooves in order to read 2 mm pitch.
Anybody here in this forum, who can build this to a decent price?
Wheel diameter is 50.93 mm, material 0.7 mm thick.

[jcdillin]

I'm in the process of getting my laser cutter set up in the next day or so, I can cut some out for you.

I would love to get set up with some feeders like this, i'm currently trying to implement drag feeders.

[stewi]

That would be great!
I'll make modifications to my hobby CNC and should be able to mill some of the other parts as well.
Last change to the sprocket wheel: I made the inner hole larger.
DXF added

[jcdillin]

So is the .7 mm thickness critical? I'm not finding that size easy to get, I can get .635 mm or .762 mm

[stewi]

I should finally convert to imperial!
I'll anticipate .635 and change the drawing.

I also found the pinion (pinch wheel) out of stock and will likely change to inch size as well https://sdp-si.com/eStore/PartDetail...51&GroupID=439

[daedalus]

Stewi: Have you considered having these made with rapid prototyping? Places like shapeways.com are really pretty cheap now, and it would allow people without machine shops to order one-offs. It would definitely make the sprocket wheel production easy, and I'm guessing could be used for the whole lot with a bit of thought. It also has the advantage that you can integrate features like the spring holding the incoming tape, and the motor mounts, reducing your part count.

[stewi]

Thank you for the input.
The last time I checked on rapid prototype (quickparts.com), it wasn't that inexpensive.
For a small production I would consider making a silicone mold and use aluminum epoxy cast.
I'm currently building another CNC machine, this time with the capability of tilting the router head. Together with the 4th axis, I'll set up a rotary chuck and can hopefully mill a stack of discs and do the sprocket wheels as well.
Else, I would also attempt to cast these wheels in a silicone mold, once I have one golden part.

I'll certainly continue building a few feeders to proof the concept, but I didn't mean to start a production of component feeders to diminishing potential customers in US.
I was hoping somebody would pick up from here, build a few parts and share these parts within the home built P&P community.

[daedalus]

shapeways is about 1.35$/cubic cm of material in part for their economy plastic (SLA process). That means that the wheel you are building would be a couple of dollars, and the surface finish is pretty good. It also means you can do the whole wheel (spokes + hub) as one piece. Their minimum order is a few dollars, so its hard to go wrong.

The reason I suggested doing as much as possible this way is that shapeways have a store feature where you can put your design on their site, then people can just order the whole set made for a fixed fee. Effectively its a kitting service less motors, shafts, and bearing bits.

I have done a fair bit of epoxy casting at work over the years, and these days I use shapeways to make my moulds in RP plastic, then just cast into them under vacuum, the part quality is pretty good that way, and no more waiting around for rubber molds to vulcanise.

[stewi]

Thanks again. I'll send some drawings for a quote.
In order to incorporate the motor/gear mount into the base, I'll remove the material in the rear and have just the 4 fins sticking out. See attached drawing
Making the coil spring out of plastic as well, which supposed to take the shock load from the tape reel, looks like quite fragile to me, although I like the idea of reducing the number of parts.
After all, I like the idea of bringing a third party vendor in and folks order directly there. I think this is the true spirit of open source.