Printing of a Tiny Pulley Question

[hdtvjeff]

Hello again,

Attached you will see a half inch pulley from a Panasonic Cassette deck,

I need a copy of this pulley but with a slightly larger diameter with the other measurements staying the same.

Is that possible with a 3d printer?

Also, with a 3d printed pulley will it be smooth enough for transport with a rubber belt?

Thank you so much

[fred_dot_u]

For a one-off item such as you've described, you might want to use an online service such as shapeways and have the part printed with an SLA printer. The results will be microscopically smooth and reasonably strong for your application. If you can create the STL file (or other accepted format) the service can provide a quote. These services can 3D print in multiple types of material. If you required it, even stainless steel is a possibility.

[hdtvjeff]

Thank you Fred,

I was curious too, with a good 3d printer at home could it be done at home with the right filament and knowledge or are finely detailed prints best left to outside sources ?

[fred_dot_u]

It's not impossible to make such a pulley on a home machine, but the thin parts are at a higher risk of failure. High strength nylon may be a good choice, even perhaps a quality PETG filament would hold up, considering the low forces involved in the use of the pulley. I'd probably try PETG first at 0.100 (100 micron) layer height. Perhaps use PLA at 200 micron layers for initial construction to confirm correct sizing, then switch to PETG for the final print.

[airscapes]

You would design it differently if possible, is there really a need for the indentation between the hub and the pulley surface? I would not hesitate to print this with Alloy 910 and a .25mm nozzle on my Makergear m2. 1/2 in diameter is not that small.
Would I say for you to go buy a printer and be able to print this without spending several months learning, No. Would it be cost effective, absolutely not. Can it be done, absolutely.

[hdtvjeff]

The pulley in question needs the edges on both sides to keep the belt in place; guess it was the way Panasonic engineers designed it.

[airscapes]

No I was referring to the area between the hub and the outside.. If you are going to create a 3d model to print and it could be solid in that area it is easier to print.

[hdtvjeff]

The underside of that pulley is solid; so I gather the side you are seeing can be solid too!

[airscapes]

Would need to determine if it slides over a boss containing the shaft which would require that concave area.

[curious aardvark]

That's not small - THIS is small:

allpartsondime_622x600.jpg

gears.jpg

Also mass produced:

massproduction_800x276.jpg

The blue gears were made with colorfabbs xt (a polyester) and while only 1mm thick, impossible to bend between 2 fingers. The black rubber tyres were made with a rubber type tpu that i use for items that woud have been made from conventional black rubber. Part of my mate's house guttering is held together with parts I made from it :-)


basically - yes your pilley will be easy to design and easy to print. pla would be absolutely fine, as would pet-g and even a stiff flexible pla.
If you want to try yourself, have a look at these two printers.

https://www.amazon.com/s?k=monoprice...b_sb_ss_i_3_15

and probably the cheapest ready built half decent machine around: https://www.amazon.com/Monoprice-Cal...r=8-6-fkmrnull

For that kind of item openscad is definitely the design program of choice: http://www.openscad.org/

Easier to use than it looks and once you've written a parametric script you can make different sized pulleys inside a few seconds just by changing a couple numbers.

And as the lads say, either go for a an online print agency - or, like a mate of mine just did on my bbq forum - find alocal library with a 3d printer. I made some little adaptors so you can use cheap diamond plates with a knife sharpening system - I sent him the stl and he got them printed at a local library for 40 cents an item - much much much cheaper than any online agency

What you're looking at is probably no more than a few lines in openscad, someone will no doubt run a script off for you.
We're like that round here :-)