need help to make pulley reduction

Hi All,

does anyone have any one has any idea where to find gt2 pulley reduction gears, i am new here . Or any stl file to print them.
I was thinking of making a pcb router and need to find ways to get the 2 micron step size for high density chips.

Any thoughts?? will try to use laser diode for the engravings.

Timi,

I think 50 micron is about the best that low end printers / routers can do.

The GT2 pulley has little to do with it.
There must be some pulley diameter for minimum teeth engagement

Stepper motor rotation per step is poistioning
Standard Stepper motor 1.8 deg per step
They can be controlled at full step, 1/2, 1/4, 1/8, 1/16, and 1/32 step
so perhaps .05 deg rotation minimum.

There are geared stepper motors but they would be very slow.

A pull-pull system using fishing line -- may be able to use pulley diameter
close to motor shaft diameter

A very fine leadscrew also could be used --- but then there is backlash to worry about

If you want 2 um step resolution, you are going to have to build the machine so that it doesn't flex by 2 um, even under the load of the cutter ripping into the copper and fiberglass of a circuit board. I don't know if you can find bearings and guide rails or even linear guides whose motion would permit such high resolution.

---

Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Hi all,

Thanks for the replies. I don't mean to use a cutter at those resolution but will go instead with the laser. Pulsing it out till it get the copper out. I need to put a camera and a few sensor to it to find if it has cleared all the Cooper out. But the first thing to worry is mechanical accuracy.

You guys are correct about the whole machine not flexing at 2um if it is going to have any decent speed, it has to be tough.

Thanks for the advices, I will need to make more calculation now.

Timi,

So I will need to start with a cast bed of some thickness to filter the vibration and put some mass on the linear bearing like 16mm rods. enlarge the machine envelope to take care of the linear bearing tolerances put longer rods and more distance between the linear bearings. It can be done for sure, but will need some casting .

I don't want too much speed, as I only want to make the interfaces to the high density chips then use a faster/lower resolution machine for the endpoint of the design.

Will need to buy some more precision tools always more tools .

Nice thing about having a 3d printer is you can always play with dimensions.

Timi,

What laser will you be using?

Laser Kerf (width of cutting beam)
range 80 - 450 micron

Seems like 2 micron in the unobtanium range?

No, I will go as cheap as possible. Will try to find some optics to combine 1 or 2 lasers. Then will use reflective hole to just let what I want through it so It will take care of the optics inaccuracies which are big. I think in the 100wat range as maximum. Will try to coat and make the geometry to sparse the light that gets reflected over a cooler. After all engineering is the science of % percentage of success not ultimate one. So if I can get the1/10 of 100wat and that from a 5~9 mm laser on a 1mm focus point of the lenses that pretty good for the layer of cooper I am trying to clean. It just will not be efficient but will do the job hopefully.

What do you thing of this setup???


Timi,

So how do you plan to cut this very small hole (< 2 micron)
in some type of reflective material.
and all this reflected energy is going where?
How will it be dissapated without melting optics or holder?

and

Do all this Cheap? Unless cheap to you is $100,000?

For me 2 - 5 watt blue (455nm) solid state laser for $200 -500 is cheap.

Why two lasers?

2 lasers --- phase adjustment?

Have you ever thought of steering laser beam with
2 axis mirror on voice coils?

Have you read
Making PCB's with a diode laser

[forums.reprap.org]

how-to-use-a-laser-to-etch-PCB

[makezine.com]

No I want 2um mechanical accuracy for the laser head movements. 15um is enough for the laser beam, at least for what I will try to use it for.. For the hole I will need to work with my brothers microscope to align plates to form the hole. No drill for it . 100wats is the max I think of what this setup can handle. Not that I will be buying it . There are Chinese 100wat co2 lasers or they claim to be I an not sure how they can claim it without calibration data though i haven't had one so cannot speak for those.. For power disipation the reflective Beam will be project as a mirrored beam and with a magnifying effect of the hole geometry to the opposite side so the area will be big enough to not damage it.. If I can disperse it to 6cm by 6 cm into cooling media it would be good. Black anodised aluminium. I just want to have with what I can get around. If you have any suggestion please let me know I am very interested. Been playing with optics and physics from childhood.


Timi,

and by the way, if i can get at 30-50 um it will be still usable. just will live with what i can archive .


Timi,