[keebler303]

Here is how I did it:

1) I downloaded the solid model from www.sdp-si.com for the gear I wanted. Then generated the code for the teeth. A 1/8" end mill was just a tad too big so I told artcam it was a .120 tool and used a 1/8" anyway, close enough for me.

2) I used a 1/2" thick piece of solid surface (countertop) for the pullies.

3) Threw the solid surface on my bridgeport and went to town. I used 3000 RPM , 10 ipm and .1" stepdown.

Results:

Worked really well. The belt fits like a glove and the teeth are really clean and smooth. May not be great for a long term deal but its pretty good. I am using them for a short time to determine if I have the ratio I want before spending money on the real ones.

Sorry for the poor quality pics, old digital camera.
Maybe this will be of use to someone.

Matt

[gmfoster]

Matt

Looking good...

Garry

[Zumba]

Cheap prototyping... I like it.

Good work.

[bcromwell]

Never thought to use SS counter top, Good Idea!

B

[Ken_Shea]

Matt,
Good thinkling on the part and it looks great.

What model belt is that ?

Ken

[keebler303]

Ken

its an HTD 5mm pitch

Those were both 62 teeth straight from the solid model.
Today I made a 100 tooth from scratch using the same tooth profile and it worked great as well.

The scrap I am using is just a sink cutout from a countertop. It can probably be found for free at countertop places and it cuts really clean.

Matt

[sdopp]

Great job, looks good
that counter top material is fun to work with

Skip

[digits]

Lovely! I need to make some timing pulleys myself - I can't decide whether to make them like yours and then add some flanges, or just to try cutting them 'side-on' on my rotary table. Either way, having accurate CAD data for pulleys that will fit my belts is very,very handy - thanks for the link

[keebler303]

You have to be careful which type of belt you use. Most are not friendly to cutting this way. The HTD happens to be basically round. The trapezoid shaped profiles would require a form cutter and would be hard to get square corners where your flanges were.

If you are planning on HTD then you should be good. With a ball end mill that would work rather well. I am probably going to epoxy on some formica rings for the flanges. I haven't gotten that far yet.

Good luck and post up the results
Matt

[Karl_T]

FWIW, I used another approach.

I drew the pulley cross section up in AutoCad using Machine Handbook data. (Your web site link would have saved time here) Then printed out one tooth at 50 X magnification.

I put a cutout of the tooth on the optical projector and then made a fly cutter exactly the same by checking on the projector and then grinding to fit outline.

After this its a piece of cake to put a shaft in a dividing head, cut one tooth, index, cut another tooth.

Karl


Karl

[keebler303]

Karl

you are right, this is the form cutter method I mentioned above. The beauty of this method is it uses a stardard cutter and could be done on as little as a 2 axis cnc machine.

Matt

[ajmoir]

I'm building my first cnc machine, currently looking at pulleys and belts from SDP/SI and you come along and show me how to make my own pulleys with a cnc machine.

Chicken/ egg catch 22, arghhh

There has been so many times in my build that if I already had the machine I could have whipped up the parts in no time or tested three different options. Instead I have to send out for stuff.

[keebler303]

thats why the second machine is so much easier than the first.

Honestly, it would probably be possible to make some decent pullies by hand. I would print out the drawing of the pulley. centerpunch and drill each notch first. Then cut out the diameter with a jigsaw or similar and clean everything up with a file and sand paper. If you got those made, you could use them on your cnc machine to make some better ones.

Matt