Author Topic: Wheels!  (Read 1020 times)

Lob0426

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Re: Wheels!
« Reply #15 on: December 03, 2016, 11:17:36 AM »
Some plastics are a pain to mill. You have to have enough RPM to cut cleanly but not melt. Those eccentrics might do well from a 3D printer.

Getting returns from these companies is a pain. When my 500mw laser module died I did not bother, I upgraded it with a 2W diode and new driver. I have 4 Laser modules now. 1 stock 2500mw, 1 stock upgraded to 2W, two built from parts, 1 2W and a 3W TTL. When my MOSFET went out on a L7 I bought a replacement and then repaired the first one. I have lost several stepper drivers but had extras. With two machines I have lost twice the parts! LOL
Richard
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Agastar

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Re: Wheels!
« Reply #16 on: December 07, 2016, 10:16:17 AM »
Delrin seems to do alright on a lathe. I wonder how well that would work for some wheels.

beikeland

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Re: Wheels!
« Reply #17 on: December 07, 2016, 10:29:31 AM »
Those black wheels I got are supposedly made from POM, and I'm inclined to believe its true.

POM is more or less the same as Delrin(R) afaik? And POM is easy to both mill and turn, but I have limited POM stock so I tend to save it and opt for the much cheaper and readily available HDPE chopping boards.

Agastar

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Re: Wheels!
« Reply #18 on: December 07, 2016, 10:45:47 AM »
Oh yeah, cutting boards, now that is a really great inexpensive source for some plastic :)

beikeland

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Re: Wheels!
« Reply #19 on: December 07, 2016, 11:10:39 AM »
Hehe, IKEA is my #1 supplier for stock to use on the CNC.

They also have a 2-pack of red and green LDPE cutting boards that make pretty decent machining wax when melted down together with their candles. Tend to make two different hardnesses with the two colours, but its so much cheaper than buying machining wax!


Agastar

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Re: Wheels!
« Reply #20 on: December 07, 2016, 11:25:58 AM »
Ooooh! We have an ikea around us :D Time to go online and see what they have :)

Lob0426

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Re: Wheels!
« Reply #21 on: December 07, 2016, 04:30:36 PM »
POM and Delrin are the same material. Making your own wheels means you have control of the final product. The Chinese wheels are mass produced and not that consistent. That makes it real hard to get them adjusted right.

Delrin is almost the same settings as machining Aluminum. Just make sure your tool is sharp.

Never thought of using cutting boards as stock, I will have to try.
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw

Experimenting with Mega2560 board upgrade

beikeland

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Re: Wheels!
« Reply #22 on: December 07, 2016, 09:03:28 PM »
True that its a good idea to be sceptical about anything made from Chinesium - but the wheels I got were actually pretty well made, don't remember the runout  I measured but I was thinking to myself "thats quite alright"; and evidently far superior to the original wheels as my machine now draw near square squares..

Lob0426

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Re: Wheels!
« Reply #23 on: December 07, 2016, 09:22:33 PM »
I have not figured it out, but a mega2560 board will draw a better circle than a Nano!
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw

Experimenting with Mega2560 board upgrade

beikeland

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Re: Wheels!
« Reply #24 on: December 07, 2016, 09:24:26 PM »
My money would be on a different cpu_map.h file and a higer TTL frequency resulting in a better mm/Hz ratio ;)

Lob0426

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Re: Wheels!
« Reply #25 on: December 08, 2016, 09:28:20 AM »
There are many things it could be. You increase the RX/TX buffers. You increase the block and segment buffers. There is a whole bunch more working memory. There are extra clocks so less of the pons used are shared.

The pwm rate for TTL would have no effect on movement. It is on a separate pin unlike on the Nano. 
Richard
A5 2.5W w/homing switches on L7
A5 2W diode self upgraded from stock 500mw

Experimenting with Mega2560 board upgrade

beikeland

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Re: Wheels!
« Reply #26 on: January 07, 2017, 04:17:13 AM »
Just saw an alternative to the somewhat pricey 6x1 precision shims. Regular M5 split washers are roughly 6mm OD and 1mm in height, so they only contact the inner race of the bearing. And become flat when tightened and provide a little extra pre/loading as well.

My 3d printer kit came with these, and it works well.

ROSS

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Re: Wheels!
« Reply #27 on: January 07, 2017, 05:10:40 AM »
Just saw an alternative to the somewhat pricey 6x1 precision shims.

Where?  EBay??
.
Lasers are wonderful machines..not ONLY  can they cut a finger off BUT  they can also cauterise it at the same time.....

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beikeland

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Re: Wheels!
« Reply #28 on: January 07, 2017, 06:18:25 AM »
I've stopped checking eBay, but I'm sure you'll find them there as well, just search for m5 split washer.


100 pcs should set you back $2-3