Search found 38 matches

by aam
Wed Aug 05, 2015 10:51 pm
Forum: Discussion
Topic: SO3 Z axis Upgrade discussion
Replies: 22
Views: 2511

Re: SO3 Z axis Upgrade discussion

A much longer spring would have the same advantage as a counterweight (nearly constant force over the entire range), but without the added mass. A helical spring would be impractically long, but a spiral (coiled) spring with a pulley might work. It could even be on the bottom belt pulley. Would the...
by aam
Mon Jul 27, 2015 8:36 pm
Forum: Member Projects
Topic: First project
Replies: 7
Views: 1487

Re: First project

And now it's upside down...
by aam
Fri Jul 10, 2015 9:02 pm
Forum: GRBL
Topic: Homing, only the Z axis
Replies: 6
Views: 1715

Re: Homing, only the Z axis

I'm not 100% sure,but what about G28 Z0?
If the Z axis is homed at the top of the Z travel, then G28 Z0 should make the Z axis go to the top.
Correct me if I'm wrong.

Edit:
Or was it G53?
by aam
Tue Jun 30, 2015 3:19 pm
Forum: Member Projects
Topic: PID Closed Loop Spindle Speed Control for Quiet Cut Spindle
Replies: 11
Views: 12532

Re: PID Closed Loop Spindle Speed Control for Quiet Cut Spin

Today I made a small PCB that holds the Arduino Nano I'm using as the PID controller. The milling was done on my machine (here you can see the steps of the process: http://www.instructables.com/id/PCB-designing-and-isolationmilling-only-using-free/ ). Came out nice and does its job! IMG_0748.jpg It ...
by aam
Fri Jun 19, 2015 11:30 am
Forum: Member Projects
Topic: PID Closed Loop Spindle Speed Control for Quiet Cut Spindle
Replies: 11
Views: 12532

Re: PID Closed Loop Spindle Speed Control for Quiet Cut Spin

Here's a simplified version of the code, I found that all the averaging and rounding isn't as necessary as I thought first. It works well! Just be sure to use shielded wires for the optical pickup and PWM connection, I used the cable of an old in-ear headset, made a huge difference in the stability ...
by aam
Sun Jun 14, 2015 1:56 pm
Forum: Member Projects
Topic: PID Closed Loop Spindle Speed Control for Quiet Cut Spindle
Replies: 11
Views: 12532

Re: PID Closed Loop Spindle Speed Control for Quiet Cut Spin

This looks great, I feel a really dirty hack coming on! I'm currently driving the Inventables Quiet Cut spindle using the spindle PWM output from grbl, so that I can set spindle rpm from g-code. So, if I can take that PWM output and feed it into your Arduino PID as the set point, I could have prope...
by aam
Sat Jun 13, 2015 9:57 am
Forum: Member Projects
Topic: PID Closed Loop Spindle Speed Control for Quiet Cut Spindle
Replies: 11
Views: 12532

Re: PID Closed Loop Spindle Speed Control for Quiet Cut Spin

I also found out that the PWM-RPM-ratio of my motor controller isn't linear. For example if you send a PWM value of 0 to the controller, the spindle has 0 rpm. If you send 255 PWM, the spindle has around 12000 rpm. But that doesn't mean that sending 127PWM will give you 6000rpm! I did some measuring...
by aam
Fri Jun 12, 2015 9:00 pm
Forum: Member Projects
Topic: PID Closed Loop Spindle Speed Control for Quiet Cut Spindle
Replies: 11
Views: 12532

Re: PID Closed Loop Spindle Speed Control for Quiet Cut Spin

I've made some progress, and it looks very promising! :D Now I have a really stable and fast reaction to applying different loads. The trick was to decrease the standard sample time of the PID algorithm from 200ms to 5ms. There's no chance to bog that spindle down by hand even at 500rpm. The oscilla...
by aam
Wed Jun 10, 2015 12:49 pm
Forum: Member Projects
Topic: PID Closed Loop Spindle Speed Control for Quiet Cut Spindle
Replies: 11
Views: 12532

PID Closed Loop Spindle Speed Control for Quiet Cut Spindle

I'm currently tinkering with a closed loop speed control for my 400W brushed DC Spindle motor. Thought perhaps somebody is interested and eventually wants to join me figuring out some issues that still are causing problems. So here's my setup: IMG_0717.jpg IMG_0718.jpg Photo_diode.png As you can see...
by aam
Sun May 17, 2015 11:48 pm
Forum: Software - CAD, CAM, Workflow Help
Topic: Designing & milling PCBs with free software
Replies: 1
Views: 551

Designing & milling PCBs with free software

I've made a step-by-step tutorial about my PCB designing and isolation milling workflow using only free software.
You can find it here: http://www.instructables.com/id/PCB-des ... sing-free/
Hope it helps! :D
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