Advice on project

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1

Hi,

Firstly I have very little electronics or Arduino experience so please bear with me! I'd like to build a device to control the speed of a router spindle. The router has a 1-10v speed control which also need an 8v input. Below is some information on the 1-10v requirements.

router 1-10v
router 1-10v863×793 292 KB

router speed
router cable

The 1-10v control is via the PV interface which when powered by 8v (min) will change the PV interface to Portal mode - i.e. the 1-10v speed control mode.

I'd like to control the router speed via a potentiometer and also have a display showing the xxx based on 0v being 4000 RPM and 10v being 25000RPM and each 1v increment increasing the RPM by 2100.

The area that I can't get my head around is that the potentiometer will need a 10v input, the router controller needs an 8v input but the arduino works with 3.3 or 5v.

Can anyone point me in the right direction please?

Thanks

2

So you want to read the potentiometer voltage? Use a voltage divider.

3

Great, so I would use this to read the voltage between the potentiometer and the router and send back the voltage (divided) to the arduino for display.

4

@cetojames
What do the three different lines on the graph represent?
Which arduino do you plan on using?

5

If you start with a 12V power supply, you can connect that directly to an UNO and the onboard regulator will bring it down to 5V.

Then get a 50K potentiometer and connect it in series with an 8K resistor
[12V to 8K to 50K to GND]

The connection point between the pot and the 8K will be 0-10V and this can connect to Us.

Also connect that point to two 100K resistors in series to get a voltage divider that you can feed into your UNO for a 0-5V signal.

[Upv to 100K to 100K to GND]

Finally, connect the 12V power supply directly to Upv to make the router be in Portal mode.

6

It's just the bottom line that counts - it's the spindle RPM

7

Thank you very much! Can I use the same 12v power supply for both?

8

OK so which Arduino are you using.
We don't want to blow-up your new Arduino.

9

I was thinking of the Arduino Nano Every.

10

I was thinking of the Arduino Nano Every.

How accurately do you want to control the speed.
Would +/- 50 RPM be good enough?

11

Yep. I 12V power supply will do the trick.

12

That variance is fine tbh

13

Is there input resistance for Us stated in the documentation or maybe the drive current.
Is there an upper limit or tolerance given for Us?
We don’t want to destroy your machine.

14

I'm not sure if this will help:

image
image515×538 77 KB

Manual

15

OK, thanks for the manual. They only state that it’s protected from reverse polarity.
So it may work with a pot but to be safe, I would make sure that the 10V is within +/- 5%

However, when using a pot, you may find it difficult trying to set a particular speed and having it remain steady as you work. For example, if you had a 25mm diameter knob on the pot, rotating it just 1mm would result in a speed change of 357 RPMs. You may need to fiddle with it all day just to set it to 10000 RPM. I don’t know if that is acceptable or not.

16

Really appreciate the information, Jim. Any alternatives that would make setting RPM RPM easier and less prone to movement (the router will cause vibration)?

I was looking at a Rotary encoder but don't want the dial to rotate 360 degrees or more. This would also mean I would need to go from 0-5v to 0-10v somehow.

What would be great is a potentiometer that has free movement but has 'clicked' positions at 10% intervals.

17

Why no more than 360?
You spin the knob until the display shows close to the RPMs you want, then to get precise control you turn it slowly.

This would also mean I would need to go from 0-5v to 0-10v somehow.

Well you use a 10V DAC connected to the Nano, that way you can use an encoder or even two pushbuttons for increase/decrease

18

Sorry Jim, it's going a bit over my brain pay grade! A potentiometer is simple in my head because turning to a position will change the voltage output with a set 'High' and 'Low' being the clockwise and counter clockwise limits. With a Rotary Encoder it just seems like an increase or decrease voltage mechanism rather than setting to a specific voltage.

19

I understand. Since you will be the one that will be building this and writing the code, it’s your choice. The rotary encoder set-up and the associated code will be more complicated than just using a pot.

20

Mathias Wandel does amazing woodwork and general experiments. Here he compares variable speed routers and variable power supplies...