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Grease pump
« on: February 20, 2011, 09:22:08 AM »
I need some help with my auto lubricate system to set it up in mach3. I will need a output to go on and off for a specific set of time on every 50 meters of travel to activate my grease pump system. Is there a way to do it in brains and how. Thanks.

Peter

Offline djc

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Re: Grease pump
« Reply #1 on: February 20, 2011, 10:33:44 AM »
...I will need a output to go on and off for a specific set of time...

....on every 50 meters of travel to activate my grease pump...

I think it is quite difficult to keep track of time as such within Mach. If you want to involve Mach at all, it would be much easier to pulse an output that switches the pump on and sets a timer running. The external timer then switches the pump off after the correct period. A 555 could do this no bother.

How do you propose to measure the distance of travel? How does the 50m accumulate? If the machine does a 1m rapid and then 11 back-and-forth 100mm moves, does the total equal 1.1m or 2.1m?

Again, a 555 might be good: just count the pulses on the step line, work out how many pulses equals 50m travel and trigger your output (which is the input to the second 555)

See http://ecelab.com/circuit-frequency-divider.htm

Cost so far: two 555s (or one 556) and a relay.

You could combine both on an Picaxe 08, but you still might need a separate divider in front of it as the Picaxe won't count at 25kHz.
Re: Grease pump
« Reply #2 on: February 20, 2011, 02:04:53 PM »
How do you propose to measure the distance of travel? How does the 50m accumulate? If the machine does a 1m rapid and then 11 back-and-forth 100mm moves, does the total equal 1.1m or 2.1m?

I think the total distance should be 2.1m. The rapid moves should also be counted.
Re: Grease pump
« Reply #3 on: February 20, 2011, 05:48:01 PM »
Given the complexity of the task, and the relatively low cost of grease, I would be tempted to impliment a simpler solution - Pump once on startup, and once more for every 5 minutes of spindle running time (or however long usually approximates to 50 metres of slide travel. Is this worth considering?
Re: Grease pump
« Reply #4 on: February 20, 2011, 06:07:36 PM »
Hi,
yes that would also be worth considering. Can you please tell me how to do it? Thanks.

Peter

Offline Hood

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Re: Grease pump
« Reply #5 on: February 20, 2011, 06:11:49 PM »
Do a search of the forum for auto oiler and you should find some info as it has been done a few different ways if I recall.
Hood
Re: Grease pump
« Reply #6 on: February 21, 2011, 05:05:20 AM »
Thanks Hood I will take a look.

Peter
Re: Grease pump
« Reply #7 on: February 21, 2011, 09:51:17 AM »
This would be very easy to do as an external process.  You could use a PLC and an encoder or if you wanted to apply some backyard engineering, you could use an Arduino and a photo sensor and black wheel with white line as an encoder on the drive motor.  You don't need a high resolution encoder for something like this.  Two counts per motor rev is probably enough.  You don't need to oil the bearings at exactly 50m down to the thou.  If it's a few cm off either way it won't matter too much.

All you'd need to know is the number of counts per meter...of if you use a high res encoder, you could track mm and set your oil point at 50,000mm.  The logic would be simple.  Just keep a running total and when it hits the set point, trigger a relay for a few seconds, clear the total and start over.
Re: Grease pump
« Reply #8 on: February 21, 2011, 02:43:13 PM »
Hi, yes that could also be possibility but in my case not because I don't have any output shaft to mount the encoder or black wheel. I use servos and rack and pinion drive and there is just 2mm of space between pinion and table. Thanks again for the idea.

Peter

Offline djc

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Re: Grease pump
« Reply #9 on: February 21, 2011, 03:24:13 PM »
...I use servos..

Which ones? Post a link to the manual please.

Most high end servos (Mitsubishi, Yaskawa) can _output_ a pulse stream that is a an multiple of the input pulse stream. This multiple can range from maybe 2^15 to 2^-15. If your servos do the same, this would be ideal for triggering your oiler.