Microswitch accuracy

[Speedy Builder5Participant @speedybuilder5]

I have an ELS from Electronicleadscrew.com and am very pleased with its capability as installed on a Boxford AUD lathe.  It has an option that I haven’t used but am keen to set up the “limit switches”.  These are usually microswitches, however they stop +or- a few thousands of an inch.  Are there such things as “precision” microswitches.

Bob

[JasonBModerator @jasonb]

Not sure of that particular ELS but the one I used you set lengths by entering them in the keypad and the ELS took care of stopping in exact positions.

 

Are the limit switches more like you get on a powerfeed and just turn the feed off if you get to the end of safe travel? Same with a CNC the limit switches are at the extremes of travel to save a crash.

[mgnbukParticipant @mgnbuk]

Yes – from Balluff and Euchner to name two + IIRC Omron also do them.

Available as singles or ganged as multiple switches in a common housing & used for CNC machine tools

Used the first two mentioned & IIRC the switchpoint is repeatable to within a thou. But ….

…. these are precision industrial items and they are not cheap. Also require the matching hardened trip dogs.

Euchner distributor used to be in Sheffield. Catalogue on their website is “Precision and multiple limit switches” in the Downloads section.

Balluff switches are here : https://www.balluff.com/en-gb/products/areas/A0001/groups/G0113

If you can identify the type of switch you want they do come up on Ebay at less scary prices. IIRC the chisel point type plungers are more repeatable than the roller tip type.

Nigel B.

[MacolmParticipant @macolm]

Look on the Honeywell website for precision microswitches. I seem to remember these are good for 0.025mm or better stability, though subject to quite a few to specific mechanical and electrical conditions to achieve this. Don’t be surprised if the cost is similar to your lead screw, though I could be wrong about that.

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