Hey thank you. So here is a link to the limit sensors I bought plus a breakout board. I really like the idea of these things because there are no mechanical parts to wear out. He says I can also encapsulate the sensor and the magnet and will not hinder their performance. I saw a post on inventables where a guy with a Shapeoko used them.

Creltek Limit Sensor 343RT by Kevin H. Patterson on Tindie

 

I've already bent a couple of my limit switch arms on accident plus the mating surface usually ends up with chips and sawdust caked on so who knows how repeatable my current setup is.

 

Thanks Pat! I'm really enjoying working with this HDPE. It's a blast.

 

I got some new Ebay items to play with too Ball ball end, 1/16" flat and some 90 degree engraving bits. I'll let you guys know how it goes.

 

The covers slip over the wheel bolts but those bolts also need room for adjustment of the eccentric spacers. These are also a fairly loose fit so they can be adjusted up and down a little. From what I have observed, very little chips will actually make it through that gap. Yeah there will be some and I will have to to remove the covers and clean occasionally but they will reduce a significant amount of dust / chips. For the most part I saw the chips shoot up at an agnle, hit the gantry plate and fall on top of the wheels. I knew I needed to leave a little room for eccentric adjustment so I think I left a 2mm gap. If anything, I can mill an HDPE strip for the bottom.

 

The end caps are fairly loose fit too and can be adjusted up and down a little.

 

Future plan is to implement linear rails somehow but I haven't figured it out yet

 

Yeah actually that would probably work very well. Plus I wouldn't be rubbing two pieces of aluminum together. Great idea Pat, thank you.

 

That piece of aluminum in my last post is for some long strips to cover the side of the Y axis Cbeams. They seem to really load up with chips and they don't come clean completely with the vacuum.

 

I'm really just trying to "tighten up" my machine so I don't have to worry about all these other factors when running a job

 

Yeah the wheel covers are mostly a WIP but I just didn't want to go the route of attaching a piece of plastic the length of the y axis. Currently they will keep the material from falling down on the wheels and they will plow shaving out of their way in the vslot grooves.

 

Limit sensors arrived today, a day early!! Very nice little setup. 12ft cables pre-crimped with RJ45 connectors for the breakout board. The neodymium magnets are in the steel tube.

 

Sure no problem Pat. My X axis cbeam is 503mm and my Z axis is 270mm. The original Sphinx plans call for a 250mm cbeam for the Z but really this can vary and I have seen people go all the way up to 350mm even though I don't think it's necessary. I just decided to make mine a little taller just in case.

 

As long as your spindle & bit can completely clear your workspace you should be good. Are you using a router?

 

Oh pat in case you're wondering why the X axis is 503mm and not 500mm is because each side of the gantry has a 1.5mm gap to allow for movement.

 

Working on mounting brackets for the sensors. I'm really excited about this because there is no need for physical contact between the sensor and the magnet. I just need to make sure I orient the magnet in the right direction. I can basically enclose the whole thing. They do have status LEDs so in the future I would like to replace the plastic caps with acrylic or something.

 

These sensor brackets span 80mm across the cbeams and bolt right through the vslot. i'm currently trying to figure out a solution for the magnets. They're actually really strong!

 

That's a good idea. If or when my res pump dies, I could definitely rig something up! Thanks.

 

Yes I spoke with him prior to ordering the setup. The sensors operate at 3 to 6 VDC but he offers different arrangements for the breakout board. I went with the one that operates on 12 VDC and will be utilizing an extra cable from the control PC's PSU.