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jcrocholl / kossel

Mini Kossel portable delta robot 3D printer.
http://deltabot.tumblr.com
GNU General Public License v3.0
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Endstop switch does not touch screw on slider #10

Closed brandonheller closed 11 years ago

brandonheller commented 11 years ago

Anyone else have this problem? I'm using a SHCS on the stock slider, with ball rails.

Of course it's an easy fix, shifting the holes on the endstop piece or increasing its thickness or moving the hole on slider over, but I'd like to verify that there isn't something obvious that I'm missing.

jcdoll commented 11 years ago

I have the same issue that you do - the hole at the top of the carriage would need to be offset to use a screw head to trigger the switch.

It looks like Johann is leaving that hole empty: http://www.flickr.com/photos/jcrocholl/8983596437/. I suppose that with auto bed leveling, fine control of the endstops becomes moot.

On Wed, Jun 12, 2013 at 8:57 AM, Brandon Heller notifications@github.comwrote:

Anyone else have this problem? I'm using a SHCS on the stock slider, with ball rails.

Of course it's an easy fix, shifting the holes on the endstop piece or increasing its thickness or moving the hole on slider over, but I'd like to verify that there isn't something obvious that I'm missing.

— Reply to this email directly or view it on GitHubhttps://github.com/jcrocholl/kossel/issues/10 .

brandonheller commented 11 years ago

That makes sense - when you have auto-leveling, the screw just removes Z travel.

I'd still like to add the adjustable endstop to compare against auto-leveling, so I think I'll make and then send a slightly offset carriage hole. The pulley is ~10mm and the SHCS head is ~5mm, which gives the 2mm or so of motion needed for them to match up.

Joey, are there any other issues you've come across? Sounds like you're close to done, too.

jcdoll commented 11 years ago

I have a few smallish issues written down that I will add to github eventually. My build is getting there and I hope to have effector movement this weekend, although there is still a long ways to go.

One question for you actually - I saw your Cerberus carriage adapter photos and it looks like you closed your belts with zip ties. Did that work out okay or did you end up modifying the carriage design? I'll be using an open belt because I went for a slightly larger frame (360/720mm extrusions) and I wanted the length flexibility.

On Wed, Jun 12, 2013 at 9:55 AM, Brandon Heller notifications@github.comwrote:

That makes sense - when you have auto-leveling, the screw just removes Z travel.

I'd still like to add the adjustable endstop to compare against auto-leveling, so I think I'll make and then send a slightly offset carriage hole. The pulley is ~10mm and the SHCS head is ~5mm, which gives the 2mm or so of motion needed for them to match up.

Joey, are there any other issues you've come across? Sounds like you're close to done, too.

— Reply to this email directly or view it on GitHubhttps://github.com/jcrocholl/kossel/issues/10#issuecomment-19339335 .

brandonheller commented 11 years ago

I didn't actually test motion with the ziptie closures, as you need a complete frame to prevent a singular frame_top tensioner from twisting down under load, and I didn't have that a few weeks ago. Motion is next for me too.

I think zipties to secure the belts would work fine, but the zipties might compromise a bit of Z or create an interference. The next ball joint adapter I print will integrate a tiny tensioner and use printed slots that are a negative of the GT2 belt profile. I used this technique for tensioning my PBJr (XL?) belts and it works great. No zipties makes it faster to install and adjust, and since the belt will be under tension, backlash in the negative profile doesn't even matter.

I also think an open-belt option is the way to go, for the flexibility you get.