Bed Alignment Jig by kmxsoft

Last crawled date: 3 years, 1 month ago

This thing provides simple and very easy-to-use bed levelling. Loosely based upon ideas presented in thing 62553 ('The Calibrator'), this design uses a Digital Dial Indicator such as this:
https://www.amazon.co.uk/gp/product/B01H035DRO/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
Also available from:
http://www.harborfreight.com/1-inch-sae-metric-digital-indicator-93295.html
Note there are a range of prices for these digital indicators - we don't need supreme accuracy so expect to pay in the region of $20-$30.
You can interface the dial indicator via a USB connection according to the following instgructions:
https://hackaday.io/project/511-digital-dial-indicator-cnc-surface-probe
This thing should work on any 3D printer based upon the Makerbot 2 design.
In implementing this thing I now have a very simple means of adjusting bed levelling. No more moving the head around and trying to gauge height by sliding a piece of paper under the nozzle - just set one height point then move this thing around to set the same height across the table. Bed levelling takes just 2 minutes and the result is a bed which is levelled more accurately than using a piece of paper.
In order to create this thing you'll need some extra's:
4x N38 Round Rare Earth Neodymium Magnets 12mm x 3mm With 3mm hole.
20x M3 Flanged Rivnuts (sometimes called 'nutserts').
4x M3 10mm countersunk bolts.
2x M3 20mm bolts.
1x M6 50mm bolt and nut.
If you don't have rivnuts you can print the sled 'with nuts', and use M3 nuts instead. Rivnuts are definitely better though.
ebay is your friend if you need any of the above.
Using the thing is straightforward. Note that we aren't interested in setting a particular height - we just need all points on the bed to be the same height:
1) Set to home position - bed raised, nozzles in north-east corner.
2) Set bed height in one corner using traditional paper-between-nozzle-and-bed method. This gives you the reference height used by all other levellings points.
3) Slide the nozzles to the right (maximum X).
4) Slip this thing onto the rails - it will hold firmly with the rare earth magnets but can be slid on the X axis. Slide indicator over the point set in (2) above.
5) Zero the dial indicator.
6) Move dial indicator over each adjustment screw and wind bed up/down to set zero on the indicator.
That's it! Bed is levelled and you should get perfect prints!