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New manual bed-leveling mod for the Makerfarm Prusa i3.

(Right after I finished this mod, I looked online and discovered that Colin at Makerfarm is actually selling a kit to do exactly what I have done.  You may have all the necessary parts lying around your shop – I did!)

One thing that has always bugged me about the Prusa i3 design is the lack of a good way to level the bed along the Y-axis.  Leveling the X-axis is easy, if somewhat tiresome:  Just home the Z-axis at the side of the bed nearest the endstop, adjust until your sheet of paper or your feeler gauge just slips under the hotend, then move the hotend to the opposite side of the bed.  Home the Z-axis again, and twist the threaded rod until the feeler gauge again just fits.  Repeat until both sides are equal, and you’re done.

Trouble is, if your bed slopes in the fore-aft direction, there’s nothing you can really do.  I would assume that on the aluminum-frame version of the i3, once you get it set up, there’s not a lot to disturb it, since aluminum is generally stable.  On the wood version, though, there seems to be some seasonal variation.  Like all wood products, the Makerfarm frame will swell and shrink according to the temperature and humidity in the environment.  As a result, I recently discovered that my print bed was out of alignment along the Y-axis 🙁

Not to be deterred, I reached into my hardware box and immediately found what I needed:

  • 3 m3 bolts, 20mm in length
  • 6 m3 washers
  • 3 sections of spring about 10mm long(these were left over from the Z-axis endstop holder that was one of my first prints)
  • 3 m3 nylon lock nuts

Assembly was a breeze, and the whole conversion took about five minutes, including looking around for parts.

Here are the parts you need, in the order you’re going to use them:

Parts for an adjustable standoff.

Here are the parts you need to make a single print bed standoff. I made three of these. If you wanted to leave one end of your Y-axis static, you could just make two. If you want to make each corner adjustable, you could make four.

Basically, you’re going to just be replacing the nylon standoff that is already between the wood base and the heated bed with the spring and two washers.

Assembled and installed, it looks like this:

This is what yoour adjustable standoff should look like when it's in place.

This is what your adjustable standoff should look like when it’s in place.

I left the nylon insert in place at the corner where the X and Y axes both home.  It gives a single, static reference point, and establishes a “standard” height, so I don’t end up raising or lowering the entire bed over the course of several adjustments.

I placed the nylon spacer next to the standoff to help establish a starting point for future adjustments.  I removed it before I adjusted anything.

I placed the nylon spacer next to the standoff to help establish a starting point for future adjustments. I removed it before I adjusted anything.  This got me in the ball park

I now have a manually adjustable Prusa i3 bed!

As I mentioned earlier, Colin at Makerfarm now has a version of this mod available as a parts kit.  He’s a good guy, and  has done a lot for our community.  If you don’t have these parts handy, please consider ordering from him.  Here’s the URL:

Makerfarm Prusa i3 bed-leveling kit

On the other hand, if you’re stopping by the hardware store already, this represents probably about $2-3.00 us.

Enjoy!

 

 

 

7 comments to New manual bed-leveling mod for the Makerfarm Prusa i3.

  • Dan

    When you say local hardware store, where do you mean? I have yet to find a local supplier of anything smaller than M5, and even then the selection is small.

    • I walked three blocks from my house to an Ace Hardware and got springs and bolts. I got the locknuts in quantity from a locally-owned store called Wichita Feed and Hardware, which is a little more of a walk (maybe a mile). For really strange things, like the really long bolts for extruders, I go to a local fastener supply place (Mt. Hood Fastener). That one is about 3-4 miles, so I usually drive it.

      Of course, this is meaningless unless you live in Portland, OR, USA.

      Most of the smaller metric stuff is available through the RC car industry, so I’d start with hobby shops. It’s going to be expensive there, so you might want to ask if they know of a local bulk supplier.

      If all else fails, Amazon.com.

      Oh, and stay away from the big box places. I have yet to see anything small and metric in anything except those plastic bagged two-packs, and they are absolutely outrageously expensive!

  • Dave

    FWIW – I just ordered a bunch of small metric bolts from BoltDepot.com. Seems very cheap for bulk – about $.05 each or so…

  • Dave

    Regarding the blog – I have the kit installed and in the lower left corner, it tends to pull up the wood bed instead of pulling down the heated bed. I’m replacing the wood with aluminum when the part comes…

  • I have been buying metric hardware from http://www.mrmetric.com mrmetric site. They start out at 2mm and go beyond 12mm. I ordered all my hardware for a printer build in stainless steel. Their selection are many. You want a washer in 3mm well they have four or more types in each size to choose from. My order arrived overnight but I live on the west coast where they are located.

  • Patrick Voelker

    I’m a little late to the party but I found what I needed at Home Depot. The most expensive part was the box of assorted springs.

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