Belt Anchors

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OK. The belt anchors aren't the sexiest part of the ShapeOko. Use the default configuration to get your ShapeOko up and running. Then, use one of the designs below to create your own, better belt anchor.
Belts 5.JPG

Makerslide Belt Clip

Please note that a new belt anchor design was created for future iterations. See Makerslide Belt Clip.

Some users have reported clearance difficulties (V-wheels stopped by new on-rail belt clips?), w/ BotDoc trimming his down. Catalin Voinescu addressed this by creating similar Buckle-type Belt Anchors which are narrow enough so as not to interfere.

Jacob32123 made narrower replacements using 0.02" aluminum: Narrow Belt Clip (includes SVG).

One concern is that the limit to the travel prevents the wheels on the underside of the X-Axis Carriage fouling on the wheels on the top of the Y-Axis, presenting a potential issue when full-travel is made possible on the X-axis.[1]

Arrangement of the belt: [2]

Note that this has since been changed, the suggested technique now is:

  • in from the bottom
  • over the center bar
  • down near the vertical connector
  • back under

(basically just turn over the above image)

Shapeoko 3 belt clip

An L-shaped bracket w/ cutouts for the belt.

S3 - belt clip.jpg

Further details at: or see the assembly instructions for the Shapeoko 3. Note that since Summer 2016 that the SO3 belt anchors now include a PEM nut for tensioning.

Note that routing is somewhat subject to user vagaries as one can see in the images for Tim Foreman’s limit switch kit: --- the exact routing doesn’t matter so much as ensuring that the belt is held tightly so that it doesn't move.

Alternative usage

One option for addressing this is to move the clips to the outside of the end plates and pull the belt through: Re: V-wheels stopped by new on-rail belt clips?.

A further iteration would be to also add a bolt and nut as in Quick and easy Y-axis tensioners.



Created by: T4b

Upgrade Name: Washers

Description: Belt anchors made by only adding four big washers to the stuff already used for the default belt anchors.

Status: Fully functional

Materials: 4 big washers


The only non-obvious thing might be that to tension the belt further it's a really good idea to loosen the belt mount brackets a little, install the belts (tightly) and then tighten the belt mount brackets again.

Ideally, you would use washers a little bigger the ones I had lying around.

I guess it's quite similar to the zip ties method, but for some reason I like it better than zip ties.

Kosme Belt Clamp


Created by: User:Kosme

Upgrade Name: Kosme Belt Clamp

Description: Proposed belt clamp design


Materials: 7mm UHMW or HDPE



Link to a proposed belt clamp design. It was designed in Sketchup and the gcode generated with Phlat Script. To use it, remove the current belt clamp and the two screws holding the rail to the end plate, put the screws through the holes in the new clamp and re-screw them to the rail. Run the belt between the two top holes and pinch it using the current belt clamp, two screws, and two nuts.

22/02/2012 New Gcode for rounded edge on 7mm thick T shaped clamp.

DrRob Belt Anchors


Created by: User:DrRob

Upgrade Name: DrRob Belt Anchors

Description: Belt anchors made from short right-angle aluminium strips

Status: Fully functional

Materials: Right-angle aluminium strips


Construction details can be found here: DrRob's belt anchors.

Successful Implementations

Hardware Store Alternative

In forum post Re: ShapeOko #200 from inventables batch user alpha suggested, "2 packs of corner braces from Lowes (Stanley S838-946 / DPB113 plus 10-32x1/2 combo round w/nut 10 Pcs) instead of fabricating my own".

Zip ties for belt anchors

One concern is that zip ties may be adversely affected by heat, or heating up caused by direct sunlight.


Created by: User:potatotron

Upgrade Name: Zip ties for belt anchors

Description: Proposed belt clamp design

Status: TESTED

Materials: Zip ties

Source: potatotron zimmer62



I used zip ties to secure the belts and it seems to be reasonably strong and since the belt's teeth are holding itself in place I don't think it will slip. I loosened my belt mount brackets, did the zip ties and then tightened down the brackets to add some good tension to the belt.

Successful Implementations

Alternate Implementations

An alternate technique using two different sizes of zip ties, allowing for on-going adjustment is shown here in this forum post: Cat's ShapeOko (#709)

Another technique is to run the belt through the hole, around some round object or peg and then back along itself. This can be extended so as to help hold the machine together as seen in: Wfa_shapeoko_ziptie_cable-mgmnt_mk-iii.JPG ---

Tobs Belt Anchors


Created by: User:Tobs

Upgrade Name: Tobs Belt Anchors

Description: Belt anchors made from two pieces of aluminium

Status: Functional

Materials: 25mm wide and 8mm thick aluminium bar (cut into pieces of 70mm and 10mm)

Each belt anchor consists of two aluminium parts, a small clamping part (A) and a larger part to mount on the machine (B) (see drawing below). The holes on part (A) are normal holes, whereas the ones on the top of part (B) are threaded to fit an M5 screw. In addition, four M5 x 16 screws are needed. Two to mount the belt between the two parts and two to mount everything to the machine.


Friction fit belt anchors made of starboard

Shown on the forum post Re: Another Red Shapeoko. Next post down includes G-code to cut out of 12.7mm (half inch) material.

Another friction fit design is shown in HTD3M belt-tensioner.

Or: Belt Clamp for OrdBot.

Eye Bolts

Forum member bubblehead "...used an eye bolt to adjust tension. I'll probably add a locking nut so it doesn't loosen." Re: Belt anchor with adjustable tension

A 3/16" x 1-1/2" eye bolt (rated at 65 lbs.) seems a good fit (~$1.39 ea. @ True Value). Add a wing nut and washers (at least one locking washer) for easier adjustment.

N.B. - only one eye bolt is needed per belt --- position it at the end where it will least affect the gantry.




Forum user microwavesafe moved his Belt on outside.

Printed Belt Anchors

A number of designs for this have been uploaded to Thingiverse:

And others to the forums:

eShapeOko Belt Clamps

A Belt Clamp Set is available from MakerSlide Europe, SU010

Electrical connectors as belt anchors

Forum user xtonyx found these Blackburn #2/0 Stranded Max Type-ADR 2-Conductor 1-Hole Mount Dual-Rated Wire Connectors (2-Pack) at Home Depot and decided to use them for belt anchors in his machine: Tony's ShapeOko #1894F.

Cpt Kirk's - Hacked shapeoko - Build Log --- shows two different options.

Inverting Belts

A frequent additional change when altering belt placement is to turn them over to keep debris out of the teeth: Another Belt Configuration