February 16, 2026
Description
This is a Router attachment for Dremel tools.
Design Features:
Router cup head diameter is exactly 3 inch to help calculate center point and offsets from tool diameters.
Jam nut ensure that the cup head is concentric with the tool spindle.* and spindle tool is square to work surface
Precision graduations in 0.001" increments for setting your depth on the Cup.
Lines are marked with number every 0.005" on the Cup.
One full rotation of the cup moves the cup Base up or down 0.050"
There are graduation lines on the Barrel every 0.050"
Every Fifth Graduation mark on the Barrel has a number fraction showing at each ¼" mark.
large ergonomic Jame nut locks the cup into place and ensures perfect concentricity with the spindle.
More than one full inch range of adjustment up and down.
Perfect for normal length tools and some extra length tools.
No hardware needed Just print and install on your Dremel
Assembly Instructions:
Remove your finger stop from your Dremel tool by simply twisting it loose and unscrewing it.
Install the large threaded Barrel where the finger stop was on your Dremel
Install the large Crown Jam Nut onto the threaded Barrel with the points facing away from the spindle
Install the C shaped spacer ring with the gap in the C shape aligned with the numbers on the threaded Barrel for viewing.
Install the Base Cup.
Operation instructions:
Loosen Jam nut to allow the Cup to be adjusted to the Desired height.
Rotated the base cup take noted of the number markings on the cup for fine adjustment to set the height that you want.
Also take note of the number marking on the Barrel in addition to the cup number markings to set your over all height.
Tighten The Jam nut down onto the spacer and Cup with out moving the cup to secure your height adjustment.
Set Precise Depth of tool:
loosen Colet Nut on the Spindle only enough that your tool shank will slide when pushed or pulled but still has enough friction to hold the tool so that it will not fall out or move easily from being bumped.
Set the Router cup to Zero or what ever height you want to be your starting depth measurement on the router head.
Tighten the jam nut so that you do not loose zero position on the router cup.
Slide the tool out so that it is slightly protruding past the base.
Set the tool Gently face down on the router cup base so that the loose tool is naturally pushed up into the spindle until the tool tip is at the same level as the router cup.
When the router cup is fully flat against the surface that you set it on the tool tip should be at the same height as the router cup face.
Next carefully position the Dremel and router head on it's side and use a pair of pliers to tighten the colet nut on the spindle to secure the loose tool.
Note: tightening the collet nut may pull the tool up into the spindle a very small amount. so for very precise work verify your tool tip is remaining at your set point by trying to slide a peace of paper under the tool tip, but not under the router cup. set the tool tip on a strip of paper that you slide through one of the cup windows if the paper slips out then you may need to move the cup set point up a small amount. if the paper is held tight then your set point is with in .003" or less of your tool tip height.
Now your tool tip is zeroed to your router head.
from hear you can loosen the jam nut a few turns and adjust your router cup up one half turn 0.025" and make your first cut a t precise depth. and your can measure the depth of cut with depth micrometers to confirm the accuracy of your cut and make any needed adjustments to make your final cut at exactly the depth that you need.
* Keep in mind that the threads on the body of Dremel tools and body geometry are plastic injection molded with unknown shrinkage factor and accuracy, also the high speed ball bearings in the Dremel spindle are known to have 0.001" or more of play, this may need to be taken into account when calculating tool offsets because the spindle will deflect the amount that the spindle bearings allow them to.
if the stiction of the jam nut is to strong at times you may optionally try applying grease to the jam nut face and threads. keep in mind this could also attract dust and require more frequent cleaning of your router head threads.
NOTE: If prolonged heavy use is expected you should print the threaded Barrel out of higher temp filament such as PA-GF or PPA-CF etc. because the Dremel tool will become hot with prolonged use as it would anyway, any one who has used a Dremel tool knows they can get very hot with prolonged heavy use and this will cause the threads around the Barrel to become soft and loose easily unless they are printed with higher temp material.
If the Dremel tool becomes hot the heat will transfer through the front spindle threads to the printed threads that engage with the threads around the spindle on the Dremel tool or what ever brand tool you are using, and the printed threads will become soft and week if they are printed from low temp material such as PLA or PETG, and it is possible to plunge cut hard enough to force the tool up and out of the router attachment because the threads became soft. creating a foreseeable dangerous situation with the spindle still powered on and spinning but no longer secure in the printed router attachment. of course if you are paying attention at all you will probably notice the signs of the heat weakening the attachment threads because the quality an accuracy of the cutting action from your tool will become much worse because it is not retaining the strength to hold the cutting tool in position reliably because the plastic became soft from to much heat.
License:
Standard Digital File License
3D Prince
