A few weeks ago I got the new drawmodule for Elekslaser A3.
Either I am not able to assemble it properly or the design is a fail. It is even worse than the penholder
of the Eleksdraw which has the same issues.
The main problem is that there are two shafts with two brass sliders.
There has to be a very high precision for this to work properly, but the design
from Eleksmaker has to much play. Just look at how the shafts are fixed (or rather not fixed).
As a result there are some issues.
If I tighten the screws of the brass sliders, the penholder tends to get stuck somewhere on its way
or won't move at all because it is impossible (at least for me) to keep the two shafts and the two gliders
absolutely parallel. Perhaps it is possible to play around untill you find the perfect fit, but I couldn't
manage to do this so far. Even if you do, it won't stay like this because the two brass sliders are
fixed only with one screw each. So at the latest when you change the pen and use a little force it will
If I don't tighten the screws too much or let them loose, then the penholder might move properly,
but it has to much play.
For example when I let the machine write the same word with a one stroke font two times at the same place
the lines won't match. Also the result of writing with two stroke fonts with a fine pen is very poor.
A solution could be the way how laser mechanisms for cd-players (like the KSM-210 or KSM-213) are designed.
They have one fixed shaft with two small brass gliders. This stabiliezes the laser in two axys.
For the third axys there is an open (u-shaped) slider with a small contact surface instead of a second
long brass slider like in the Eleksmaker design.
With this the laser can move freely and has almost no play. No adjustment needed.
As I have usually some old mechanisms lie around I tried to make a drawmodule myself.
Here is the result. As you can see I used some parts of the original drawmodule.
Inspired by this design I decided to improve the Eleksmaker drawmodule.
I CAD designed and 3D printed an u-shaped glider. I made two different designs but when I tried them
both of them worked the same.
I had to print the gliders three times with diffrent scales. 100% was too loose.
96% had to much friction but I could have used it if I added a spring on the shaft to push the pen down.
(A spring is also usefull if you use pens which need a little pressure to write properly.
Another method is to add some weight.)
But as the printtime for such small parts is short I tried a scale of 96,5% and it turned out just perfect.
I removed one of the brass sliders and drilled an additional hole for my u-shaped glider.
Also I drilled a further hole for the remaining brass slider. It is now attached with two screws.
The improvement is amazing. The pen slides up and down easily and it doesn't matter how the shafts
are tightened (paralell or not, tight or loose). This solution works also for the Eleksdraw.
The play of the mechanism is now depending on how much the shafts can move and the precision of the
u-shaped glider and the brass slider.
As the brass slider is quite good and the u-shaped glider was finetuned the only remaining issue
is the movement of the shafts. The holes for them are quite big and the rubbercaps give no stabilization
at all. For the first try I just hotglued them.
A more professional solution would be to cut threads in the ends of the shafts and screw them down with a
If the nut is conical on one end (I used the self-locking one with a rounded side) it could be screwed
upside down into countersunk holes to center the shafts and to give even more stabilization.
Another idea is to use a plate with two conical holes to fix the shafts.
The plate is fixed to the mounting plate with a screw in the middle of it. Two plates are needed, one on
each side of the shafts. Don't forget the brass glider or you will have to dismantle it again (like I had to).
The conical holes are holding the shafts centered and the screw applies pressure
to fix them. The shafts can stay as they are or they can be shortened a bit to make the drawmodule more compact.
I'm not sure if I can upload the .stl files for the gliders and the shaft holder. Something uploaded but the a error message appeared that I don't have enough privileges for this action. Perhaps it will be aproved by EleksMaker
[2_1521048647150_shaft holder.stl](Uploading 100%) [1_1521048647150_Gleiter 2.stl](Uploading 100%) [0_1521048647150_Gleiter 1.stl](Uploading 100%)