It surprises me that, after more than a week, nobody has commented on my last post on the subject of leadscrew accuracy - see viewtopic.php?f=53&t=12907
I am very interested to know how the new K8204 compares - has anybody installed one yet?
Wally
Hi!
My K8204 Kit just arrived and i mounted it following the Instructions.
Looks not so bad, but i will seriously change the mounting, so it goes top down, with hanging z axis.
That micht even allow to get some extra Z travel than with the original motor mounting
as the leadscrew is only 300mm in length.
What i don’t understand is why the velleman instructions for the k8204 say to upgrade the firmware.
[quote]INSTALL THE NEW MARLIN FIRMWARE K8204 • INSTALLEER DE NIEUWE MARLIN FIRMWARE K8204 • INSTALLER LE NOUVEAU MARLIN FIRMWARE
K8204 • INSTALLIEREN SIE DIE NEUE MARLIN FIRMWARE K8204 • INSTALE EL NUEVO FIRMWARE MARLIN K8204[/quote]
What else other than the Z axis steps/mm is changed in that firmware?
Could you post a picture of a project with the stock lead screw and one from the new one?
Well, that would mean i have to remount the M8 rod…
But i’m curious for a direct compare too.
I think i really remount it and print some simple parts for direct compare.
What i can say right now is that the layers printed in 0.25mm now look as smooth as before only with 0.1mm. Very even and exactly in height.
Next mod will be exchanging my wobbly x and y axis belt pulleys and go for a GT2 2mm Belt drive with 16 teeth pulleys.
I just decided to do it.
I’ll print a simple hollow square 50/50/50mm in .25mm layer height.
First print is running with the K8204 leadscrew update, mounted according velleman instructions.
Next i will remount the original M8 rod and run another one for direct compare.
Thaks for the effort.
I’m also curious to see the comparision between the two.
I’m still waiting for my K8204 kit…
Your idea on mounting the Z stepper on top and supporting the flex coupler sounds very interesting.
Regards
/R
Second print is already running, i’ll post pictures of the results in about half an hour.
Whoops! I had to restart the second print. Forgot to set back the correct steps/mm for the Z axis… Ö
Ok, testprints are done!
Object :
Hollow square sliced with cura engine
w/d/h 50/50/50mm 0.8mm wall thickness 0.25mm layer height
Printed with the original M8 rod but upgraded mount :
(flex coupler and M8 rod fixed by upper bearing)
Result measurements after cooling down :
dimensions :w/d/h 49.57/49.54/49.83mm
walls : 1.09- 1.10mm
Noticable vertical pattern in the layers at about ervery 12-15th layer
Printed with the K8204 leadscrew upgrade :
(same flex coupler not the one in the kit otherwise mounted as instruction says)
Result measurements after cooling down :
dimensions :w/d/h 49.96/50.05/49.97mm
walls : 0.91- 0.96mm
vertical pattern in the layers completely gone
(the slight remaining horizontal layer shift is likely caused by the inconcentric “wobbly” X and Y belt pulleys
The result ist not quite that much better cause the flex coupler and fixing the M8 rod at the top already were a great improvement.
But compared to the original stock components it is way better.
Also the leadscrew upgrade reduced the Z axis backlash to near zero.
judge for yourself …
cheers Christian
Hi Chris
That looks very good indeed. A big improvement.
Can’t wait to get my kit.
Again, thanks for the effort!
Regards
Rainer
Thanks for the pictures
It does look better.
Waiting for it in the USA
I sure wouldn’t mind buying one but it’ll be months if ever before Jaycar sell it here (much like the vertex printer which I wouldn’t mind getting my hands on) and Velleman won’t sell direct…
If this wasn’t a physical product…
Where do you live freman?
Ther meight be other resellers…
Or maybe you could ask them to do a custom order for you?
Hi,
i dont know why but i dont have any wobbling on the Z axis !
am workin with the original hardware, will post some pitcures of my hollow square !
am wondering if i really need to upgrade to the 8204 kit ! it s very expensive for me.
i thinkin to order a trapezoidal rod and a flex coupler from ebay.
chris ?
A leadscrew from ebay will work as good as the Velleman kit i think.
You have to get the parts and fixing done by yourself then.
I looked at your print. (hollow cube)
Looks not that bad at all.
Seems you were lucky with the supplied M8 rod. Most of them come slightly warped and bent, causing wobble on the Z axis.
With a leadscrew you will get better evenly layer height, and more precise layer height as with a M8 rod
because of the much lower tolerances of the leadscrew.
Take a look here :
viewtopic.php?f=53&t=13024&p=57105#p56988
thank s ichbinsnur !
i saw your posts too, greater quiality whith the 8204 !
i ordrer a lead screw (8 300mm 2mm lead) and a copper nut. (3 pieces for each , it’s for XYZ axis xD , can t find 1)
will post the changes after the modification !
Will you put leadscrews on X and y too?
What did you pay for the parts?
not for the moment.
the lead scew is only for the Z axis.
it’s about 22 Euros shipping included ! and 2 E for the flex coupler.
really far from the price of the 8204 x) !
Do you have a link of the seller of the leadscrew set for 22 euro?
Thank you!