Qidi Tech 1 - Replicator 1 clone

[jfkansas]

It actually isn't too bad, but the Creator Pro has a more solid Z axis and platform. Really, that so far is my only concern, but it is a big one because of how flexible the guide rods are. It is silly how easy it is to move the build plate from side to side especially when the platform is in the middle of the travel. I'm not too fond of the metal side plates, but I suppose they will be ok.

Note also that flashforge extruders and thermocouple will not fit the Qidi. The Qidi uses a slightly bigger diameter thermal barrier, and the thermocouple has 5mm threads instead of the 4mm threads on the Flashforge.

[mtnride]

Thanks, yes, the bed is the biggest problem I see, too. I'm playing around with that this weekend. I doubt I'll find an easy solution but maybe there's something to be done there. Despite its flimsiness it seems to hold level for a very long time and the ringing on direction changes isn't bad and can be dialed down with software. Hoping to try some hardware solutions.

[rcleav]

=
Note also that flashforge extruders and thermocouple will not fit the Qidi. The Qidi uses a slightly bigger diameter thermal barrier, and the thermocouple has 5mm threads instead of the 4mm threads on the Flashforge.

I have a Qidi bought around Nov. 1, 2015 and it has 4mm thermocouples. They went to the larger thermocouples last december in there latest update. They seem to roll in improvements to the machine several times a year.
I don't really think the thermocouples being a different size makes much difference unless you have multiple machines with the smaller size.
Also check Qidi ebay store there parts can be bought at ridiculously low prices that Flashforge will never match.

[jfkansas]

Thanks, yes, the bed is the biggest problem I see, too. I'm playing around with that this weekend. I doubt I'll find an easy solution but maybe there's something to be done there. Despite its flimsiness it seems to hold level for a very long time and the ringing on direction changes isn't bad and can be dialed down with software. Hoping to try some hardware solutions.

I have this designed, getting pricing this week.

QidiZ v9.jpg

[jfkansas]

I have a Qidi bought around Nov. 1, 2015 and it has 4mm thermocouples. They went to the larger thermocouples last december in there latest update. They seem to roll in improvements to the machine several times a year.
I don't really think the thermocouples being a different size makes much difference unless you have multiple machines with the smaller size.
Also check Qidi ebay store there parts can be bought at ridiculously low prices that Flashforge will never match.

Part of the problem with the Z axis is how weak the rods are intstalled in the bottom mounts. The Flashforge plastic mounts are stiffer and more material around the rods, even back when they used 8mm rods...

On the Qidi, it might be possible to use a solid resin based epoxy and fill in the cups a the bottom of the z rods. This will help stabilize them. Right now they are like a fence post in a hole that hasn't been filled in.

[mtnride]

Part of the problem with the Z axis is how weak the rods are intstalled in the bottom mounts. The Flashforge plastic mounts are stiffer and more material around the rods, even back when they used 8mm rods...

On the Qidi, it might be possible to use a solid resin based epoxy and fill in the cups a the bottom of the z rods. This will help stabilize them. Right now they are like a fence post in a hole that hasn't been filled in.

I tried a less permanent version (see photo - there is a mirror version on the other side). It makes some improvement in ringing on a box test structure, so I think further improvements with either a better printed part than my sketch, epoxy or a redesign will help.

supports.jpgIMG_4667.jpg

[DJalin1]

I tried a less permanent version (see photo - there is a mirror version on the other side). It makes some improvement in ringing on a box test structure, so I think further improvements with either a better printed part than my sketch, epoxy or a redesign will help.

supports.jpgIMG_4667.jpg

Where can I get the model for this fix?

[jfkansas]

Ringing like that generally isn't from Zaxis wobble or movement. But ya there is a little less on the right one.

I tried a less permanent version (see photo - there is a mirror version on the other side). It makes some improvement in ringing on a box test structure, so I think further improvements with either a better printed part than my sketch, epoxy or a redesign will help.

supports.jpgIMG_4667.jpg

[mtnride]

Agreed, most ringing should be due to xy gantry issues. Ringing like that can come from a bad interaction between the xy gantry and build plate... that is the aim of the fix. Since the whole thing is stupidly open loop (like most 3d printers or gantries) better mechanical design can help. This could be shown or disproved by putting IMUs or other sensors for better position sensing on both the extruder assy and the build plate to look at phase differences in their oscillations (this would also bypass the need to generate test prints to test hypotheses)

[jfkansas]

I would expect more layer over layer registration issues with the z axis having lateral flex like that. The thing is you probably wont notice it until you are in the middle of the Z travel. Items over 50 - 60mm tall should show the effects. Then as the build plate gets closer to the bottom they would go away somewhat.