Neje max 4 E80 XXL Extension project

Hi, I’m planning to customize or extend the Extension Kit from
750mm x 1030mm to 750mm x 1620mm.

I will connect (lenghten) the standard green Y- axis aluminum profile to the extension Y-axis profile by making my own custom CNC steel cross connectors + reinforcement plate to strengthen the profile and avoid wobble.

But I would like to know what kind of timing belt is used for the motor? I need at least 200cm, is it GT2 belt?

I will update my progress in this topic.

yes

any progress? I do not need it longer now, but am thinking about a project that would require the longest extension I could get.

It’s the GT2 belt, what’s the progress you ask?

I was asking @Holtwerk how they were doing with attaching rails to each other with the [quote=“Holtwerk, post:1, topic:9351”]
custom CNC steel cross connectors + reinforcement plate
[/quote] they discussed.

Ok update, the person who is CNC milling the extension an reinforcements parts has a knee injury… this person is 3 weeks absent from work… (sigh…)

However, he already made my steel reinforcement parts that connects the rails from the sides.
I also told him to drill M5 holes into the neje rails so that the steel reinforcement bar (as mentioned above) will connect to the rails.

He has assembled these parts and made measurements with the cnc machine: this part alone makes it already a very sturdy construction, but there is a 0.03mm difference in height between the transition between the 2 rails. (Maybe this is not a big issue, can’t test it now)

I’m waiting for the cross connectors to be made (these slide into the rails, I think these custom parts will make the difference in height go away.

My 2meter GT2 belts have arrived.

I keep you updated

see update

I am looking forward to pictures.

Hi there,

I got my modified rails and steel reinforcements bars + cross connectors.

The person that CNC milled the cross connectors did not follow my technical drawings correctly because the cross connectors are a bit to wide / thick. He provided me with only 2 small cross connectors so I can test further, the thickest parts I had to cut off with a power tool.

HOWEVER these cross connector are therefore perfect! Because they are a tight fit, the rails are perfecttly snugged together. The transition between these 2 rails are as good as it gets.

So I only used 2 small cross connectors of length 100mm (one in each rail, on the opposite side of the reinforcement bar)

With the steel reinforcement bars installed and only one small crossconnector on the backside, there is almost no wobble, these rails are now incredibly strong and heavy.

I had to file down the transition between the two rails; there was still a small step from the green rail to the black rail. I used a diamond file and 240-grit sandpaper to smooth it out, and now there is a seamless transition.

I also noticed that the groove where the GT2 belt runs is wider on the green rail. The black extension rail is slightly narrower, which means the motor wheels have to use more force compared to the green rail. So, the transition doesn’t seem even.

When I jogged around with the neje max 4 , this problem doesn’t seem to matter very much… it runs pretty smooth with no problems.

I have yet to engrave and lasercut and perform full tests, but it looks pretty okay so far.
Still concerned about wobble and the transition between the rails, I wonder if I can engrave with stunning detail without seeing a ‘bumb’

My work area is now exactly 750mm x 1610mm

I put my Xtool d1 pro with extension kit inside the neje max 4 for comparison.

Take that, Xtool hahaha

I will update you guys more, if you are intrested…







Hi there, I updated my post. If you’re still intrested

Yes, Thanks!


Trying out the extended frame.

The black extension rails are slightly thicker than the standard green rails. This creates an issue where I need to adjust the wheels to allow the laser to move more smoothly on the black rails.

I noticed that engraving or cutting on the section of the black rails is not 100% accurate, as the Y-axis falls short. The X-axis, however, has no issues. This is caused by the tightness between the black rails and the wheels. When cutting a square, the square does not close properly.

On the other hand, the laser head moves very smoothly on the green rails, so I’m concerned that loosening the wheels might introduce some wiggle or instability in the laser head’s movement.

Adjust the Y-axis wheel, which is controlled by the eccentric nut

Yes I know, but what if the wheels / grip will be too loose on the green Y-axis rails? will this be an issue?

With slower speeds, the Y-axis show no problems.

I will try you suggestion and see what happens when the laserhead is operational on the green rails region.