darmach's blog

tech junkie


One of the last remaining parts was Y carriage assembly. I decided to cut the frame from 3-4 mm thick aluminum, should be light enough not to make the difference on carriage weight, while being quite stiff. This is what I came up with:

Aluminum Y carriage design

Aluminum Y carriage design

As for cutting, I visited a company operating a waterjet cnc cutter – amazing stuff! Take a peek how it went :)

That was a long time without any signs of life!

Last batch of the printed parts

I bet y’all thought I dropped the project! But no. An unfortunate turn of events didn’t allow me to work on the printer since last update – but not anymore.

Few last parts arrived some time ago, they were X axis carriage, and all printed elements for Y axis: smooth rod mounts, stepper and pulley holders.

And here they are!

I will add all of the stl files to my thingiverse page tomorrow for download.

Another few pieces of the puzzle

All the pieces

Another few pieces of the puzzle arrived, managed to assemble them together and get a little glimpse of the whole picture .) As previously, I’m amazed at the quality of the laser prints – SLS is an amazing piece of technology.

I have already added some of them on my Thingiverse page to download, rest will be added later today.

And here they are:


both X axis ends, one with stepper motor mount.


Z axis module, lower stepper mount, upper smooth rod mount, and an X-end in the middle

X-axis assemble

X axis assembled with short smooth rod – just for testing purpose

All the pieces

All the toys

Tiny, tiny, tiny pulley

623zz pulley for GT2 timing belt

Some time ago I posted a render of the 623zz pulley – a tiny pulley to guide GT2 timing belt. I was aware of the dimensions of the part (well, I designed it to have certain dimensions to fit around 623zz bearing, right?) and this is how render looked:

Pulley for 623zz bearingAnyway, even with me knowing how small the part was – it’s amazing how tiny it is when I received it printed. I hope it will work well, we’ll see… Take a look at it in real world:

623zz pulley for GT2 timing belt

623zz pulley for GT2 timing belt

And last picture – standing on a small coin for comparison:

623zz GT2 timing belt pullem on a coin

Told you its tiny!

Not so ‘smooth rod’ ?

I received yesterday smooth rod sample from one of the local suppliers.  I’m pretty sure something is wrong, but I have no idea if with the rod, or the bearings. Take a look how it behaves:

I must admit I expected it to slide smoothly along the rod, and even when I tilt it vertically – the bearing just sits there, on the top, until I pat it! This doesn’t seem all right… Also a certain stuttering can be felt when you try to slide it.

Funny thing – I cooled the rod to below 0 degrees centigrade (just put it in the freezer actually), and suddenly it slides perfectly! The question stands: is the rod too wide, or the bearing too tight…….?

New thingie – 623zz Pulley!

Pulley for 623zz bearing

I’ve been looking at different printers, and noticed how many of them uses 608zz ball bearings as toothed belt pulleys, along with GT2 16 teeth pulley on the other side. Say I’m crazy, but I hate the way it …looks! GT2 pulley is less than 15 mm in diameter, while 608zz is 22 – which makes belt running non parallel to itself and smooth rods.

This was the reason I decided to do something about it – and designed a pulley to be mounted on a 623zz ball bearing (such a tiny, tiny one!).

So there it is! What do you think? I wonder if 623zz will live long enough .)

Yeey, made new thingies!

Another render of reprap parts I made.

After a few days I can get back to you with some updates. I managed to create two parts from scratch – but they are still compatible with Nutz95 design. I have uploaded them to Thingiverse here. What feature I’m most proud of is designing part mount around aluminium extrusions. I have added 8 mm rectangular pins, fitting 30x30x8 mm aluminium extrusions row holes (which are actually 8,2 wide)

Click ‘Read more’ to see 3D model.

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