TOPIC:

The Carvera Air have some elements where it could do better...

First, when milling, some chips tend to go under the machine, thru the slot left opened for the bed travel. That required to move the machine to clean under it... I spotted a chip bin on makerworld (makerworld.com/...a-chip-bin), and I printed it with the H2D. The top surface quality is really amazing (and totally overkill for the planned usage)... I placed it under the machine, and it will help for the cleaning as I won't have to move the machine anymore...



Second are the limited probing abilities. Now that I have a true 3 axis probe, I downloaded both the community firmware and the community controller (they are available here : github.com/Carvera-Community). They are forked from the Makera firmware and Carvera Controller (available here : github.com/MakeraInc) and the combination of the two allows the usage of a true 3 axis probe and there is quite a few ways to work out the definition of the origin of the work. While there is still a few bugs in the Community Controller and the Community Firmware, there is quite a good response on the Makera Discord. I discovered myself two bugs already while testing my probe, and they should be solved in the next release as the developper already fixed it...







That being said, while the home made 3D probe was an interesting project, I'm not sure it is quite reliable : there is bit of deviation along the time, perhaps as the printed parts are still unstabilized, which requires setting the runout by multiple measures before being able to set the work origin. The concept works, but it would require something more reliable for a real solution. Following this, I decided to move on and to buy a true 3D touch probe (cheapest prices are around 60€ and we need as well a 3 slot collet which works with the chosen probe), and I will just have to set the connection myself with a JST XH 2.54 4 port connector...

 

The weak point of the 3D printed Nylon 50T pulley for the Zerda was the thread to fix it to the shaft... It broke during the week-end in Montluçon. I tried to replace the setting screw with a bigger one after drilling a bit the the hole again, but it did not survive...



To be clear, I did not have much hope when changing the setting screws, and it was clear to me that I had to do something here... I thought about the CNC, but it was clear to me this would require to work with proper work origin, and that was one of the multiple use cases I had in mind for true 3 axis probing...

And yes, it is a different probe than the one we did with my brother... It's easily available on Aliexpress or Amazon (here in 4mm NO) and the run out is less than 0.005mm. This should be precise enough. The collet is a DGZ-60E TL60C 4mm and 3 slots again available on Aliexpress. It is super easy to change the collet and it allows to quickly prove a location using the Community firmware and community controller...
youtube.com/sho...b2SLDHLbPw 

I carved a slot in the Pulley 50T


Next, I'll work out an aluminium part to complement the pulley...

3 Axis probe is really helpfull for precise work requiring multiple faces operations... I started to drill and thread a 12mm rod, and then made a cut exactly where I needed it to be.



Then installed the part on the vice, and did the rest of the operations...




And the Zerda 2GT is operational again, with the weak point removed.

Working with the probe does appear to be a must... But it's not very user friendly to have to change the collet twice to use the probe at the start of each job... I had to change that.
Ordered a second probe, with the idea to make a mod...


The mod is simple : modify the shaft to reduce the diameter so it is working with the 1/8 inch collet I use with all the tool bits I have. But it requires a second probe to probe the shaft position precisely.



Once the work origin is defined next step is super simple : an outside countour of 3.175mm until the required depth...


And we have a new probe shaft, working in a 1/8 collet.

 

I really love the Carvera Air, and it is even more since I can probe anything...

On the Zerda 2GT, I replaced the cross member aluminium part by a 3D printed part... It works, but I would have prefered using an aluminium part... But I could not as I made myself a target not to have original parts... It is time to work this issue out...
I used a 100mm 6mm diameter rod in aluminium as stock. First identifying the center to be able to drill a small hole to work with the tail stock : a 3D printed part is ideal for this, then the hobby drill...


Next is the 4th axis work. I positioned the origin to avoid issue with the chuck and as well to be able to work out two cross member CT-58 in the stock...


Once that was done, I just drill a hole at the center of the part to be able to probe the center easily... That was done with a 3 axis job while the 4th axis was still present. I just did not touch the work origin while running thejob.



Then I positionned the part to be able to do the cuts, with some probing at the begining to set the work origin



Then last operation: drill and thread the sides. Probe, drill, thread repeat 4 times...



That took way more time than print a stl, in particular the 4th axis operation, but at the end, it is quite comforting to be able to do those parts... And yes, it would have been probably way quicker with a lathe, but I don't have a lathe, and now I start to think I need one

Modifying an existing part to add a single hole to be able to do symetric steering appeared to be super easy with the Carvera Air and 3-axis probe... As usual, it started by setting up the work origin (here the middle of the front inside edge) by combination of probing sequence. Then, I just had to set the hole in the right place.


Untll now, I would have used a jig to locate the hole and a drill... Here it is way more precise and it opens a huge number of possibilities, when it comes to modifying existing parts...

I got some TPU sample to try on the Carvera Air... Simple use case for it is a a flat bumper for the current 44B project I started recently...


I did a contour operation as a first test to verify that the settings were right... And then I cut the Bumper...


The result is not as clean as I thought for a single reason : the material is quite flexible and it tends to lift during the cut, which makes it difficult to have a perfect finish. This may be improved with some sacrificial layer of hard plastic or wood on top of it...

 

Tried something new for me with the Carvera Air : external threads... 



And it works... A bit of fine tuning on the diameter (2.98 instead of 3 for M3) to get it even smoother and it's perfect...

Now that I know how to do external threads, it is time to work somthing out... I have a fixation plate made already for the chuck, but for one of my project, it is bringing the stock a bit too high for me to be able to work the material out with some of tools I need. So it is time to work out another fixation plate, this time smaller.


The idea is to start with a stock with a thickness around 20mm, and it will require to work out 2 faces. There is a provision for a centering pin within the center of threaded part, on the inside face.

First face: surfacing, hole for centering pin, holes for fixation, contour (with a provision for tabs), chamfers

Second face: pocket around the threaded part, surfacing all around (it will be a big pocket), pockets around holes, surfacing, chamfers and contour (with a provision for tabs)

The critical elements about this work will be stock holding, and centering once the stock is turned upside down...