TOPIC:

Decided to pull the trigger on a Bambulab A1 Mini for very specific uses cases that I don't want to tackle on the X1C:

• Printing low shore TPU/TPE requires to change the extruder spring tension to work. This appear possible to do on the X1C by modding the printer head cover, but comes with additional issues (at least for me): I use my X1C so much that I don't want to have to think about what filament I used last time before pushing anothe filament in. Ultimately, convenience commands not to do this on the X1C, as changing the extruder tension would make the printer not working with anything than the filament you used last. In short I needed another printer for this. Further the A1 series have a tension screw easy to access on the side of the printer head
• Each time I'm going in vacation or in family, I regret not having a printer available. The A1 mini is small and easy to move, and that will be practical for rapide prototyping while travelling. I could even have it with me during RC event to print some stuff

I just ordered it while it is in stock, so it should arrive rapidly. I did not opt for the AMS lite as I don't see the point for my specific use cases...

Tamiya toolset box is quite fragile. I never took care of finding a solution... I did yesterday...

I designed a replacement part targeted for print without any need for supports, neither additional material...


I printed it in PETG with lighting infill set very low (3%) and with scarf seams (all countour, all default settings). 


There is room for improvement for the scarf seam, but both the PETG and picture does not help here... That said, it gives an homogeneous aspect all allong the face...


I'm happy with the result, and the STL is good... I may remove the scarf seam on the print profile I'll publish on makerworld.

It's on makerworld now... makerworld.com/...els/761187

I do have some aversion for unfinished/uncomplete product...
Few months ago, I've bought a Dremel Workstation 220... It's a drill press for Dremel, I bought it while it was on sale, in prevision for some of my projects. I opened it today, as I wanted to deal with some of my Zerda parts... And it was pretty disappointing : bolt to fix the column is too short (M10x16) to fix the column of the drill press, and the nut is moving while you tighten the bolt... 

Worse, it is bank holiday here, so it's difficult to get bolts just available easily as most local shops are closed. 
I finally found one M10x30 bolt in the single opened shop nearby. And I had time to think about solution on the way back from the shop. 

Once home, I designed a tool to put around the head of the bolt to tight it with my hand and one part to put the nut in place so it doesn't move anymore while you tighten it. Now my drill press should be usable, and i have shared the parts on Makerworld ( makerworld.com/...els/778028 ).

The Bambulab A1 mini is finally here... I had to go to the post office to get it, as no second attempt delivery...
Anyway, got it during my lunch break, and unboxed it while my wife was preparing the lunch... I was only switched on once my work day was over.

Once switched on, the calibration was started and done, then it requested lubrication of the Y axis (which I did).

I loaded the end of a Bambulab Basic PLA red to print a benchy. A red Speed Race Benchy. 20 minutes later, it was done. The White and Green were printed 18 months ago approximatively when the X1C arrived... 







The infill is set differently than on the X1C benchys, as well as the orientation of the bottom and top layers. Beside this, not much to say about this print : the quality is very similar to what was printed from the X1C and in terms of speed, it's not that different.
That being said, with an A1 mini, the tool head weight compared to the rest of the machine is a lot, and the A1 mini moves a lot during the print : this means I will have to find a way to secure the printer in place (I did not expect this).

One of the main purpose to add this printer to the crew is to print low shore TPU/TPE filament...
I had already some thoughts about the way I need to proceed...
TPU 60A will require to reduce friction so it means that the spool needs to be higher than the tool head, with the roll diameter being more or less tangent to the head vertical plan... I had a look at all the handles and spool holder proposed on Makerworld and none is actually doing what I want. The conclusion is that I will need to design a new one...
I unmount the Z axis cap, took measurements so I can start from there. And currently printing a test to check the cap is rightly modelised... Once this will be validated, it will be time to think handle and spool holder...

I got the Z-Axis cap right, so I started to design next part...

The handle will replace the Z-Axis cap and will support the spool holder. The plan is to use the provided spool holder (and a printed version of the slot). To reduce friction, I'll rely on an additional parts added to the spool holder with the idea to use some ball bearings... I'll design this part set next...


The slot will be installed with M3 nuts inserted thanks to a pause during the print. Easier for wide availability than anything else, as the chance anyone having M3 nuts available already is high.


I'm currently printing a draft handle to check everything, including the pause (I don't use this function usually, so I need to make sure it is made right).

While the handle was printing, I made my model for the spool holder.


It will rely on two 6807-RS ball bearings (35x47x7). It is composed of 5 parts. I'll put pictures once it is printed (I don't have the bearings yet, but will do us some prints in the meantime).

The handle was printed, but I did not have enough of filament, so I had to change filament at some point... 




The modified spool holder should allow to put the spool a bit higher, so it should be good enough for the TPU prints I intend to do (they won't be too high, so it should not be an issue : basically half of a tire ). The loading of filament is definitely easier this way than from the previous position, so that should work with the TPU filament. I should be able to do some test soon (as soon as the bearings arrive)

I've actually tried to print the bearing, but it did not work. In the first version, the rolls were not having enough surface to the bed to adhere well, and once one is gone, the print is going to be a nightmare. I stopped the print before it went nuts. 

I modified it to increase the surface in contact, and it did print, but once out of the bed, it was no longer a bearing . It's still good to try as it gives you some indications of what you can do for an inplace print...

That being said, the A1 mini worked the whole day with the handle and the spool support extension while I observed if it worked as expected -no ball bearings at this stage...



I revised a few things : the handle to give more height to the support, and to give a small angle to the support, so the roll stay in place (currently while printing, there is a plastic colar on the support extension to avoid the roll to move downward the support (which induce some torsion on the filament, surprisingly, by the way). I also modified the support extension to allow printing without supports and added a lock to the cap.

Now, beside the work on those parts, I noticed something : for small parts, the A1 mini is quicker than the X1C, not because of the speed, but because of the calibration process and the first layer inspection. I suspect this printer will be used more often than I envisioned when I clicked buy. I'm really happy with it. And to be clear, both printers worked simultaneaously at more than one occasion during this week-end...
 

One of my followers contacted me with a small project. The kind of things that would take me just few minutes... Siccom Magnum wheels. The locking mechanism is intersting, but the flask of the rim is quite fragile and becoming very difficult to find.




Indeed, it was not very long to model... And I printed one flask just to check it was correct... It was printed on the A1 mini, in the red PLA I use for prototyping, with tree supports and nothing else on the slicer settings... And the result below is not that bad, by the way...