Most of the FDM printers can get to similar resolution. Standard is 0.4mm nozzles and 0.2mm layers. 0.1mm Layer is fairly easy to go and dropping the nozzle size to 0.3 works and you can get 0.2 (tough to get it working well)
Here are some examples of the same components made in three different materials
- white: DirtyPCBs' SLA
- purple: Shapeways' strong and flexible nylon
- red: Prusa printer's PLA, 0.4mm nozzle, 0.15mm step, 100% infill
In the pictures below, the surface finish of the PLA and nylon is easy to see, but that of the SLA is so smooth the part appears to be out of focus!
The first component is a scope probe tip designed to (successfully) minimise the inductance of a ground lead. The dimensions and finish are non-critical, and the internal nibs are an interference fit over the probe.
The nylon is the best material since the outer walls deform when the probe is inserted, gripping well but allowing the probe tip to be easily removed without damage to the probe. The PLA works, but requires careful reaming out for it to be an interference fit, and its hardness an roughness damages the probe. The SLA is intermediate. Overall the PLA is sufficient to prove the concept, but it unsatisfactory otherwise.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=869084)
![](https://entertaininghacks.files.wordpress.com/2015/03/3dexterior.png)
The second component is a handle for a Tek P6013 HT probe. The key design feature is that the 2mm pitch thread which screws into the HT part of the probe.
The SLA variant works perfectly, inparticular the thread works surprisingly well. The PLA variant is a failure: the thread doesn't screw in, and the slicer automatically modified the shoulder's overhang.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=869088)
The final component is a collet for a Tek 24x5 squirrel cage cooling fan. The design points are the compression of the collet inside the fan, by being pulled to the left with a screw.
Lightly compressing the PLA variant with fingertips caused it to fracture along a layer boundary, so it is unlikely it could survive the tension exerted by the screw. That's not entirely surprising, PLA (and similar materials/depositions) was
never going to be a good material for this task. The SLA variant works well, and will probably be OK in the medium term: the SLA scope probe handle is fine after 4 years, and the collet won't get very warm.
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=869080)