Topics created by Falkia

@apak Please check this Thingiverse.

@falkia I have tried E3D's slimline motor (mt-1701hsm140ae) and compact but powerful motor (mt-1703hsm168RE) on my BMG in a flying extruder. I definitely hit limitations and have to compensate with flow rate with the slimline as I increase print speeds. When I'm doing flexible filaments it's not an issue since the print speed needs to be lower anyways. The other part is that the motor runs hotter than you'd expect and may run into issues there such as using PLA for your flying extruder mount. It is within spec and not necessarily bad but definitely outside of the comfort zone of many because it's smaller and you don't have extra torque to trade off in lowering your motor current to reduce the motor heat to keep it cooler than the hotbed.

@falkia No probs, obviously change the pin name to that of the Duet 2 should have said that :).

@phaedrux That's the one I used but it is limited to 16 points.
According to the wiki it's possible to have 32 point. My delta is quite large so I thought that running the calibration with more points should be better but maybe 16 is enough? However it's not a big deal to add them manually.

I can confirm that this is now fixed in 3.4-b7. Thanks @dc42

@fcwilt no but that was a good idea.
Thanks

@chrishamm Yes the new config tool works (version 3.3.9).
Thanks
Fredrik

@dc42 said in Beams as stiff as steel:

Footnote for pedants: it is sometimes said that person is "under strain" but this is technically incorrect. A person can be under stress or exhibiting strain.

In the good old days (before Amazon) I once tried to get a bookshop to order 'Roarks Formulas for Stress and Strain' (which is a standard structural engineering textbook) and the assistant outright refused to search for it under engineering, insisting on looking in psychology and psychiatry and related fields. They couldn't find it there in the catalogue so maintained they couldn't order it. I gave up, and found it on the shelf in a better bookshop in a more academic city.

Thanks for all inputs. I ordered These. Supply voltage 3-6V and with LM393. Not the cheapest ones but located in Europe (shipping from China takes forever nowadays). I hope they will work. 🤔

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Hi,
The progress for my project is slow but during this week I made some V-Slot gantry plates and belt clamps that fits the plate.
Edit: the clamp with teeth is bought.

Also adding some photos of the extrusion corners that my son helped me to fabricate and a photo of the frame assembled. The corners fits the extrusions very well with slide fit (near press fit). I also fabricated some longer M6 T-nuts. The frame is very rigid.

Why I choose to fabricate in aluminum with CNC machines? I want to learn Fusion 360 for design and manufacture (post processing CNC program) and I have access to machines.

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@dc42 thanks. Now the design will continue.

There are several consideratoins:

As @Veti says, you should make sure that the rest of your mechanics is compatible with whatever pulley size you choose.

Assuming GT2 belts, at x16 microstepping the steps/mm will be 160 using 20 tooth pulleys, or 200 using 16-tooth pulleys. So slightly better resolution per microstep using 16-tooth pulleys (5um) vs 20 tooth pulleys (6.25um). Also, 5um is easier to work with than 6.25um when measuring Z probe trigger heights.

The full step resolution will be 100um using 20 tooth pulleys, or 80um for 16-tooth pulleys. Some users prefer to use a layer height that is a whole number of full steps; in which case 100um is easier to work with than 80um.

20-tooth will allow a slightly higher speed than 16-tooth before you run out of either VIN voltage to counter the motor back emf, or step generation rate

If using 1.8deg motors then I think it's worth using 16-tooth pulleys to get better resolution. With 0.9deg motors, I don't think it makes much difference. I started off using 20-tooth pulleys and 1.8deg motors, then changed to 16 tooth pulleys for better resolution. But then I changed to 0.9deg motors. I still use 0.2mm layer height even though it is not a whole number of full steps.

The only one of these I have on a heated bed at the moment is labeled "40A", which probably means it is 16.

The bed is about 1400W, on 110/120V (US standard). So about 12A. Seems OK. Also, it has been in operative use for some months, and I've applied the highly scientific "put your hand on the case" temperature reading. It is never even warm, in an average room (about 21 to 22C).

@Falkia there are a couple of reasons I can see to use scara, both relatively niche for 3d printing. Voth are related to the fact they have a small base and print outside of that base area. A scara can be easily transported, clamped to a surface and then print on that. Also they can, in theroy print over a very large area compared to the size of the printer.

In normal 3d printing applications though the lack of rigidity (meaning sag and artefacts in the printing) make them a poor choice.