He's using the V6 lite which should work on bowden
@ultiarjan this might (or maybe not) be interesting for you? No idea..
I just downloaded the new cura... New 'legacy'? wherever the name, the new, old cura. From Lulzbot 17.10 (they ofc have keep pushing the number like anyone would do instead of going for date)
What's new? NO IDEA. But, on dual, this it's interesting (since they are programming more where it was left)
Also yesterday tested the new beta cura, the UI it's a mess...
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foehnsturm 970
That's a badass big blower!
Are you going to assign it to an axis to follow the head movements? Looking good!
foehnsturm 970
it's only a workaround. I want to use a pwm-able crossflow fan. But it's 130 bucks and earliest possible delivery mid November.
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Have you tried running the non-PWM crossflow fan on a PWM control + RC-filter? With the right components you can make a pretty good adjustable DC source with only two components (an R and a C)
foehnsturm 970
Well electrical engineering was my minor subject at the university. But I hardly remember a thing ... The fan I'm using on the UMO has a start voltage of 8V (max 12V). Does this mean anything regarding the controllability?
Yes, it means the fan should start turning when you power it with 8V DC.
BUT, if you have an adjustable DC voltage (for example a laboratory power supply), then you can "kick-start" the fan by supplying 12V DC for a few seconds. Then, you can lower the voltage which will also lower the fan's rpm.
At some point it will obviously stop. But that should be more like 5V DC, maybe even less.
The fan needs a certain amount of power in order to overcome the rotor inertia. Once the rotor is moving, you can lower the power.
Now, an adjustable DC voltage is not the simplest thing to achieve.
Mathematically, a PWM'd voltage is the same as adjusting a DC voltage.
12V DC, with 50% PWM, is effectively (mathematically) 6V DC. But in reality the voltage switches between 12V and 0V rapidly. Many fans don't like that and may be damaged when you apply a PWM'd voltage to them.
But there is a way to "actually" convert a PWM'd voltage into an adjusted DC voltage: By adding a low-pass RC-filter that flattens the PWM signal away, leaving a "more or less" DC voltage. There will be some ripple left in the voltage, but that won't matter to the fan.
This is the simple part. Now you want to know the correct values for the resistor and capacitor. I have to admit I've never actually done this before, and there are quite a few things to consider even for something as simple as an RC filter.
I can try putting together a little experiment at lunchtime. I'm not really the type to try and find a mathematical solution. I'd rather just put it together and see what happens. Then (maybe) derive a formula from that...
foehnsturm 970
Thanks a lot. Would be definitely worth a try. I just connected the fan (conrad.de, brand x-fan) to an adjustable power supply. In fact, it runs from 12V down to 3V and even starts with a voltage as low as that.
Tried conducting that experiment. Sadly, I couldn't get it to work because I don't have a suitable PWM generator. PicoScopes are really useless for these kinds of things :(
I'll need a battery powered PWM generator. Makes taking measurements and experiment set-up a lot easier...
I'm ordering one from ELV, but it will take a few days for it to be delivered.
foehnsturm 970
Nice drive wheel
Maybe you could save some more weight by cutting out spokes?
What drivers and current did you use?
You can probably get it to run cooler with a TMC2100 stepper driver. At least if you use it in a dual toolhead scenario where there are large portions of "waiting time" - the TMC2100 can automatically lower the motor current when it is not in use.
Maybe a thin aluminum sheet can act as a passive heatsink?
Edited by Guestfoehnsturm 970
better now
You can get some Velcro braided sleeve like the one found Here to tidy up your cables. But it also gives you the flexibility to access them at any time.
foehnsturm 970
BTW, for anyone looking for gear wheels with less than 18 teeth (module 0.5) with a 5 mm bore (which I found quite hard to source): link
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BTW, for anyone looking for gear wheels with less than 18 teeth (module 0.5) with a 5 mm bore (which I found quite hard to source): link
Interesting! Misumi only goes down to 15 teeth minimum. Makes quite the difference for the large gear when you need 1:6 transmission...
The large gear looks pretty heavy though. Why didn't they include spokes in a steel gear o.O
Do these gears match with any other module 0.5 gears, e.g. the ones from Misumi? (GEABM0.5-50-3-B-5)
/edit:
Oh, wait. 10 teeth only has a 3mm bore. :(
Well, 13 (smallest with 5mm bore) is still better than 15. Will try one
Edited by Guestfoehnsturm 970
Do these gears match with any other module 0.5 gears, e.g. the ones from Misumi? (GEABM0.5-50-3-B-5)
I strongly suspect that.
It's a 13:50 reduction now (1:4.6)
13:50 is ~ 1:3.85, not 1:4.6? Just to make sure I'm not messing up my calculations
Ordered one of these 13 tooth gears. Misumi will have to wait a bit, though. I don't want to bother them with a 1-item-order..
/edit:
Gotta love Misumi
You can directly download STL files of their parts from them. Will make a quick mockup gear set now
Edited by Guest- 1
foehnsturm 970
made a mistake it's actually 13:60:O
Föhnsturm, if you want to "pwm" the fan, here is my advise:
Just buy a pack of 10 Capacitors, each 10µF and start with one parallel to the fan. If it doesn't start at your desired Voltage, add another Cap parallel again. Rince and repeat till you are happy ;)Cost: less then 5€ with shipping, e.g. something like that: http://goo.gl/KrbvQ4 (ebay.de as I assume you are german as I am).
I also don't know if your firmware is capable of PDM instead of PWM, PDM is a better signal for cleaning voltage out with capacitors and is just superior than PWM.
Also, I can recommend you this fan: Lüfter, Titan, 50x50x15mm, TFD-B5015M12B, radial, kugelgelagert http://r.ebay.com/EAHXXU
This fan works out of the box and down to 4V in my current printer.
Furthermore, I am, as always, impressed by your designs! Keep up the work!
Edited by Guest
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jonnybischof 60
True, true...
I've been working on a new printer for.. 2 years? 3 years? I don't even know anymore...
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macua85 52
Im also going to keep an eye on this, once again foehnsturm is leading the innovations! I could event go back to e3d perhaps (seems direct drive 3mm works way better than Bowden 3mm).
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