RAMPS for BeagleBone February 05, 2014 09:43AM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone February 10, 2014 12:53AM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone February 10, 2014 07:12PM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone February 11, 2014 03:13AM |
Registered: 12 years ago Posts: 72 |
Re: RAMPS for BeagleBone February 11, 2014 07:44AM |
Registered: 11 years ago Posts: 62 |
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Kenzu
Uhh looks good, just what i need. But why only two low-current 12V FET outputs for fans/LEDs?
When can I order?
Re: RAMPS for BeagleBone February 11, 2014 08:14AM |
Registered: 12 years ago Posts: 72 |
Re: RAMPS for BeagleBone February 11, 2014 08:43AM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone February 15, 2014 03:46PM |
Registered: 11 years ago Posts: 5 |
Re: RAMPS for BeagleBone February 15, 2014 06:51PM |
Registered: 11 years ago Posts: 62 |
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Dougl
I would be interested in a kit if you do it even if beta./testing.
Re: RAMPS for BeagleBone February 15, 2014 06:55PM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone February 16, 2014 08:12PM |
Registered: 11 years ago Posts: 62 |
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cdsteinkuehler
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Dougl
I would be interested in a kit if you do it even if beta./testing.
I won't be selling kits, at least not for a while.
Re: RAMPS for BeagleBone February 20, 2014 11:41AM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone February 20, 2014 12:25PM |
Registered: 11 years ago Posts: 5 |
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cdsteinkuehler
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cdsteinkuehler
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Dougl
I would be interested in a kit if you do it even if beta./testing.
I won't be selling kits, at least not for a while.
Well, it turns out bobc over in the RAMPS-FD thread is using a PCB vendor with very good prices I had never heard of before. I decided to order 20 boards from them to try out the vendor, which means if they work out OK I'll have some blank boards for anyone seriously intersted.
Re: RAMPS for BeagleBone February 20, 2014 12:38PM |
Registered: 11 years ago Posts: 5 |
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cdsteinkuehler
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Dougl
I would be interested in a kit if you do it even if beta./testing.
I won't be selling kits, at least not for a while. I've only got three circuit boards coming back from OSH Park, at a cost of apx. $26 each. Add in the $70+ for a set of parts to put it together and any kit I sell soon will have to cost over $100. You might as well just buy an already put-together BeBoPr.
Once the design is proven, I'll see if I can get someone to build boards, or try to fund enough of a volume purchase the price can come down. This design should be able to sell for well under $50 if there's enough interest to get decent volume (as evidenced by the Geetech folks selling the V1 of the RAMPS-FD for $28). If not, expect to see prices similar to the early RAMPS boards (I bought my kit from Ultimaker for $85 back before the prices came down, and that's probably about what this board would sell for as a kit). Since the BOM will be very close to the RAMPS-FD and has many parts shared with the RAMPS, I'm hoping to be able to get someone who's already building the other RAMPS boards in volume to build some CRAMPS boards as well. That will require interest in the board, so if you want one, post here or otherwise "make some noise" in the usual RepRap hangouts.
Re: RAMPS for BeagleBone February 20, 2014 01:03PM |
Registered: 11 years ago Posts: 62 |
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Dougl
I was hoping you'd have had enough time to hear from people interested in PCB's so you could have ordered more than just 3 and also brought the price down.
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Dougl
BTW, the BeBoPr++ is just getting started and while I like the design and it's been proven, it's still an EU product and without giving away private info, it's still pretty costly to us US customers.
Re: RAMPS for BeagleBone February 20, 2014 07:03PM |
Registered: 13 years ago Posts: 10 |
Re: RAMPS for BeagleBone February 20, 2014 07:27PM |
Registered: 13 years ago Posts: 10 |
Re: RAMPS for BeagleBone February 20, 2014 08:51PM |
Registered: 11 years ago Posts: 62 |
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modmaker
I'm cranking op volume and the price has gone down from EUR 117 for the BeBoPr+ to EUR 84 already for a single BeBoPr++. When buying three boards the price is EUR 74 each. These boards include an accurate ADC to replace the crap version on the BeagleBone.
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modmaker
Your BOM does not include prices so it's hard to make a fair comparison and people here seem to focus on PCB cost only.
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modmaker
What complexity do you mean exactly? I see original BeBoPr features being integrated in the latest RAMPS designs (E.g. mergency stop and analog input protection), so RAMPS seems to be getting more complex with each new design.
Re: RAMPS for BeagleBone February 21, 2014 06:16AM |
Registered: 13 years ago Posts: 10 |
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cdsteinkuehler
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modmaker
I'm cranking op volume and the price has gone down from EUR 117 for the BeBoPr+ to EUR 84 already for a single BeBoPr++. When buying three boards the price is EUR 74 each. These boards include an accurate ADC to replace the crap version on the BeagleBone.
Great news, and those are great prices! Keep us all updated on the options for purchase, and I'll get my blog cape page updated if you send me details. Do you have any plans for a US distributor?
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cdsteinkuehler
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modmaker
Your BOM does not include prices so it's hard to make a fair comparison and people here seem to focus on PCB cost only.
My cost for one board right now is about $100 US, but that's parts only, qty 1, buying parts for one board from DigiKey ($70) with PCB from OSH Park ($26 ea), and probalby another $5-$15 in parts that I got sampled or have on-hand (the stack-through connectors and a couple TI parts). As I mentioned to someone else, at this point buying a pre-built BeBoPr is still the best way to go (and could easily continue to be). If I was selling boards (and I don't plan to), I likely wouldn't be able to match your 117 EU for assembled units, much less the 84 EU price of the ++, certainly not without getting into buying lots for 50-100 boards at a time...and I don't want to get into the board business. I honestly did this design as much to test out KiCAD (it's workable, but _painful_ to use for production designs in it's current state) and run some larger boards through OSH Park and some off-shore vendors as anything else.
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modmaker
What complexity do you mean exactly? I see original BeBoPr features being integrated in the latest RAMPS designs (E.g. mergency stop and analog input protection), so RAMPS seems to be getting more complex with each new design.
Yes, the CRAMPS (and the RAMPS-FD it's based on) are more compelx than the inital RAMPS board (which was mostly just a PCB with various connectors), but it is still simpler in design than the BeBoPr or Replicape. Specifically, I'm referring to things like:
5V power: This is provided by the BeBoPr/Replicape, but the CRAMPS requires you provide 5V to the BeagleBone or populate a header with an optional 5V regulator module.
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cdsteinkuehler
FET Drive: The CRAMPS/RAMPS-FD uses the same logic-level FETs with 5V drive as used on the RAMPS. I've never much cared for this solution and it means more expensive FETs and larger packages to dissipate the resulting heat from not using a 10-12V gate drive. But the RAMPS-FD folks didn't like my "poor-man's" FET drive suggestions, and I'm sticking with the 74ACT drivers they settled on. They are readily available and inexpensive, the only drawback is the 5V gate drive. :-/
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cdsteinkuehler
I/O Protection: The CRAMPS does what I would classify as minimal protection. It should be possible to hook 5V signals up to some pins, but overal it will be much easier to fry your BeagleBone using a CRAMPS board than a BeBoPr.
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cdsteinkuehler
ADC: As you mentioned, the on-chip ADC on the BeagleBone "lacks performance"The CRAMPS design uses the on-chip ADC (and inherits all the noise and other problems that brings with it), and has what I would define as minimal input protection. I'd feel much better with op-amps in the circuit, but those cost money and aren't on the RAMPS-FD BOM (another goal is to try and get some RAMPS/RAMPS-FD vendors to build the CRAMPS too, so having a very similar parts BOM is important...I don't want to get in the building boards business).
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cdsteinkuehler
Overall, I see room for a spectrum of products. There are several low-cost CNC capes available, I did the CRAMPS board because I'm hoping it can fill this segment for the 3D printer folks. The next step up would be a board like the BeBoPr++ or Replicape, followed by something like an FPGA daughtercard (none are currently available, but a few designs are in the works). Note that my perspective is focused on using LinuxCNC as the control software. I know you have your software, and Elias has something he's using with the Replicape (I honestly have yet to test out either...I should do that sometime!). Choice of software can dramtically affect the decision of hardware to buy...for instance the BeBoPr is the *ONLY* board currently supported by LinuxCNC. Even my CRAMPS design doesn't have any working example configurations yet, and it will probably be some time until the Replicape is supported, since it requires use of various hardware interfaces (I2C and SPI controllers) I haven't written LinuxCNC HAL drivers for yet.
Re: RAMPS for BeagleBone February 21, 2014 10:51PM |
Registered: 11 years ago Posts: 5 |
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modmaker
Hmm, I'm curious to hear what you have to say about EU products... Please share your thoughts with us.
-- Bas
Re: RAMPS for BeagleBone February 24, 2014 12:18PM |
Registered: 13 years ago Posts: 10 |
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Dougl
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modmaker
Hmm, I'm curious to hear what you have to say about EU products... Please share your thoughts with us.
-- Bas
oops, I didn't mean it the way it might have been taken. I know Charles is also in the USA so the comment about it being an "EU product" was 100% related to cost and how long it would take to get production up for USA purchasers. I recall even sympathizing with you all over there when I posted, having read many times about this or that USA product being tough and/or expensive to get over the pond. I'm sorry that I may have stirred your emotions a bit with the previous statement.
Doug
Re: RAMPS for BeagleBone February 24, 2014 05:45PM |
Registered: 14 years ago Posts: 1,352 |
Re: RAMPS for BeagleBone February 25, 2014 06:02AM |
Registered: 13 years ago Posts: 10 |
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NoobMan
US price probably does not include vat because they dont have that. EU price probably includes it, most probably all components have that included in purchase price. So the eu price is comparable if you keep track of vat. If one would want to import large quantities or merchandise from us to eu, would have to pay vat at customs, the vat in the country where the import is made. Sort of speaking, can not avoid eu vat indefinatelly nor completely.
Re: RAMPS for BeagleBone February 25, 2014 06:52AM |
Registered: 14 years ago Posts: 1,352 |
Re: RAMPS for BeagleBone February 27, 2014 09:35AM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone March 01, 2014 10:19PM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone March 25, 2014 10:57PM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone May 07, 2014 07:48AM |
Registered: 11 years ago Posts: 62 |
Re: RAMPS for BeagleBone July 21, 2014 10:24PM |
Registered: 10 years ago Posts: 1 |
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cdsteinkuehler
The only thing not really working as expected is the thermistor inputs. The signal levels are so low at room temperature with a 1.8V ADC range that the leakage from the protection diodes is causing measurement offsets. I am considering simply removing the protection diodes from the next version (I have already removed them from my prototype), as I'm not sure they really help all that much. The right way to protect the inptus is with a high input impedence insturmentation amplifier, but that costs money and adds complexity. The design still has a 4.7K series resistor to help protect the analog inputs, which probably puts the BeagleBone about even with the Arduino Mega used with the original RAMPS (which had absolutely *NO* analog input protection at all, but the AVR is likely a bit more robust than the AM3358 on the 'Bone).
If you have any strong opinions about keeping or removing the analog input protection, let me know.
Re: RAMPS for BeagleBone July 22, 2014 05:20PM |
Registered: 11 years ago Posts: 62 |
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kroylar
What have you done with this in the newer versions of the board? Particularly, I see that a fully assembled v2.2 board is available from pico-systems. What is the state of the thermistor readings at room temperature with this version?