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Discuss any sort of mechanical stuff here: positioning systems, gears, extruding methods, etc.
Re: RAMPS for Due! - 11 years ago
Quotecdsteinkuehler ...and one more: In trying to calculate a new operating point for the TLV431 used to clamp the ADC voltage (the BeagleBone has 1.8V Analog inputs), I thought I'd check the existing operating point. It doesn't look like ANY current is flowing through the exsiting regulator. If the schematic indicated values are correct (R1002=10K, R1003=1.5K, R1004=1K), that's 12500 ohms fby bobc - Controllers
Re: RAMPS for Due! - 11 years ago
Quotecdsteinkuehler Another question: I notice the LEDs for the high-current MOSFETS are driven by +5V instead of +V_POWER, and I'm wondering why. Typcical LEDs have very low reverse voltage ratings (it's 5V for the OSRAM LH R974-LP-1 pulled up by the DigiKey part number in the BOM), and typically don't include specifications for zener or avalanch mode. If +V_POWER is 24V, that puts 19V of revby bobc - Controllers
Re: New light extruder concept out of bolt - 11 years ago
This is a great! With counter rotating drive force, I can't see twisting is an issue. It would be interesting to try running with just one drive nut even.by bobc - Mechanics
Re: is posible stepper motor in continuos rotation? - 11 years ago
Not sure what you are asking for. In a lathe the spindle turns continuously at a set speed, so it is more like a tool head than an independent axis. A 3 or 4 axis CNC mill with a rotational axis is similar in that it has a chuck to hold the workpiece, but the chuck is an independent axis and it's position is controlled, it can rotate freely in either direction but does not rotate at high speedby bobc - Stepper Motors, Servo Motors, DC Motors
Re: Stepper Motor Connectors - 11 years ago
You already found the answer, but those JST connectors are widely used in Japan, and perhaps less common in Western designs. More info here If you are using crimp terminals, then you need . Alternatively there is an IDC connector, , you can probably push the wires in with a screwdriver.by bobc - Stepper Motors, Servo Motors, DC Motors
Re: Newbie with ambitious build - 11 years ago
Unfortunately, although the mechanics of CNC and 3D printing seem quite similar, in practice if you follow the requirements to the logical end, the 3D printer ends up look quite different to the CNC machine. I think it is a rabbit hole a lot of people try to go down, but in the end not many are successful. If you have high lead screws and good motors, then the speed issue can be addressed, butby bobc - Extruded Aluminum Frames
Re: New makerbots? 5th gen? - 11 years ago
So I am guessing that they are not Open Source designs and Makerbot are quietly leaving that world behind them. Their market is no longer makers but the "prosumer" who doesn't care one way or the other, so not a problem for Makerbot. OSHW was clearly a stepping stone on the way to personal riches. There does seem to be a limit on how big an OSHW can become before Big Money comes in the front dooby bobc - Reprappers
Re: Big printer build, 400-700-600 - 11 years ago
RAMPS works quite well with external drivers, although some config may be required. Quite a few people are using some variant of the Toshiba driver (TB6560 etc) which can handle 3A and more for about $10 per axis. I am looking at how to support this config with a interface header board on the RAMPS.by bobc - Reprappers
Re: USB Comms issues - 11 years ago
I think it's a classic case of interference on the USB causes it to hang up. Do you get the Windows USB sounds? There are a few things you can try, better quality USB cable, or even just a different cable, a shorter cable, use USB hub, add ferrites to the USB cable. it could also be a fault on the RAMPS or just excessive comms errors. Printing from SD is certainly worth a try.by bobc - Reprappers
Re: RAMPS for Due! - 11 years ago
Initially I tried to keep things similar to RAMPS, then realized they were too many differences (e.g. 3.3V vs 5V, SPI on different pins, etc) so just assigned unused IO to connectors as convenient. I then realized I could get compatibility with SDRAMPS (SD card module) if nothing else, so Aux3 can be used with SDRAMPS. Maybe with BBB an SD card extension is less useful. The rest are pretty muchby bobc - Controllers
Re: wiring xbox PSU+relay+RAMPS 1.4 - 11 years ago
Wiring looks ok, but make sure to double up the wiring from the PSU to the relay (yellow to 30).by bobc - RAMPS Electronics
Re: Newbie with ambitious build - 11 years ago
The heatbed is usually run at 95-100 deg C for ABS, around 60 for PLA. Be aware that Rev 1A of RAMPS-FD has some undesirable issues, but is still usable (and surprisingly cheap). Rev 2a is nearing finalisation, but I can't guarantee it will go into production, although hopefully some Chinese manufacturer will pick it up.by bobc - Extruded Aluminum Frames
Re: assist bowden with second small stepper - 11 years ago
I had the same idea, but haven't got round to trying it. Seems like a worthwhile idea on paper. It's quite simple, and I don't see an issue with synchronization.by bobc - Mechanics
Re: Stratasys sues Afinia - 11 years ago
The USA has pioneered capitalism, free trade, free market, hire and fire, "intellectual property rights", corporate greed etc, even to the point of being a national ideology. That was fine when USA was great and selling to the world, dollars pouring in to the US, and making others countries beholden to the US. But now when it comes to the same philosophy biting the USA in the butt... they thinkby bobc - General
Re: RAMPS support needed.. - 11 years ago
I think for the control signals you have step,dir,enable and common, so 4 there. You could wire enable permanently on. Separately you need power for the motors, so maybe another two wires there. You'll need to make sure your power supplies can share a common ground, or derive 12V from the PSU for the motors. Looking closer at the SCL interface, it appears to be RS232 at 9600 baud on the model yoby bobc - RAMPS Electronics
Re: Anyone already doing an open source 5-axis cnc? - 11 years ago
I think it would be an interesting project, although no way I could build something as big as the Calvino design. Mike's kickstarter was perhaps an exercise in how not to go Open Source, I would have contributed a few dollars for no reward, but wouldn't pay $700 for a design I have no intention to actually build. I think the way to Open Source such a large build is publish from day 1 and hope toby bobc - CNC Routers, Mills, and Hybrid RepRapping
Re: RAMPS support needed.. - 11 years ago
All Reprap boards, RAMPS included, are designed for STEP/DIR operation, so that should work out of the box. SCL on the hand, will require significant development work, both hardware and software. I would go with the Step/Dir interface.by bobc - RAMPS Electronics
Re: Newbie with ambitious build - 11 years ago
1. Yes, I think they should work ok. You would just step, dir and enable to the RAMPS. 2. A heated bed is not essential for PLA, although for large parts it can help prevent warping. For ABS it is pretty much a must. 3. 1.75 mm filament allows smaller lighter extruder, but if you are using lead screw you may not be able to exploit that. The hotends are usually compatible between extruders, so yby bobc - Extruded Aluminum Frames
Re: printed object is reversed? - 11 years ago
That means the Y axis is reversed then.by bobc - General
Re: Cooling Fan: no voltage - 11 years ago
Ok, for M106/107 you need to set FAN_PIN to 9, and have "#define FEATURE_FAN_CONTROL true" FAN_BOARD_PIN should be -1. -1 is used to indicate the pin/feature is not to be used, since pin numbers are >=0. I think FAN_BOARD_PIN is a fan which is on whenever the printer is "active", possibly turned off after inactivity delay. Repetier has a lot of features, not obvious how to configure it allby bobc - RAMPS Electronics
Re: Predatory Profit Margins - 11 years ago
Wow, you still got a grudge against Prusa. You should just let it go man! Of course, there is no such thing as "true cost", it is all relative. Supply and demand. I disagree with the idea of tipping as a % of sales in Open Source as a customary practice. It is too close to paying a royalty for the use of IP, which is the exact opposite intention of Open Source. If you have some developers beingby bobc - General
Re: Cooling Fan: no voltage - 11 years ago
Have you tried plugging a fan in? You will get no voltage across the terminals because it is a low side mosfet. D9 is the pin number, i.e. Arduino pin 9. ISTR having trouble with the SD detect as well, but didn't try to figure it out. ETA: hmm not sure about that...by bobc - RAMPS Electronics
Re: Megatronics v2 problems - 11 years ago
The mosfet shouldn't get hot when the heatbed is off, since there is no current flowing, so that is a puzzle. It's possible to overheat the mosfet if you have PWM turned on for the heatbed, check you have it set to bang-bang control. Some cheap suppliers substitute a mosfet with non-logic level input, which don't switch on enough at 5V. They also substitute lower spec parts for the screw termiby bobc - Controllers
Re: Predatory Profit Margins - 11 years ago
QuoteHazer After reading this, let me give a different perspective. Just like everyone else, when I first read the initial post I was thinking "what is he getting at?". I thought he was talking about printers in general. Of which, IMHO, they are hardly 500% markup from material. Anyway, after seeing his Ebay stuff I can get where he is coming from. He sells a slightly different J-head for $25, oby bobc - General
Re: Predatory Profit Margins - 11 years ago
Wow, good job I had my speakers turned up to 11, otherwise I would not have been able to fully appreciate your "Emission Statement" Anyway, ohioplastics acts like a troll but I am not sure he intends to. I think he is a bit more like a bull in the china shop, it's the way he comes across. I am fully behind Open Source, all I ask is that people don't try to take ideas out of the public domainby bobc - General
Re: Introducing the ramps 10 - "Ramps10" an open source multi-configurable stepper controller shield based on the Ramps 1.4 design. - 11 years ago
I have made a few more changes. Added fuses for each section, extending the board size to 150mm to accommodate this. The fuses add only $1-3 to the cost. The increased area allows a much cleaner layout of the power zones. I've also spaced all the connectors to allow latching connectors (e.g. KK100), although Molex 0.1" type can still be used if preferred. I've a nagging feeling the power connectby bobc - Developers
Re: DIY 12V supply for the budget-conscious - 11 years ago
Lots of people in RepRap community use the Mk2 heatbed, most of them use 12V PSU, and many of them print ABS. There is lots of experience with this setup. Experience shows it works fine, but you need a *good* quality PSU, and the el cheapo ATX PSUs are generally not good enough. Their ability to deliver enough current on the 12V is too far below spec. I don't really know why RepRapPro would shiby bobc - Ormerod
Re: DIY 12V supply for the budget-conscious - 11 years ago
The Ormerod appears to use a standard (Mk2?) PCB heatbed, it should take less than 10 minutes to reach 100 deg. If it doesn't, then there is something wrong with it, or the wiring. There are duff heatbeds around with resistance too high because they were not made properly, the resistance is quite critical. It should be between 1 to 1.2 ohms. I would fix the heatbed before considering DIY power sby bobc - Ormerod
Re: Pololu DRV8824 behavior vs 8825 -- what's going on here? - 11 years ago
Interesting, I also had problems with Repetier on Allegro drivers on some moves. I suspect it is a problem with Repetier, since I don't have problems with other firmware. The fact that you say it works on some drivers but not others suggests it may be a problem with pulse timing, probably the width of the Step pulse, and Repetier generates pulses that are too short. According to the datasheets,by bobc - Controllers
Re: Arduino's Max Stepper Freq? - 11 years ago
It really depends on how the firmware is written, but I've seen figures of 10-30kHz claimed. Is there a background to the question, or are you just interested?by bobc - Controllers