The 1N400X diodes are just different max reverse voltages. From memory 1N4001 is the lowest at 50V and is quite adequate for 12V system so any in the series will do. I think you got the 78L05 the wrong way round. 7805 is bigger than 78L05. It will work but it won't fit the PCB. Yes the H21L01 does seem to be obsolete, I can't even find a datasheet.by nophead - Controllers
Eric, I didn't use a 5mm section from the main shaft, I substituted 5mm cut from a bolt so I had no trouble soldering that end. Are you saying that you have your main shaft 5mm longer, hence the hole 5mm deeper? I did think of reducing the main shaft by 5mm and screwing it into a brass rod with a hole to take the cable in the other end. That would solder nicely and I could secure it with a loby nophead - Mechanics
Jonathon, Kai has got the loop back comms test working with a link between the PIC pins. That must mean the link from the PC to powercomms board is ok. Also the links from it to the UCB must have continuity. I think the only faulty cabling possibility left is TX and RX links swapped at the UCB which would still pass loopback but Kai has double checked this. It might be worth just swapping themby nophead - RepRap Host
Well I think all the PIC needs to respond is power. It should have 5V between pins 14 and 5.by nophead - RepRap Host
I know it's only a little thing but it can't give a good impression to the world, putting out an RSS feed with a bum URL in it for months.by nophead - Reprappers
Well I made it without and I now think it it required to allow you to insert a new piece of filament when the old one runs out. Perhaps a shallower incline would be better for this.by nophead - Reprappers
I found that solder doesn't stick to stainless steel properly. My joint failed after a few minutes use. I re-soldered it but I don't have a lot of confidence. Eric has shown that JB Weld does not work so if it fails again I will drill a small hole and put a pin through it I think.by nophead - Mechanics
If JBWeld is supposed to be a strong as steel how come I can scrape it off with my fingernail after 24 hours?by nophead - Mechanics
You could still have your TX and RX crossed and get a successful loop back test. Are you sure TX on the comms board goes to RX on the UCB and visa versa?by nophead - RepRap Host
Surely, until the RepRap Darwin is able to make its own parts, it is not worth building since you won't be able to make much else that is useful. After all, its parts are not particularly complicated objects. A soon as it can, parts will flood out exponentially. Why try to jump the gun by buying an expensive machine?by nophead - General
mimarob, A few tips: 2W is about the most you can dissipate with a TO220 with no heatsink. With a modern MOSFET you should be able to get a low enough RDSon to not need a heatsink at all, even at several amps. Looks like you are not giving enough gate drive to turn it on fully. Sometimes a MOSFET will oscillate at very high frequencies causing it to get very hot. The easiest way to fix it is tby nophead - Mechanics
It looks compatible electrically but physically it is a lot smaller and probably doesn't have enough torque unless you want to build a scaled down version of the machine.by nophead - Mechanics
Of course getting a successful lookback, even from the PIC pins, does not rule out the cables being crossed over. I.e. RX and TX swapped.by nophead - RepRap Host
I too have been underwhelmed by the strength of JB weld. I read that it is good for attaching heatsinks to CPUs, a thin layer is apparently a good thermal conductor. The article said the downside was you would never get it off again. So I used it to fasten 1W aluminium backed LEDs to copper PCB material. One LED failed so I thought I was going to have a problem removing it, but it came off easilby nophead - Mechanics
From my experience cutting the bearings I would say a standard hacksaw wastes a shade more than 1mm, particulary if you clean up the cut edge, and a junior hacksaw a shade less than 1mm.by nophead - Reprappers
You need to change the serial port from /dev/ttys0 to COM1 on Windows.by nophead - Controllers
It is M5 threaded stainless steel. Here in the UK metric is standard! Yes I turned the lands and bored the hole using a watchmaker's lathe which is actually too small for the job but I added a home made "three point steady" which allows it to handle parts this size. I believe other people have managed with a drill. The steel cable is only 2.5mm rather than the 3mm specified. I don't know if it mby nophead - Mechanics
Just made the extruder drive screw. The instructions in the wiki say to use a small blowtorch and plumber's flux. I bought these and found both were unnecessary. It is much easier to use a soldering iron and electrical solder with built in flux. I used a 50W temperature controlled iron but it did not struggle at all so I think 25W would probably be OK too. It might save somebody some money if theby nophead - Mechanics
Jonathon, I think I have come across this problem in the dim and distant past and there is another workaround. If I remember correctly the fact that file has been downloaded is stored in an alternate stream in the file. It is a little known fact that NTFS files can have multiple streams of data. 99.9% of all programs use the first stream and ignore any others. There is a free utility somewhereby nophead - RepRap Host
Well I managed to make the bearings quite easily with human technology although I did make it harder work for myself by using steel rather than brass. This picture illustrates why you can't just make one and cut it in two :- The wiki instructions say to make the drive screw before the bearings but I think it is better to make the bearings first. That way you can try the bearings against the laby nophead - Mechanics
The wire rope is smaller diameter (3mm) than the M5 studding (it fits inside it) and it bends away from the filament so they should not be in contact.by nophead - Mechanics
The number of ways is the number of possible pin positions. Usually the same as the number of pins but sometimes one is missed out for keying on some connectors systems. E.g. suppose you have three four pin connectors next to each other and you don't want people to mix them up. Then you use five way connectors with four pins, each missing a different pin out. You then put blanking pieces in theby nophead - Controllers
The version with the steel rope is the newer "improved" version that has a straight path for the filament. It is to allow stiffer filaments to be used.by nophead - General
I would definitely appreciate dimensioning too. I currently click on each euclidean object I can get to and look at its coordinates and size in the object properties. I then create 2D plan views of the objects in Visio and attach dimensions and ordinates which I then read and type in as Python script for my milling machine. Not quite as tedious as it sounds because all the extruder parts are pretby nophead - RepRap Host
englewood, I might be wrong as I haven't got that far yet but I don't think attaching the heater to the wrong end of the nozzle will work very well. I am not sure how big the temperature gradient down the metal is but the incoming plastic has a very high specific heat capacity compared to metal so it will cool it more than say solder cools a soldering iron bit. Normally the temperature gradientby nophead - General
C compilers don't generally check array bounds, it would be considered too big an overhead on an embedded micro. It's not a "hand holding" language, it is focused on efficiency. Lint can do some static analysis which finds some but not all.by nophead - Controllers
Eric, Sorry, I thought you already had an existing CNC machine with drive electronics. Normally 3.2V motors would be driven from a constant current supply of 24V volts or higher to get fast rise times. Chrisby nophead - Controllers
Eric, Yes, thinking about it, using half of one coil at its full rated current means your low speed torque will be about .7 what it with the original unipolar cc drives assuming they used two coils on at a time. As that was strong enough for milling it must be easily enough for FDM. I can't remember what your original supply voltage was but if it was say 24V then your top speed is probably reby nophead - Controllers
From the wiki: "Note, an interrupt occurring during the timing routine will upset the timing. Shouldn't this disable interrupts??! Ah, actually it shouldn't disable interrupts because the sample time is too long. However if an interrupt occurs, it should set a flag to tell it to disregard that particular sample" Looks like "should" means on the to do list.by nophead - Controllers