Show all posts by user

Re: Blobbing and roughness on vertical surfaces. - 11 years ago

It might be there is water in the filament? That can cause blobbing as the water boils. I wouldn't bother trying full steps, I doubt it is the issue. The blobbing isn't layer-by-layer it's weird, so it might also be the hobbed bolt is a little slippy?

by james glanville - Reprappers

Re: Help in wiring SD card reader to RAMPS 1.4 - 11 years ago

Hi, a few things: DON'T connect the 3.3V to the ramps. There is a 3.3V regulator on your board (the AMS1117), so the 3.3V is an output, not an input, and you don't want to connect 2 similar power supplies to each other. The grounds are all connected together on the ramps board, you only need to connect to one, but more than that wouldn't break anything. You might want to allow the firmware to

by james glanville - RAMPS Electronics

Re: Plotting PCB designs with resist marker - 11 years ago

I had a go: The pictures in the middle are my attempts at making a ramps board (single sided). I just cable tied a sharpie onto my x-carriage, and it worked fairly well, so I imagine a spring loaded head done properly would work very well. I had to tidy up the board by hand very slightly, but that was mostly due to the sharpie wobbling too much.

by james glanville - CNC Routers, Mills, and Hybrid RepRapping

Re: How to clean or upgrade a cluttered Prusa Mendel hot end - 11 years ago

You mean clogged inside? Just heat it up, push some fresh filament in, then let it cool down fully. Next start heating the hotend again, while pulling firmly on the filament when it gets to over about 100C. You'll pull a slightly-molten plug of plastic out, with a load of detritus stuck to the end. You may need to repeat this a couple of times. I do this about every 100m of the cheap filament I u

by james glanville - General Mendel Topics

Re: Hole sizes not right - 11 years ago

I find it easiest to calibrate my printer, then print one of the many items on thingiverse that has a load of different size holes or hex holes. That way you can just find what nominal size gives you the correct fit. I'm not sure there is a perfect way to calibrate a printer, since you have to know exactly how the plastic will shrink (which is contained by infill on external perimeters, but not i

by james glanville - General

Re: CubeX + Rambo = Freedom - 11 years ago

Oh I'm sorry, I misunderstood the problem. Undo the change I suggested. Change: #define Y_HOME_DIR -1 to: #define Y_HOME_DIR 1 That should make the endstop now be the max endstop instead of the min endstop. Hopefully that'll work.

by james glanville - General Mendel Topics

Re: CubeX + Rambo = Freedom - 11 years ago

Change: #define INVERT_Y_DIR false to: #define INVERT_Y_DIR true Also, that's lousy of them. Did you pay by credit card? You might be able to do a chargeback through your card company to get a refund, since you should be entitled to one regardless of what they say.

by james glanville - General Mendel Topics

Re: Slicer couldn't generate the correct gcode for this part - 11 years ago

What's happened is the STL is non-manifold (so not an unambigous 3d shape), so slic3r can't know what to do with it. You can run broken stls through cloud.netfabb.com to clean them up.

by james glanville - Slic3r

Re: [UK[ Taulman nylon 618 for sale - 11 years ago

I might get some at some point, but you should list the weight/length of the filament spools you're selling. I can just make out "1 pound" in the picture but it's not clear, and I don't know what length that means without bothering to calculate it from the density.

by james glanville - For Sale

Re: Endstop problems - 11 years ago

Sounds a lot like you've plugged them in so that they short 5V to ground when pressed. I suspect you want to connect the wires between another pair of two pins out of the rows of three. If you are shorting out 5v to ground, it'll put a lot of stress on the voltage regulator, so don't leave it plugged in longer than you have to while experimenting.

by james glanville - General

Re: extrusion problem - 11 years ago

Looks like you need to get the retraction settings better - that's what's causing the blobs at layer changes. Your esteps/mm look off too - you shouldn't just multiply it by 5 to correct it (assuming you just guessed), you should calibrate it properly, so that when you manually extrude (say) 100mm, that's exactly what you get (measured by how much filament goes INTO the extruder). You can either

by james glanville - General Mendel Topics

Re: Is it safe to take apart stepper motors? - 11 years ago

I've taken mine apart a few times, and not noticed a difference in strength, but I believe it is still bad for them. I'd do what dirty steve suggested, though I prefer to use blu-tack instead to stop the shavings. It's actually easier not to take the motor apart, I just stuff the cracks with blutack, short all the leads together for a bit of friction, and just tap the side of the shaft gently aga

by james glanville - General

Re: Multiplexing stepper drivers - 11 years ago

You could certainly multiplex the enable lines with little hassle, as these are only really toggled to save power. That'd get you to 18 just with a ramps board. If you want to multiplex the step/dir pins you might need to look for a faster MCU, I don't think the avrs could keep up with the rate of data and pin toggling for controlling a huge number of motors.

by james glanville - Developers

Re: Completely autonomous electronics? - 11 years ago

That sort of setup exists and is quite common - I use a 4x20 lcd, rotary encoder and sd card setup with marlin firmware, and my reprap is not tethered to my pc. Admittedly I do have to connect it to flash new firmware, but I hardly ever do this, and I need a pc anyway to generate the gcode and move it to the sd card. The self-flashing firmware would still be a very neat addition to the marlin fir

by james glanville - Controllers

Re: Is it possible to print it in one piece? - 11 years ago

It'd be really easy to make on a laser cutter - just cut hundreds of disks with a small hole in the center, thread them onto a rod, and glue. In fact, it looks possible that was how it was made - the disks look to be roughly the same thickness. Otherwise, printing in two halves would be easy, and gluing along the middle. I think it's one of those things that isn't worth 3d printing in one go.

by james glanville - Competitions

Re: Building a Medel90 Dibond - Nophead. - 11 years ago

Very cool - I'm amazed at the quality of those first prints. How many hours in total do you think you spent building before you started the first print?

by james glanville - Beds/Herts/Cambs RepRap Usergroup

Re: Pricing a print job - 11 years ago

Adding to what Jon said about taxes - does anyone know if you can file a tax return to reclaim money spent on the printer and maintenance costs? I looked here: and it seems like you possibly could?

by james glanville - General

Re: Pricing a print job - 11 years ago

Good point from garyhlucus about shipping - I sell parts about as frequently as I buy stuff, so I can reuse packaging (at the cost of not looking professional, although for me I don't really care). A really really cheap way to do packaging is find some old cardboard boxes, and get some parcel tape, since provided you don't use stuff with obvious logos it looks reasonably pro for nearly free (bike

by james glanville - General

Re: Pricing a print job - 11 years ago

I'd go with 3x the plastic cost (or some other multiple). Way too much hassle trying to calculate build times/wear and tear, as for most models the larger the part the longer it takes. Plus you want some extra to absorb the cost of failed prints, replacement parts, upgrades etc. Still very cheap for the other person too.

by james glanville - General

Re: Is it possible to repair a stepper motor that has internal stressed wires? - 11 years ago

I was interested in finding this out, and there's not a huge amount of information I could find. Lots of posts saying how it used to be an issue/now isn't with new motors, or the other way around :s The only reasonable sounding explanation I found was that the permanent magnets will experience a greater magnetic field gradient when disassembled, which can demagnetise them somewhat. No idea if tha

by james glanville - General

Re: Is it possible to repair a stepper motor that has internal stressed wires? - 11 years ago

If you want to use motors like this - just blob some silicone glue/hot glue around where the cables come out, they'll act like strain relief. Have you repaired it just by holding the wires in a known-good location? Beware that loose connections can fry stepper drivers due to inductive surges. What I do is solder pin headers to the motor, then epoxy the headers to the body:

by james glanville - General

Re: Noobs: Original Replication RFQ here: - 11 years ago

I don't think anyone is really working on a 100% printable printer - since it probably isn't possible: The hotend needs to be printed with something that has a melting point higher than the plastic you want to print, so it can't print itself. Likewise the hobbed bolt has to be harder than the material that's used with it so it doesn't wear. Ultimately, I think repraps at the moment print about

by james glanville - General

Re: 1/2 hp motor driving PLA gears? Crazy? - 11 years ago

PLA gears have a tendency to destroy themselves - the teeth heat up a bit, and become tacky, increasing friction and causing further heating, until you have a large blob of semi-molten gears that get thrown around. I've never printed with nylon or abs, but you'd have more luck with those (even if it still didn't work.). Like konwiddak said, just cast them if you want to use printed pieces.

by james glanville - General

Re: Z axis binding - 11 years ago

If you find the z shafts are wobbling around - perhaps the hole in the x-ends is not quite big enough? I know I had to slightly enlarge the circular hole whether the threaded rod goes to stop binding happening. You might also want to check your motors are correctly positioned and not a little bit to one side.

by james glanville - Mechanics

Re: stepper question, precision - 11 years ago

Microstepping isn't very accurate - you won't get an exactly linear angle change going from one full step to another through all the in-between steps. You'd probably be better off having a fixed angle mirror that you slide along an axis, or maybe using a galvanometer if the mirror is light enough.

by james glanville - Stepper Motors, Servo Motors, DC Motors

Re: Print with PLA or ABS - 11 years ago

After many, many hundreds of hours, my pla extruder had slightly warped in the middle (quick fit, only held be the ends). It still worked fine, and I replaced it recently for a different reason. YMMV, but it should work ok.

by james glanville - General

Re: USB cable starts overheating when Power Supply is turned on - 11 years ago

Check for shorts near that driver socket. There's probably a short between 0v/5v and 12v/1a/1b/2am/2b

by james glanville - Controllers

Re: Slic3r doesn't handle hole in box interior - 11 years ago

Cool glad you got it sorted. There's a useful python script to automate the process instead of using a web form:

by james glanville - Slic3r

Re: USB cable starts overheating when Power Supply is turned on - 11 years ago

Wow, you've been really, really lucky to only have one driver broken. I'm amazed the motherboard of the computer isn't broken, or that the Sanguinololu isn't complete toast. I can only think that the broken driver failed short-circuit, saving the rest from reversed polarity.

by james glanville - Controllers

Re: Weird issue! Stepper motor runs when I touch IC!!! - 11 years ago

Have you made sure you have set the configuration for sprinter to the correct electronics that you are using? It sounds like the pin assignments are wrong, and the X axis is connected to a high-impedance output so static is enough to make it jump.

by james glanville - Controllers