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Re: Mechanical Engineering Project related to RepRap - 15 years ago

Quite true, but since this is a Mechanical/Manufacturing Engineering Final year project, Donal has some focused effort and some university backing, plus a certain level of training and skill. A research project like recycling plastic, printable motors or printable circuits is open-ended, opening up a new area - which suits some people. Others (like myself a long time ago) might like a tighter, mo

by DaveR - General

Re: Minimal eletronics needed for repstrap? - 15 years ago

You're correct - the arduino generates step/dir pulses from the G-Code. It is likely to connect to your HCNC OK. Current extruders need three things: Temp sensor - this can be a thermistor plugged into the arduino directly: High-load heater circuit for the nichrome or wirewound resistor heater Drive circuit. Either a step/dir, stepper controller, and stepper motor: Or, a dc motor driver board

by DaveR - Controllers

Re: Things i create and enjoy - 15 years ago

Some nice sword work. I wonder what they'd be like printed out? You could post some designs on Thingiverse :-) Then you can get comments, and you can see photos if people build one! Renoir

by DaveR - Let's design something! (I've got an idea ...)

Re: Jerky stepper motor problem - 15 years ago

Are the drivers getting hot? I ended up with big heatsinks on my driver chips.

by DaveR - Controllers

Re: RepRap Wanted in Hillsboro Oregon - 15 years ago

It sounds like you want a makerbot - a mini RepRap, full kit with instructions.

by DaveR - Wanted

Re: Minimal eletronics needed for repstrap? - 15 years ago

It sounds like your CNC table will be fine - all you need is an extruder you can attach to your CNC head, and the board for controlling the extruder. I'd guess your existing setup is probably fine, if you can hook up an ardunio/sanguino to your stepper electronics. It sounds like you've got a good starting point for a repstrap

by DaveR - Controllers

Re: Mechanical Engineering Project related to RepRap - 15 years ago

Hi Donal. I can't speak for the project officially, but for me it RepRap clearly splits into two main areas: the 3d-cartesian robot, which can be used for CNC machining, reprapping, and a bunch of other purposes, and the plastic extrusion unit - which is specific to RepRap. The robot platform seems to be well-supported and used for a wide variety of projects. The extruder might be a good 'chunk'

by DaveR - General

Re: Ceramacast 675 - 5200 lbs. available - 15 years ago

Sorry, I'm on my own here. Good luck

by DaveR - For Sale

Re: Ceramacast 675 - 5200 lbs. available - 15 years ago

Hi Christine, Yep, you're right about the RepRap. I think most people thought you were just spamming the forums, or suggesting this as a deposition material (instead of the plastic). The problem most of us have is that the nozzle needs to get to over 250 degrees C, and we're using a nichrome wire heater that reaches a bit more than that. Each individual heater (typically one or two per reprap/

by DaveR - For Sale

Re: Buying the right motor in the UK? - 15 years ago

Someone mentioned Astrosyn They sell steppers on ebay, e.g. |66%3A2|65%3A12|39%3A1|240%3A1318|301%3A1|293%3A1|294%3A50 - £35 for four, + £12 postage I've seen a lot of 4 Nema17 steppers a week or so ago - I think they post pretty much constantly. I've not used them myself, but it might be worth a look...

by DaveR - Reprappers

Re: No motors? - 15 years ago

Either use the electronics and steppers from the 'real' darwin, or see if you can scavenge some from printers, scanners, etc.

by DaveR - Reprappers

Re: Intention - 15 years ago

oops. if you put brackets round the link (http://forums.reprap.org/list.php?4) then it doesn't do the magic linky thing I must stop talking in brackets (I do it a lot).

by DaveR - United Kingdom RepRap User Group

Re: Intention - 15 years ago

I'm based in Trowbridge, near Bath and Bristol. You can include a link to your blog by just writing http : // myblog.blogspot.com/ e.g. using the forum, you can add a 'signature' to the bottom of your posts: and in the 'forum settings' you can set it to always add your signature (containing your blog link) There's also a list of builder's blogs - add yourself to the builders wiki page: Pe

by DaveR - United Kingdom RepRap User Group

Re: Intention - 15 years ago

I think it's for anything reprap related that only applies to the UK :-) For example, meeting up, UK-specific shops, discussions that only apply to UK laws or problems. Feel free to post as a builder (or hopefully later as a user!)

by DaveR - United Kingdom RepRap User Group

Re: How do you spend your time? - 15 years ago

Print speed is pretty important : when you've spend 6 hours designing something, every second you're waiting for it to print is extra! Also, moving printing speed from hours to minutes is a big factor in general public acceptance. At the moment, 'you can print a coathook in six hours' is not that impressive: 'you can print out a customised Ipod cover while Eastenders is on' is much better. The

by DaveR - Reprappers

Re: Q for BodgeIt - 15 years ago

You can send a PM (Private Message) to BodgeIt through the forum (See the link above the bottom box or click here :

by DaveR - Reprappers

Re: Q for BodgeIt - 15 years ago

I think bodgeit's blog is here: and That might contain the info you need!

by DaveR - Reprappers

Re: Help on Step Genie Circuit - 15 years ago

If you can add the 'enable' lines will this reduce the current draw? A RepRap rarely uses all three steppers at the same time (the z is only used for layer height), so this *might* help. Sorry, electronics isn't my thing :-)

by DaveR - Controllers

Re: Possible Extruder Design? - 15 years ago

CAPA is also non-liquid, and like soft paste. There's some excellent work by Nophead on how much force is needed and how much the current extruders use, along with the current drive systems: Average results look like it takes at least 5kg (50 N) applied to a 3mm rod to force melted ABS through a 0.5mm nozzle. So, if you like, turning the extruder the other way up, it should be able to lift at

by DaveR - Mechanics

Re: Possible Extruder Design? - 15 years ago

Normally, hairdriers have a series or mesh of nichrome or resistor wire along the body of the hairdrier: wirewound resistors are a high-power version of normal electronics resistors, available from electronics shops, etc ( sorry for the confusion!) I use fireplace cement for extruder elements (it works well) but I've just found which I'm currently trying out. 240C is for ABS (Note that's also

by DaveR - Mechanics

Re: Starter kits? - 15 years ago

Hiya both! You could always add yourself to the RepRap Map (http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=117099291054388532447.0004409098b1c5b712553) and see how close you are to each other / anyone else. Local, physical support is really useful, and you might find someone willing to help with parts, etc. Don't be afraid to experiment a little - it's better to buy a few b

by DaveR - Reprappers

Re: Starter kits? - 15 years ago

Hiya - and welcome to the community :-) I went for the 'easy' option. I really was a novice to start with, so I built the electronics kit from the RRRF first, and then ordered the mechanics from BfB. Now, BfB only seem to do the full kit (but it might be worth emailing them to see if they have plans to do extruder/mechanics/electronics separately). The cupcake extruder looks good - I don't know

by DaveR - Reprappers

Re: Possible Extruder Design? - 15 years ago

Nophead and I have both used Wirewound resistors (http://renoirsrants.blogspot.com/2009/03/new-parts-arrived.html) as an alternative to Nichrome. It can also be found in hairdriers and electric heaters, if you can find an old one (it might be easier to get hold of). Anything that is touching melted plastic (ABS) needs to be SAFE at 240C. This means PTFE, PEEK, and metal are OK: wood is not. Also

by DaveR - Mechanics

Re: Possible Extruder Design? - 15 years ago

I don't mind :-) Happy to help. re: extruder design The best way to find out the problems is to prototype it. It doesn't have to be perfect, use whatever you have to hand: lego, cardboard, nuts/bolts, wood, plastic, sellotape, whatever. Even assembling a paper cutout will give you a much clearer understanding of the design, and things often look different on paper/computer, when you can see th

by DaveR - Mechanics

Re: Possible Extruder Design? - 15 years ago

Hi there - welcome to the RepRap world. To post links try including the http : // for example:

by DaveR - Mechanics

Re: Possible Extruder Design? - 15 years ago

'surface tension' - how small do those holes need to be? Is this a similar idea to the Fab@home syringe system? Sorry for the short post, I'm off to work. I' think more and post later.

by DaveR - Mechanics

Re: Off topic Aircraft Instrument - 15 years ago

Off topic, but have you looked at the accelerometers? There are a number of balancing robots (toy cars, etc) that balance on two wheels, I'm guessing that the logic must be somewhat similar? Just thinking, please shoot me down... :-)

by DaveR - Controllers

Re: Off topic Aircraft Instrument - 15 years ago

IF YOU KNOW WHAT YOU'RE DOING, and think it through, and are prepared to accept the consequences, then it should be OK. You know a lot more about aircraft safety than I do. A reasonable risk assessment should be carried out - write down (makes you think about the answers): what are the likely failure modes? what is the worst failure mode? (stuck trim? continuously changing trim? feedback volta

by DaveR - Controllers

Re: Granule extruder/filament maker - some new thoughts - 15 years ago

We're really glad to have you on board. Good luck with your RepRap and let us know if you run into any issues - we'll try and help. If you have any more info on extrusion augers, then please post - photos are good - because it might help us in the right direction. Thanks

by DaveR - Mechanics

Re: Granule extruder/filament maker - some new thoughts - 15 years ago

I'm in it for the heck of it :-) For me, this is a fun project, very geeky, that fits in with my professional software training and my forgotten Mechanical Engineering degree. It's definitely a hobby activity, and I've got no illusions about that. I don't expect this to be particularly efficient, fast, or practical - It's more interesting that I *can* do this at home. If I manage to produce some

by DaveR - Mechanics