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Re: 3 Extruders 1 Hotend Colour mixing - 10 years ago

Thanks Xabbax. Yes, can you post the OpenScad code. That would be useful. The tubes look to be at about 45 deg. Is that right?

by dave3d - General

Re: 3 Extruders 1 Hotend Colour mixing - 10 years ago

Thanks Xabbax. I visited your website. I like the welding nozzles idea. Couple of further questions:- - what is the centre hole in the heating block for? - is the water cooling by natural convection or forced circulation with a pump? If so what kind have you used? I would like to build one. I have tried twin nozzles with a Bowden setup on my OrdBot. The problem was getting them level. Your n

by dave3d - General

Re: Power tools for cutting aluminium - 10 years ago

Use an angle grinder for cutting aluminium but with a blade made for cutting stainless steel. It is much better than using a normal metal cutting blade. It goes through it like butter. You can then true up the faces with a bench mounted belt sander.

by dave3d - General

Re: 3 Extruders 1 Hotend Colour mixing - 10 years ago

Yes. I think you are right Feign. Water cooled it is. Maybe silver soldered together? I want one.

by dave3d - General

Re: 3 Extruders 1 Hotend Colour mixing - 10 years ago

Wow. This has got to be the way forward. So light and compact. Questions: - are there no PTFE liners in the tubes? - I assume you are using 1.75mm filament, are the stainless tubes 2mm id? - are the tubes a press fit in the hot end? - I can't see what the central tube does. You are using 3 colours, right? Looks like 2 stage heating element. Is it soldered to the brass fittings on the other tu

by dave3d - General

Re: Fume Extractor - 10 years ago

I have found a big difference in ABS quality. I have now given up on black because of all the regrinds they put in it. The smell was awful. I can't find a good black. Don't buy too cheap would be my advice. I now only use Jet ABS from Amazon. My printer is in the living room and there is zero smell at 230 deg C. No fume extraction, windows closed but door open. I have used yellow/green/blue/re

by dave3d - General

Retraction Problem - 10 years ago

I have changed from Marlin firmware to the latest Repetier firmware on my OrdBot. I am slowly optimising the settings and getting it printing but I still have a problem getting retraction to work. I have a Bowden setup and I need to use some retraction. Using Repetier Host for example on the manual setting, extrusion works OK in the right direction, but if I try retraction on manual it continues

by dave3d - Repetier

Re: A4988 Stepper Driver Calibration - 11 years ago

Thanks. So I need to be somewhere around 0.65v to 0.75v I guess ?

by dave3d - Reprappers

Retraction Problem - 11 years ago

I have just changed from Marlin firmware to Repetier firmware on my OrdBot. The Repetier setup webpage was great help and it seems to work seamlessly now with Repetier Software and Slic3r. Slowly working through the optimum settings, however I still have a problem with retraction. I have a Bowden setup and Marlin previously worked OK. The Repetier firmware now seems to reverse the retraction.

by dave3d - Repetier

A4988 Stepper Driver Calibration - 11 years ago

I have just fitted a new set of G3D A4988 drivers to my OrdBot (Nema 17 motors / Arduino Mega / RAMPS 1.4). I have calibrated the X and Y steppers with a volt meter and they work OK (around 0.36v). However, the Z axis is proving more difficult to set up. It is easy to get the motors buzzing. I am not clear on the voltage settings for the Z axis stepper which has two motors connected to it. Can

by dave3d - Reprappers

Re: Where to get 20x20mm aluminum extrusion - 11 years ago

To order from Misumi in Europe, you just need a business address. You do not need to be registered for VAT. As mentioned previously, they will not supply to individuals (I am in the UK and think their offices are based in Germany). One way round this is to order through work if you have a friendly employer. If all else fails, set up your own limited company. Cost me about 12 GBP. I made enquiri

by dave3d - Extruded Aluminum Frames

Re: Printing ABS on glass without any additionnal stuff - 11 years ago

I have found a domestic kitchen chopping board which is made of toughened glass with a nice dimpled finish on one side. It is also conveniently 200mm x 300mm x 4mm. I will try it out on ABS.

by dave3d - Reprappers

Re: Hardware Emergency Stop - 11 years ago

Not quite the same thing, but I have wired up a smoke alarm to cut the mains power to the printer. It has a test button which allows it to be activated manually, so in effect it can act like an emergency stop if necessary.

by dave3d - General

Re: dual extruder questions - 11 years ago

I would agree. Build a single extruder printer first and debug it. That in itself is a considerable amount of work. Once it is working well, modify it to take twin extruders.

by dave3d - Reprappers

Re: Fab Labs - 11 years ago

Thanks vegasloki. It sounds a great idea for small startup businesses. However the monthly membership fee makes it too expensive for individuals I think. Maybe joining a 3D printer club that has membership of the workshop is the answer. I like the idea of training classes before being let loose on the equipment.

by dave3d - General

Fab Labs - 11 years ago

A Fab Lab (digital fabrication laboratory) has just opened near where I live in the UK. It was an idea conceived by an MIT professor to enable people to get cheap fabrication of parts and own designs using advanced digital manufacturing technology such as CNC machining and 3D printing. Apparently there are now 150 or so around the world. Anyone used them and what is the low down before I pay the

by dave3d - General

Re: What is the maximum bowden tube length admissible? - 11 years ago

I am using 1.75mm on my OrdBot. I tried to keep the Bowden tube as short as possible at 350mm. If you thread the filament through the tube and push and pull it at one end, you can see how much hysteresis there is. I am using a geared Greggs Wade extruder and the force on the filament is quite considerable. I also use a lot of retraction.

by dave3d - Reprappers

Re: dual extruder questions - 11 years ago

I have already tried that. I mounted two jheads together using a Bowden setup and the nearest I could get them was 50mm apart. However his means the bed width available for two colours effectively looses twice this distance i.e. it is 100mm narrower.

by dave3d - Reprappers

Re: Can i buy a replacement mosfet at radio shack ramps1.4 - 11 years ago

I am waiting on an external solid state relay to power the heatbed from the Ramps board. Hopefully, It will take the current and heat away from the board. I think it is a better way to go. Mine does get very hot.

by dave3d - General

Re: USB Device Not Recognized after unplugging?? - 11 years ago

If I shut down Repetier first before unplugging the USB lead there isn't a problem. If I just pull out the USB lead when Repetier is running, I get "USB device not recognised" when I plug it in again.

by dave3d - Reprappers

Re: QU-BD Problems - 11 years ago

I built an OrdBot last year and made the mistake of fitting a QU-BD mbe extruder. I had no end of problems trying to get it to work. I even drilled it out and fitted a ptfe liner. Load of junk. I abandoned it and decided to go with a tried and tested design. I now have a bog standard Wade's extruder and a jhead hotend from hotends.com. They were selling a design that basically did not work str

by dave3d - General

Re: Whats the best grease - 11 years ago

Silicone grease would probably be OK for this application. It is nice and clean to use.

by dave3d - Reprappers

Re: ABS and Kapton tape- all the same? or? - 11 years ago

maddog7: I have got two different spools of black ABS. One I can't use because of the smell. It is overwhelming. I got it on Ebay and I think it is made in China. Get what you pay for I think. The other is made by America Instrument which I bought on Amazon. Other colours have been fine but the black appears to have lumps in it as it comes out of the extruder. The layers also don't flow into e

by dave3d - Printing

Re: Question: Polyamide pneumatic tube for Bowden? will work? - 11 years ago

A Bowden cable for a 3D printer needs to be anchored securely at both ends. When using a lot of retraction there is a strong push/pull force on the tube. The tube also needs to be a good fit for the filament so the filament does not have a snaking effect inside the tube causing slack in the system. Unfortunately only standard sizes are available so I had to use 2mm id ptfe tube for 1.75mm filamen

by dave3d - General

Re: dual extruder questions - 11 years ago

I have been struggling with two extruders on my OrdBot. The main difficulty is being able to adjust the height or Z calibration of each extruder independently of each other so they can set dead level. If they are not dead level the nozzle on standby can hit the print. Reduced X axis width as you have mentioned is a problem. Having them one behind the other in the Y axis direction might be a so

by dave3d - Reprappers

Re: Need advice on Thermistors - 11 years ago

You can get the proper thermistor here: I bought half a dozen as spares. Quick delivery.

by dave3d - Reprappers

Re: Question: Polyamide pneumatic tube for Bowden? will work? - 11 years ago

I have converted my OrdBot Hadron to a Bowden setup. I used 2mm PTFE with 1.75mm filament. As mentioned the advantage is the very low coefficient of friction for PTFE. Don't know where you live but it is readily available on UK Ebay.

by dave3d - General

Re: ABS and Kapton tape- all the same? or? - 11 years ago

maddog7: my thermistor is set in a standard RepRap 200 x 200 bed. The 6mm glass is just clipped on top. Often my ABS sticks too well and I can't get it off. I apply the juice with a paintbrush as it is heating up, usually between 70 and 100 deg C. Often good for several prints, it just needs touching up if doing the same print in the same place. How are you applying the Kapton? I spray

by dave3d - Printing

Re: 3D App for Iphone - 11 years ago

OK. Thanks tubarao. I won't be buying an iphone anytime soon.

by dave3d - 3D Scanners, Book Scanners, and Optics

Re: ABS and Kapton tape- all the same? or? - 11 years ago

I use diluted ABS juice on top of Kapton tape applied to 6mm glass with bed at 110 deg C. Juice made by dissolving ABS the same colour as the print object in acetone. I then decant the saturated solution into another container and dilute it down to about 50% strength with more acetone. Extruder set at 235 deg C. I adjust my Z axis to squash the first layer down.

by dave3d - Printing