+1 I think its a great model Rigid,simple and elegant, less parts etc mine has been running for 2 months with no problems. Thanks Nophead for a grand design.by rcs - General Mendel Topics
I am having a bit of trouble identifying what is wrong here. It seem that slic3r is missing a layer. the picture shows 2 parts the one on the left was done with a .5 nozzle and the other with a .35 nozzle . This has been printed ok with skeinforge 45 with no problems. But it has been printed with slic3r V7,V7.1 & 7.2. It appears to not print the perimeter and thus falls apart. it alwaysby rcs - Slic3r
No a pc fan will not draw enough current to load the 5V rail, a 5R resistor will draw about 1A and will get hot, I bolt mine to the side of the PC power supply to act as a heat sink.by rcs - RAMPS Electronics
The Z motors generally turn off between instructions (that can be set in firmmware) the X & Y stay on. If your supply drops to 6 V the I suspect that your pwer supply can not supply the current required. If you are going to use a heated bed you will need a supply to give you about 15 A. I used a PC power supply 550W with a 5 ohm restistor on the 5 V railby rcs - General Mendel Topics
It is also a good idea to load the 5V rail with about a 5R restistor if you are using a PC power supply they need a load on the 5V or 3.3V rails in order to get a stable 12V from the 12V rail the black and yellow cables are all joined up inside the P.S.by rcs - RAMPS Electronics
Nophead Does that mean the the driver will keep the current at say 1A with about .4V on the vref pot and give me more torque but at slower Z speed. If so at what Z speed do you think I could operate at on a prusa. As I also would like to do a Z lift between moves. Thanks for the help.by rcs - General
What are the pros and cons for have the Z motors being wired in serial or parallel when being driven from 12V with 2.8V motors. Thanksby rcs - General
And mine: 1. PC-PSU 2. 550 watts 3. 20 amps 4. 12.5 amps 5. Marlin 6. No 7. Yes, I have 5R load on the 5V railby rcs - Controllers
It might be a good idea to keep the motor wires apart from the end stops and thermistors to avoid any cross talk between them.by rcs - General
I use Bostik all Purpose clear adhesive I find it will stick PLA and ABS and also MDF to PLA etcby rcs - General Mendel Topics
Thanks for the info, that is where I have bought them from before but it would be nice to have another opinion regarding the torque as I will putting these into a Mendel 90 ( Nophead grand design) I have followed his blog for that last 2 years. I have built all the MDF parts and designed all the ABS parts with a 70mm spacing for the X and 30mm for the Z. all with 10mm bearings everything is prinby rcs - General Mendel Topics
Hi Would these stepper specs be OK for a prusa mendel. or would they not have enough torque as I think the V is a little high. Step angle 1.8, Rate Volts 3.4V, Rate current 1.7A, Phase R 2R, Phase inductance 3mH, Holding torque 48oz/in, Rotor inertia 54 g/cm sq Torque .22 kg/cm, motor weight 240g, 4 cables. As here Thanks.by rcs - General Mendel Topics
If you don't have any resistors you could put an auto car bulb across the 5 V rail, say about 25 Wby rcs - Reprappers
I found that on the ali bed I drill a blind hole for the thermistor and use silicone gasket from a car spares shop it is OK up to 625' F. I also use it on the hot end to hold the thermistor in place. I found it much better that fire cement.by rcs - General
If you are using a pc power supply consider put a load resistor about 5R on the 5 volt rail. it usually inproves the 12 V rail. Also if your bed cables are getting warm you will be getting a volt drop there as well. You can check the volts at the heated bed terminals.by rcs - Reprappers
The reason I use a relay (auto 12V 30A with diode) is only to avoid putting the bed current through the tracks on the pc board ramps 1.2. I don't use any heat sinks then on the MOSFET. Rapid switching in not neaded for the heated bed.by rcs - General
I use brass nuts on the lead Z screws and just a drop of machine oil.by rcs - Reprappers
For what its worth. I also use 10 2.2 ohm resistors in a series parallel combination to give an even heat on a 5mm alli bed with glass on top. I think this gives me about 0.9R at 12V around 10.8A which is about 130 Wby rcs - General
I use a 5R bolted to the inside of the ATX. The case will then dissipate some heat from it. You won't notice a difference until you use a heated bed that will draw about 12A But the ATX will be more stable.. Good luck with your build.by rcs - RAMPS Electronics
The value is not that important but 5R can be found here 10W Arcol Aluminium Clad Wirewound Resistor 5R at spiratronics in the UK or ebay. A good read here . It is important to connect a group of the yellow cables together and also a group of black cables to enable to get a bigger current rating, rather than just one yellow and one black.by rcs - RAMPS Electronics
The amp rating can be as high as you like as the machine will only draw the current it requires , ie if you have a 40A power supply and your load only requires 2 A that is all it will take from the power supply. If it is an ATX pc power supply it is good practice to fit a load resistor on the 5 V line of about 5 ohm. This helps keep the 12V line up.by rcs - RAMPS Electronics
I also have used foil around the resistor in the hotend and use silicone that will stand 625F to fix the thermistors to the bed and hotend. I found that fire cement came loose after a time.by rcs - General
I am surprsed that you can heat your bed up to 55C with 2 2.2R in series and get even heat over the bed. I think that 55C would be a bit to hot to hold. But if its working OK thats good.by rcs - Reprappers
I use 10 2.2R in a series parallel combination which is about .85R on a 12V atx 550W power supply with a 5 R on the 5V rail. I am using ramps1.2 and control the bed through an auto relay to take the load of the mofffet. when it get up to temp it switches on/off. my bed take aprox 13 min to get to 110C. what I mean by 1R is the total R of the heated bed to be able to heat up in an acceptablr timby rcs - Reprappers
I use the Arcol hot end V3.1 I think he has a version 4 which is quite a bit shorter.by rcs - Reprappers
4 2.2R in series will give you 8.8ohm ideally you want 1 ohm so the best you can do is put them in a series parallel combintaion giving you 2.2ohmby rcs - Reprappers