Enough spares for a second printer...?  

Re: Enough spares for a second printer...?

have a look at this thread.

Re: Enough spares for a second printer...?

"firmware is 99.99% the actual one (3.0.10). the only things i needed to alter was the pin assignment for the electronics i used (mega 2560 & ramps 1.4 instead of a rambo-mini), the pid settings for my cheap chinese E3Dv6 hotend-clone and its temperature sensor."

So I can use a cheap RAMPS board and all I need to do is adjust the pin assignment? (If using a genuine E3D hot end)

This sounds too easy!

Re: Enough spares for a second printer...?

"firmware is 99.99% the actual one (3.0.10). the only things i needed to alter was the pin assignment for the electronics i used (mega 2560 & ramps 1.4 instead of a rambo-mini), the pid settings for my cheap chinese E3Dv6 hotend-clone and its temperature sensor."

So I can use a cheap RAMPS board and all I need to do is adjust the pin assignment? (If using a genuine E3D hot end)

This sounds too easy!

you don't need only the cheap RAMPS board, you'll need an arduino mega, an LCD2004 shield with adapter for the ramps and some A4988 stepper driver breakout boards (at least 4, if everything went ok with altering the current control voltage supply) as well.

in addition you have to add and alter some of the required hardware:

1st add a little pcb that contains the required RC filters to generate the control voltages for the stepper drivers through 3 PWM pins. and of course, you need to alter the stepper driver pcb's to feed them with the control voltage (instead of the tiny trimpot at each stepper driver).
if you don't do this, you can not choose between a high-power or a silent mode.... and you have to adjust the stepper currents manually (through the little trimpots at the stepper driver breakout pcb).
2nd you need to build a little circuit that fit's into the stepper driver socket for the 2nd extruder, to control the hotend fan.

furthermore you need to replace the plugs for the power supply and the heatbed with stronger terminals... the standard ones will melt, because the heatbed draws 15A.
then you've to replace the polyfuses with (sockets &) car fuses.
and, last but not least, you need to add a heat sink for the transistor that drives the heatbed (otherwise it will overheat).

and, over all: you need to know what you do and you need to have the required skills (i don't have the ressources to lead you step by step through the process & design)!

Re: Enough spares for a second printer...?

I was not necessarily thinking of replicating an i3 MK2, just making use of all the parts. It would be more like a MK1 to be honest!

I'd probably get a mini Rambo if they ever had them in the Prusa shop, but since they don't....

Re: Enough spares for a second printer...?

...I'd probably get a mini Rambo if they ever had them in the Prusa shop, but since they don't....
when you have a look at the shipping costs that prusa charges, it won't make a big difference if you order the board directly from the usa yourself.

Re: Enough spares for a second printer...?

I have a lot of spares from my Prusa I3 Mk1, all Stepper motors, and heated bed. But not enough to build a new Prusa I3, but a home design, oh yes 🙂

I have 32 bit electronics going spare a Duet 0.8.5 , and a spare Arduino Mega with a Ramps board with stepper drivers. I have a spare E3DV6 hotend, I just need a few extra hardware components.

I have built several 3D printer kits over the past 4 years and have gained parts. Two decommissioned .

Re: Enough spares for a second printer...?

I'm leaning towards getting a steel frame and a RAMBO board (for simplicity), plus some rods and screws... I think that's all I need. Can print the rest? 😎

Anyone else gone for a steel frame?

Re: Enough spares for a second printer...?

firmware for ramps and compatible boards at https://github.com/slippyr4/Prusa-Firmware

Re: Enough spares for a second printer...?

firmware for ramps and compatible boards at https://github.com/slippyr4/Prusa-Firmware

nice "branch" for the prusa firmware, would have saved me a few days of "research" for my own clone, if it would have been available a few months sooner .
💡 but I don't care, because I've learned a lot during that research. 😎

unfortunately the whole control of the stepper currents is not implemented, because it targets the standard ramps shield (with an additional mosfet @D7 to control the coldend-fan).
so you have to adjust the trimpots at the driver shields to a fixed desired current combination.

➡ otherwise (like at my own clone) you'll need three unused PWM capable pins at the ramps and some little additional hardware to generate the current-control voltages for the x/y, z and extruder stepper drivers.
furthermore you'll need to alter the stepper shields to control them with the pwm-based current-control voltage instead of the onboard trimpots.

so at this branch, you have no working <high-power> / <silent mode> selection. 😥

Re: Enough spares for a second printer...?

Yep, I realise that. I'm using an MKS BASE board so it's got built in A4988 drivers with trim pots. I've just set the currents to those appropriate for my motors and it's working nicely, although I'm sure not as quietly as the genuine one.

Like you, i'm powering my probe at 12V and it's much better than 5V (mine's not a genuine PINDA though).

I posted the link to my fork merely to help others. I actually did the port work a while ago but I've only published it recently because I've only just got my MK42, which is essential really. And I only just figured out how to register on this forum; i thought it was for prusa customers only.

I've also done quite a lot of work improving the PSU cover and RAMBo covers so they are parametric and can be customised to suit your psu and electronics. You can just about see them in my photo.

Re: Enough spares for a second printer...?

😀 pretty cool. 😛
looks like you are using an LJ8A3-2-Z/BX proximity sensor as p.i.n.d.a.

just got my hands on a few of these to test them with the mk42.
beside the fact that they have a longer shaft, they seem to work quite well to detect the calibration points.

are you using the genuine frame and y-carriage (with ubolts ?) from prusa ?
any experience on how the drylins work ?

Re: Enough spares for a second printer...?

Yes, that’s the sensor - although it’s a 5V variant. Not that it works very well at 5V - I’m running it at 12V and since it’s NPN the output is connected directly to the end stop line on the MKS Base. The height fouls slightly on the hook that acts as a cable retainer so I’ve just snipped it off and it’s working fine.

It’s not a genuine frame, it came from ooznest in the UK but it’s proper water jet cut aluminium. What is a shame is that two of the holes used for the electronics cover were missing (I drilled them) but more importantly the other holes (for steppers, top mounts etc) had been drilled 3mm rather than tapped to M3. So I have ended up opening them up and tapping for M4 (should have done M3.5 really) and modifying the part SCAD files for M4 screws.

I couldn’t find U bolts the right size so I printed bearing holders from thingiverse which work quite well although they are a bit fragile.

No drive gear I could find lined up quite right, in the end I’ve settled on an e3d hobbgoblin which is pretty good but the filament path still isn’t perfect (with a mk7/mk8 I couldn’t load filament without taking the idler arm down, but it’s fine with this) but I haven’t tried any flexible filament yet.

I ordered custom made 320mm lead screw steppers from AliExpress so I haven’t had to modify any Z parts like some people have.

I’m quite pleased with it, apart from that I’m still failing to print “hollow draudi” due to a bit of curling (pla, ma8nku on the crazy overhang part of the neck). I think the part cooling fan really isn’t optimal here, although perhaps it’s my fan rather the the ducting setup etc.

Re: Enough spares for a second printer...?

...
I ordered custom made 320mm lead screw steppers from AliExpress so I haven’t had to modify any Z parts like some people have.
...

so I guess you have the Tr8x4 (2 threaded) trapezoidal spindles, and printed david.t2's trapezoidal nuts.

I've got these for my next project.

did you encounter problems with the polyfuses at the ramps board ? and the connector for the heatbed (our MK42 draws 15amps, which is beyond the specification of the ramps connectors... even so the mosfet can cope it).

Re: Enough spares for a second printer...?

so I guess you have the Tr8x4 (2 threaded) trapezoidal spindles, and printed david.t2's trapezoidal nuts.

I originally used the brass TR8 nuts that came with the steppers. I printed modified X carriage ends because the mounting holes were a different offset. But I wasn't happy with those nuts, there's a lot of backlash - especially with Z-hop. So yes, I printed TR8 nuts. Initially in PLA but the current ones are nylon (taulman bridge)

did you encounter problems with the polyfuses at the ramps board ? and the connector for the heatbed (our MK42 draws 15amps, which is beyond the specification of the ramps connectors... even so the mosfet can cope it).

No, because i'm not using a real RAMPS - i've got an MKS BASE. It's RAMPS pins but it's got support for two extruders so it's already got the mosfet needed for the extruder fan, and it's got the connectors for the LCD without needing an adaptor. And it's good for 12-24V. I think RAMPS is a great standard, but for me, the RAMPS board itself has had it's day. MKS GEN is also a great board, with pololu plugin drivers (the BASE has built in A4988s).

The bed mosfet doesn't even get warm. But then I think my bed is a little down on power (it's a clone, resistance is a little too high). I've upped the voltage to about 14V on my PSU which helps a bit.

Re: Enough spares for a second printer...?

... But then I think my bed is a little down on power (it's a clone, resistance is a little too high). ...

so you've already got your bed from Edward Clifford's indigogo campaign delivered ?
I'm still waiting....

is it dead flat ?

btw. I've got some of these brass anti-backlash nuts in my drawer, waiting for the next project.
they consists of two interlocking brass parts and a spring.

Re: Enough spares for a second printer...?

is it dead flat ?

I have got it, and no, it's not flat. More than 2mm higher in the middle than the edges. When you screw it to the frame, it's a bit better, but it's still unusable. It won't even pass calibration. If anyone wants a warped bed then i'm happy to sell it to them.

I spent ages with it mounted testing and retesting with calibration, and I actually spent quite a long time studying the source code for the calibration. But the long and short of it is that the way the calibration works, with the warp of the board, the side calbration points are detected closer to the edge than they really are, and the calibration gives up because they're just too far out.

I also ordered the autotronix one. Thats much closer to flat and prints quite well, however it's got a higher resistance than the edward clifford one. So neither is perfect. I'm hoping one day to get the edward clifford one replaced but he's not responding to messages, so I'm not sure how lucky i will be.

Re: Enough spares for a second printer...?

...
I have got it, and no, it's not flat. More than 2mm higher in the middle than the edges.

that's why the whole delivery is postponed, it seems that he's actually trying to fix the issue with the warping, together with the commissioned pcb-company.
seems that this crowd funding project would be more expensive as he expected.

just have seen the AutoTronic one (which is mounted at your clone). but it looks as if you need to get in contact with them through facebook to get one (but I'm still one of those who refuse to get a facebook account).

Re: Enough spares for a second printer...?

pretty sure he has sold out now, anyway. he originally ran an indiegogo campaign for them too, but it's closed down now.

Re: Enough spares for a second printer...?

I've now updated the firmware on my github to 3.0.12

No multimaterial support at the moment. I will look into that in the future, but so far the electronics for the extruder multiplexer board isn't publically available and that makes it more trouble than it's worth to try and implement that on a clone.