Hey, Hope you are making progress on this last fix-up. I have been wanting to make this for some time. I had the problem that the github files can't be read in eagle, do you have any suggestions on how to get about that?by LarsK - Controllers
I get how the plug works on that, but what cable will you use with that?by LarsK - CoreXY Machines
Hey, Try to make a sketch on a piece of paper of how you imagine it, there are many designs out there. Generally I think the consensus is that if you do NOT make it very solid then cantilevered is not recommended. If the 300 is print area, then I would say cantilevered wont do. See the G&C printer that use cantileverd in a solid construction: Have you read ? It was a very constructby LarsK - CoreXY Machines
For me the laser does not sound precise enough unless you have some of the expensive Leica stuff. It can probably work, but if you have a dial gauge then I believe this is the best method by far: I am not even sure you need the counter weight because the specs on the linear rails are pretty amazing when you actually start looking into details.by LarsK - CoreXY Machines
Wow, those printed parts you have are so nice. I have seen a lot of printed parts on these forums, and it is usually only when people really really try hard they can make something like that... And you just made it for trial assembling... The brown part that holds the fan, how did you print that? Support material? I am afraid that it will crack because you have the layers going in that directiby LarsK - CoreXY Machines
QuoteFlashsolutions Found this post which addresses many of my same questions. Think I read it earlier but did not look at the photos posted which are of the same diode I have been considering. Still would like to know if inserting a second driver between D9 and driver of the laser will work. I am fairly sure, also as I understand that thread, that if you do it with Fan output you need toby LarsK - Laser Cutter Working Group
Uh, Some people use the STEP pin to control the TTL input because the STEP for the extruder auto scales with the velocity of the printer so if it is moving very fast it gives many step pulses and if moving slow it gives fewer. Sounds nice when written here. Now getting the Gcode to call steps and have that translated proper into TTL pulses which scales to a power we want.... Maybe just putby LarsK - Laser Cutter Working Group
QuoteFlashsolutions Thank you Viktor. I have a couple of concerns still. I would prefer to use Repetier software on a RAMPS 1.4 board. The output would come from D9, the fan control, which is 12V PWM, but I have no idea where I would have control over the pulse rates and lengths. Maybe I would need to use Marlin controller software? Not familiar with it. I assume the controller is whereby LarsK - Laser Cutter Working Group
QuoteA_Designs so going by that chart, if I use 3 IRLB8743 mosfets in parallel with 10 awg multi-stranded wire, mount everything on heat sinks and cool the cabinet, it should be enough to prevent anything getting significantly warm? For attaching it to the heat bed, what about if I scrape off some of the silk screen covering the large copper traces at the bottom and solder the 10 awg cables to thby LarsK - Controllers
Whoa that is some crazy solder. I wouldn't trust that heatbed without a lot of testing. You can connect it directly to your PSU to let it heat up, but be careful, if these solders are as bad as they look you can have so much heat at the interface that it hurts the heatbed. I am not sure how to fix it. I would say you need the wire strands to come flat down to the pad to avoid thermal expansioby LarsK - Controllers
Hey, About the PCB; Yes, it is home made. I have a laser and wanted to use the awesome method of VDX. But my skills in building stuff failed me and my laser refuses to be sharp enough to burn the paint proper. It only makes marks. So I went with the low tech way... The entire process is this: 1) I use Eagle CAD to make the layout 2) Spray a blank PCB board with a black paint. The cool wayby LarsK - Controllers
Hey, sure, as below: and I have to go to Picasaweb to link photos, can't get it to reliably work from Google Photos... Strange... The PCB has feets and all but the power cables are so stiff that I can't turn it and put it on the table but I don't feel like investing the time to fix it when I am moving to Duet anyways.by LarsK - Controllers
Hey all, Thank you for the inputs. It actually answered all my questions. I will use a Sainsmart (or similar) relay so it already have the diode. I will also put the pushbutton to turn on power. It is not so nice that I will have to hold the button for a few seconds, in a future project it would be cool if the push-button drives a Mosfet circuit powered by a small CR2032 battery until poweby LarsK - Duet
Hey, I want my Duet to turn everything off with software. I am unsure how I do this the correct way. I am thinking of doing this: I take the 5V out and put that to the relay and then the ground goes to PS-ON. Is this correct? Next, what would be a good option for a relay? I have the classic Arduino type mechanical relays, like this or I have the FOTEK SSR-25 DA . More; I would like toby LarsK - Duet
Hey, sounds like a solid plan. Test it and see how it works out. The TI CSD MOSFET has its Drain-to-Source On-Resistance given at 4.5V as 2.2 mOhm max (typ 1.7 mOhm). That is at 100A power drain (!). When it is written like that in the sheet it is a guaranteed figure. The curves in the later pages are all "typical" but when it is given in the "specification" part it is trustworthy. So tby LarsK - RAMPS Electronics
hey, If you go with MOSFET and haven't purchased any yet, then you should go with this one I think: CSD18536KCS It has half the on-resistance of the one I am using (IRBL8743). It is a lot more rare also. It seems to be a little rare (the TI one) and you will pay 3.5 USD a piece, but for me it looks to be the best in the market. Otherwise have a look at the Digikey alternatives:by LarsK - RAMPS Electronics
Hey, I power mine with a 50A. I think that was a mistake actually. Should have picked something bigger. It is not good practice to run that close to the capacity of the PSU. Maybe I will pickup a 80A. Heatbed: 30A Heater 1: 4A Heater 2: 4A Nema 17: 5x1.20A = 6A Total: 44 A. Also I think it is wrong to power it with two independent PSUs from a design point of view. Meaning, if you can getby LarsK - RAMPS Electronics
Hey, So it is up and running with the RAMPS. In the end I also put resistors (and LED) on the board so that I can take any 5V and drive it with that. The heatsink still gets hot but I can keep my finger on it without big discomfort so it is within. I used a 3x connector with 15A on each channel and split the power cable leads between them. Then 2 of those in each end. Only used single sidedby LarsK - Controllers
Well getting the high-end relay is surprising expensive; aliexpress.com/item/KYOTTO-SSR-KG1040D-New-and-original-in-stock-ready-to-ship-DC-Solid-State-Relay-40A/1328574617.html Notice that DC42 (a very famous user in here) warned against using the Fotek. If you google them you get a lot of bad stories so seems right.by LarsK - RAMPS Electronics
Hey, I just picked the mosfets that I am using now based on some other people using them here in the forum. I had a shortlist of a few which were all mentioned here in the forum and of those the IRLB8743 seemed the best. Again, I am no electronic expert, but it seems to me, that you can actually not get a Mosfet of the normal sized type that can do 30A without serious active cooling and so. Iby LarsK - RAMPS Electronics
I have the exact same question here: I am going to put 3 mosfets in parallel. I plan on making the circuit this weekend so keep an eye on that thread for my experience. I think your chosen MOSFET will need to be run at 10V or higher to get the required performance. If you look at page 3 figure nr. 7 you see that you are almost in the flat region at 30A with 5V gate voltage. This means yoby LarsK - RAMPS Electronics
I should say to the Chinese LM12 story; The solution is and was (in progress) to re-design the printer to a system that works with the higher quality parts. If you see some particular purpose in two rails then you can stick with that and use a stronger frame. Maybe you want to do PCB or foam milling? Or install that 4xhotend with direct extruder and water cooling?by LarsK - CoreXY Machines
Two rails on the X axis but you only use 2020 profile and M3 and M4 T nuts... That doesn't sound like a rugged design, just sounds like classic over-dimensioning of certain parts. 3d printing is all about choosing the proper parts that fits together strength wise but also that are easy to assemble. With 2x X rails you have all the problems of aligning the rails (they have to be perfect paralleby LarsK - CoreXY Machines
QuoteRodF Dual linear rails on all axis with dual sliders on each XY rail and one long slider on each Z rail. . On the X axis (the one that holds the hotend) this is not necessary. Have a look at Hobbymods thread here in the forum. It was the consensus of everybody that only one rail is needed and he even asked the supplier and they also said this. So you should just install one rail and optimiby LarsK - CoreXY Machines
Quotedc42 The comment about 3.3V does not apply to you, because you have said that you will use RAMPS or Duet, both of which provide 5V gate drive. However, it's not advisable to take too much notice of the characteristic curves published on the datasheet, because they show typical curves at the typical gate threshold voltage, but the gate threshold voltage can vary quite widely between devices.by LarsK - Controllers
If doing stacked pulleys you could do like I just mocked up in this photo: Depending on your profile the hole may be 6mm or bigger and then it may be strong enough to cantilever I don't think you can get it strong enough with just a bolt in a drop in nut and the bearings on that bolt.by LarsK - CoreXY Machines
Quoteamigob There is one thing you really should take care of and that is that if the the wire gets cut or the control board has no power, the fet's need to switch off. Another thing you selected a mos fet with a 4.5V on voltage, realist that you only have 3.3V at the output ( on resistance is very high with 3.3 volt, high power dissipation ). You can try without opto coupler but I think youby LarsK - Controllers
Quoteamigob just put 3 of them parallel with the drain on a large peace of the copper on the PCB and done. No active cooling needed. Also you don't have to worry to much about the 10A per MOS fet pin. Thanks for the input. It confirms what I was thinking, so I think that will be it. I remembered I saw a heat-sink in an old PSU that I opened some time back. I opened it backup and extracted the siby LarsK - Controllers
Hey, Thank you for replies so far. @ BOBC and O_Lampe - If I opt to just use one IRLB8743 with active cooling, would that not be a potential fire-hazard seeing how these things does not have thermal shutdown? If the fan for some reason stops it can be really bad? I prefer intrinsic safe whenever possible.by LarsK - Controllers
Hmm, tried to make test circuits with both options... No good. Both gets really hot. I don't understand the IGBT at all, 2V drop and heats superfast... Hmm... Maybe I set the IRLB8742 in parallel? Divide the load across 3?by LarsK - Controllers