Rebuilt my printer- Son of MegaMax Lives!
Posted by the_digital_dentist
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Rebuilt my printer- Son of MegaMax Lives! April 05, 2015 12:32PM |
MegaMax was a great printer but there were a lot of things I wanted to change.
First, he was a little too large- barely fit through doorways and required a huge enclosure. Next, I wanted to separate the electronics from the print chamber so the chamber could be allowed to get very warm. Finally, I wanted it all self contained- no more power supplies in a separate enclosure.
For the new design, I wanted to reuse as many of the old parts as possible to keep costs under control. I started with a redesign of the frame and figured out how to make it 8" narrower without giving up any build volume. I was able to reuse most of the 8020 from the frame and only had to buy about 15 more feet (at $2/lb from the scrap yard). The frame became a simple rectangular structure that would be easy to enclose by simply adding side and top panels. I kept the bed, heater, transformer and SSR.
I had to figure out where to put the electronics. It made the most sense to put that stuff under the printer, but then I had to figure out how to access it for service. Then I got the idea of putting the electronics in a drawer that pulls out on ball bearing slides. That meant I had to make the cables extra long so they could still connect when the drawer was pulled out. But what do you do with the excess cable length when the drawer is closed? It seemed like a bad idea to just let the cables drag on the table under the printer, so routed the cables through (and on) a folding pipe that keeps the cables up off the table.
Changes made in the rebuild:
The clear polycarbonate panels keep the entire mechanism enclosed and visible so it can be operated safely in public places where curious people might touch things they shouldn't. I had to find a way to attach the panels that would allow easy removal to access the print bed and mechanism, and settled on using 3M dual-lock tape. It is like velcro but there's no fuzz. The panels snap on and off easily but stay put. A few-hour-long test print resulted in the build chamber getting up to 107F/42C. I'd like it to get warmer so I may add some weather stripping between the dual-lock tape pieces to seal the enclosure a little better.
The LCD control panel talks to the smoothieboard via SPI, so the cables have to be kept very short. I decided that the best way to mount it and the power switch was inside the electronics drawer. That way, when the machine is displayed publicly, there are no visible controls to tempt curious people to see what happens if they flip a switch, etc. I have yet to install either a latch or handle on the drawer, so it isn't really obvious that it's a drawer when you look at the machine.
I used to print exclusively from SD cards before the rebuild. When I was rebuilding the machine, before I got the LCD control panel, I was using Pronterface to control it via USB cable and not happy about it. I was relieved when the LCD board came in so I could go back to printing from SD cards again. Sneaker-netting SD cards to the machine can be a PITA, but it is the most reliable way to print.
Here's the nearly finished rebuild, dubbed Son of MegaMax (SoM), and the electronics drawer:
The machine weighs around 120 lbs/54 kg, and fits laying on its side into a Prius. The fully supported linear guides in the Y axis make it so solid that I have had to level the bed exactly one time when it was installed, and even after transporting the machine to the makerspace laying on its side in the car, I was able to take it back out, set it upright, and start printing without making ANY adjustments.
Overkill? Definitely! Would I do it again? Definitely!
First, he was a little too large- barely fit through doorways and required a huge enclosure. Next, I wanted to separate the electronics from the print chamber so the chamber could be allowed to get very warm. Finally, I wanted it all self contained- no more power supplies in a separate enclosure.
For the new design, I wanted to reuse as many of the old parts as possible to keep costs under control. I started with a redesign of the frame and figured out how to make it 8" narrower without giving up any build volume. I was able to reuse most of the 8020 from the frame and only had to buy about 15 more feet (at $2/lb from the scrap yard). The frame became a simple rectangular structure that would be easy to enclose by simply adding side and top panels. I kept the bed, heater, transformer and SSR.
I had to figure out where to put the electronics. It made the most sense to put that stuff under the printer, but then I had to figure out how to access it for service. Then I got the idea of putting the electronics in a drawer that pulls out on ball bearing slides. That meant I had to make the cables extra long so they could still connect when the drawer was pulled out. But what do you do with the excess cable length when the drawer is closed? It seemed like a bad idea to just let the cables drag on the table under the printer, so routed the cables through (and on) a folding pipe that keeps the cables up off the table.
Changes made in the rebuild:
- Fully supported linear guides for X and Y axes- bought used via ebay, much more compact and precise than the 1/2" round rails I was using
- Ball screw drive in the Y axis- rescued from a pick and place machine at a scrap yard- as noisy as it is precise!
- Smoothieboard controller w GLCD control panel- very easy to use and great performance
- Clear polycarbonate top, side, and back panels
- BullDog XL extruder and E3D v6 hot-end- bullet proof!
- DSP drivers and 32V power supplies for X and Y axes- help smooth out motion of the NEMA-23 motors.
- Modular X and Y axes with screw terminals to connect cables- can be removed and replaced by loosening two screws.
- Liberal use of screw terminals throughout the machine to control connector costs and make servicing easy
The clear polycarbonate panels keep the entire mechanism enclosed and visible so it can be operated safely in public places where curious people might touch things they shouldn't. I had to find a way to attach the panels that would allow easy removal to access the print bed and mechanism, and settled on using 3M dual-lock tape. It is like velcro but there's no fuzz. The panels snap on and off easily but stay put. A few-hour-long test print resulted in the build chamber getting up to 107F/42C. I'd like it to get warmer so I may add some weather stripping between the dual-lock tape pieces to seal the enclosure a little better.
The LCD control panel talks to the smoothieboard via SPI, so the cables have to be kept very short. I decided that the best way to mount it and the power switch was inside the electronics drawer. That way, when the machine is displayed publicly, there are no visible controls to tempt curious people to see what happens if they flip a switch, etc. I have yet to install either a latch or handle on the drawer, so it isn't really obvious that it's a drawer when you look at the machine.
I used to print exclusively from SD cards before the rebuild. When I was rebuilding the machine, before I got the LCD control panel, I was using Pronterface to control it via USB cable and not happy about it. I was relieved when the LCD board came in so I could go back to printing from SD cards again. Sneaker-netting SD cards to the machine can be a PITA, but it is the most reliable way to print.
Here's the nearly finished rebuild, dubbed Son of MegaMax (SoM), and the electronics drawer:
The machine weighs around 120 lbs/54 kg, and fits laying on its side into a Prius. The fully supported linear guides in the Y axis make it so solid that I have had to level the bed exactly one time when it was installed, and even after transporting the machine to the makerspace laying on its side in the car, I was able to take it back out, set it upright, and start printing without making ANY adjustments.
Overkill? Definitely! Would I do it again? Definitely!
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