blt3dp's mostly metal delta build - AKA Metal Gear
Posted by blt3dp
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blt3dp's mostly metal delta build - AKA Metal Gear September 13, 2017 02:25PM |
A little back story.
I started in 3D Printing way back when by purchasing a Linear Prusa i2 kit from MakerFarm. I assembled and commissioned it, got it printing as well as it could. A month later, the Prusa i3 came out. The print quality was amazing compared to what I was getting. I immediately had buyers remorse.
Over the years I came to realize that the frame of the Prusa i2 was the main cause of it's inferior print quality. Constructed as 2 triangles made from threaded rod and plastic parts separated by more threaded rod, the frame could barely handle the moving mass of the Y axis moving back and forth without wobbling. It couldn't handle moving the X axis back and forth at all. The mass was too much for it, this was amplified by the fact that the motors for the Z axis were at the top, opposite from where the center of gravity should be. Using smooth rod and linear bearings aligned in a very imprecise manner for X and Y axis caused multiple print issues as did using threaded rod for Z axis. The bearings chatter, and the rods squeak. Using printed pulleys for the X and Y axis as well as printed gears for the extruder meant it could never be very accurate. The endstops being mounted on the smooth rods would slide, requiring adjustment every time I went to print. The RAMPS electronics are not very intuitive. Having to flash the firmware with the Arduino compiler every time you needed to adjust something is cumbersome. In all, like others have said, you spend more time working on the printer than actually printing.
Newer machines have since designed away most of these issues. By having more robust frames created from aluminum extrusion and using plastic only for non structural parts. Using actual linear rails, lead screws, and machined pulleys. Designs are much more thought out as I believe we have learned more over time. Advanced electronics and firmwares allow machines to auto calibrate and require nothing more than editing a text file if you wish to configure something in the firmware. The ability to walk up and print something immediately a real possibility.
I've stood by my Prusa i2, upgrading it to print the best parts for it's replacement. Until now. I will only be using it to print the most basic parts for the new machine that I've been designing for about a year and a half.
I'm calling it Metal Gear. As in the video game. I had a massive collection of Metal Gear stuff that I sold, and am using the profits to build this machine. Also the machine is going to be mostly metal.
I had a requirements that I needed to meet:
1. Metal - No plastic for any of the important parts, frame pulleys, etc.
2. No rods, smooth or threaded - Linear rail only.
3. Ease of use - Needs to be easy to use, configure and calibrate as well as low maintenance.
4. Self contained - No exterior components like power supply, control board, etc.
5. Enclose-able and heat-able - To print ABS as well as aesthetics.
6. Easily move-able - To be easily transported or put away.
7. Efficient space use - Best print size related to footprint. Vertical not so much of a concern.
8. Quiet - As quiet as possible.
9. Speedy - Something over 30 mm/sec
I've actually been drawing up designs in CAD for about a year and a half. I've gone through Cartesians, H-Bot, and Core XY designs. I've determined that a Delta meets all those requirements for me. Here's how.
1. Built from aluminum frame vertices from Robotdigg, as well as aluminum extrusion, and any parts available as metal versions.
2. Linear rails, I chose Igus TS-04-12 rails and TW-04-12 bearing blocks. No recirculating balls to seize, they need no lubrication.
3. Precise build and advanced electronics like the Duet Wifi should take care of this.
4. Enough space to mount everything under the build plate, including the power supply.
5. It will be enclose-able and have a heated bed. The heated bed will be mains powered so the machine can work off a smaller power supply that will fit under the bed.
6. As it will be self contained, with even the power supply under the bed, it will be easily move-able.
7. I found the footprint while about the same as my Prusa i2, makes the most efficient use of space. Giving a 300mm diameter build volume for slightly less space than the Prusa i2.
8. The Igus rails and bearing blocks are very quiet. The stepper drivers on Duet Wifi support 1/256 microstepping and cause the motors to be quiet.
9. With a solid build, I should be able to push the speed.
Here's a link to my CAD model.
delta_reprap
Here's the machine it's replacing. Sorry it doesn't want to display the correct way.
Edited 5 time(s). Last edit at 05/31/2019 10:52AM by VDX.
I started in 3D Printing way back when by purchasing a Linear Prusa i2 kit from MakerFarm. I assembled and commissioned it, got it printing as well as it could. A month later, the Prusa i3 came out. The print quality was amazing compared to what I was getting. I immediately had buyers remorse.
Over the years I came to realize that the frame of the Prusa i2 was the main cause of it's inferior print quality. Constructed as 2 triangles made from threaded rod and plastic parts separated by more threaded rod, the frame could barely handle the moving mass of the Y axis moving back and forth without wobbling. It couldn't handle moving the X axis back and forth at all. The mass was too much for it, this was amplified by the fact that the motors for the Z axis were at the top, opposite from where the center of gravity should be. Using smooth rod and linear bearings aligned in a very imprecise manner for X and Y axis caused multiple print issues as did using threaded rod for Z axis. The bearings chatter, and the rods squeak. Using printed pulleys for the X and Y axis as well as printed gears for the extruder meant it could never be very accurate. The endstops being mounted on the smooth rods would slide, requiring adjustment every time I went to print. The RAMPS electronics are not very intuitive. Having to flash the firmware with the Arduino compiler every time you needed to adjust something is cumbersome. In all, like others have said, you spend more time working on the printer than actually printing.
Newer machines have since designed away most of these issues. By having more robust frames created from aluminum extrusion and using plastic only for non structural parts. Using actual linear rails, lead screws, and machined pulleys. Designs are much more thought out as I believe we have learned more over time. Advanced electronics and firmwares allow machines to auto calibrate and require nothing more than editing a text file if you wish to configure something in the firmware. The ability to walk up and print something immediately a real possibility.
I've stood by my Prusa i2, upgrading it to print the best parts for it's replacement. Until now. I will only be using it to print the most basic parts for the new machine that I've been designing for about a year and a half.
I'm calling it Metal Gear. As in the video game. I had a massive collection of Metal Gear stuff that I sold, and am using the profits to build this machine. Also the machine is going to be mostly metal.
I had a requirements that I needed to meet:
1. Metal - No plastic for any of the important parts, frame pulleys, etc.
2. No rods, smooth or threaded - Linear rail only.
3. Ease of use - Needs to be easy to use, configure and calibrate as well as low maintenance.
4. Self contained - No exterior components like power supply, control board, etc.
5. Enclose-able and heat-able - To print ABS as well as aesthetics.
6. Easily move-able - To be easily transported or put away.
7. Efficient space use - Best print size related to footprint. Vertical not so much of a concern.
8. Quiet - As quiet as possible.
9. Speedy - Something over 30 mm/sec
I've actually been drawing up designs in CAD for about a year and a half. I've gone through Cartesians, H-Bot, and Core XY designs. I've determined that a Delta meets all those requirements for me. Here's how.
1. Built from aluminum frame vertices from Robotdigg, as well as aluminum extrusion, and any parts available as metal versions.
2. Linear rails, I chose Igus TS-04-12 rails and TW-04-12 bearing blocks. No recirculating balls to seize, they need no lubrication.
3. Precise build and advanced electronics like the Duet Wifi should take care of this.
4. Enough space to mount everything under the build plate, including the power supply.
5. It will be enclose-able and have a heated bed. The heated bed will be mains powered so the machine can work off a smaller power supply that will fit under the bed.
6. As it will be self contained, with even the power supply under the bed, it will be easily move-able.
7. I found the footprint while about the same as my Prusa i2, makes the most efficient use of space. Giving a 300mm diameter build volume for slightly less space than the Prusa i2.
8. The Igus rails and bearing blocks are very quiet. The stepper drivers on Duet Wifi support 1/256 microstepping and cause the motors to be quiet.
9. With a solid build, I should be able to push the speed.
Here's a link to my CAD model.
delta_reprap
Here's the machine it's replacing. Sorry it doesn't want to display the correct way.
Edited 5 time(s). Last edit at 05/31/2019 10:52AM by VDX.
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Re: FA-MAS mostly metal delta build - AKA Metal Gear September 13, 2017 02:29PM |
The build has started. This will be built in phases so some of my requirements won't be immediately met. But I intend to get it printing as soon as possible.
I've been doing some prep work before assembling the frame.
Tapped both holes on both ends of the vertical extrusions to accept an M5 screw for the feet as well as the top and bottom plates that I'll have cut later.
Used a jig from Thingiverse to help align the tap to the extrusion. Tap Jig
Doing this in an apartment, so I have the extrusion clamped to my computer desk next to the Prusa i2.
I've never used a tap before, but I used some 3-in-1 oil and went slowly making sure to reverse when I felt the chips building up.
Tapped perfectly, did the remaining holes.
Also printed out a miter tool to assist in cutting my carbon fiber rods for the arms. Delta Rod Miter
Here it is clamped to my living room table with a rod ready to be cut.
I bought 3 rods from Goodwinds. They're the .380, 91 cm pulltruded carbon fiber rods.
And here after they're cut to 300mm. They should be about 340 mm center to center with the rod ends attached.
Edited 5 time(s). Last edit at 09/13/2017 04:03PM by FA-MAS.
I've been doing some prep work before assembling the frame.
Tapped both holes on both ends of the vertical extrusions to accept an M5 screw for the feet as well as the top and bottom plates that I'll have cut later.
Used a jig from Thingiverse to help align the tap to the extrusion. Tap Jig
Doing this in an apartment, so I have the extrusion clamped to my computer desk next to the Prusa i2.
I've never used a tap before, but I used some 3-in-1 oil and went slowly making sure to reverse when I felt the chips building up.
Tapped perfectly, did the remaining holes.
Also printed out a miter tool to assist in cutting my carbon fiber rods for the arms. Delta Rod Miter
Here it is clamped to my living room table with a rod ready to be cut.
I bought 3 rods from Goodwinds. They're the .380, 91 cm pulltruded carbon fiber rods.
And here after they're cut to 300mm. They should be about 340 mm center to center with the rod ends attached.
Edited 5 time(s). Last edit at 09/13/2017 04:03PM by FA-MAS.
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Re: FA-MAS mostly metal delta build - AKA Metal Gear September 13, 2017 02:58PM |
Prepping the linear rail before building the frame. These are Igus TS-04-12 rails that I had them cut at 533 mm long. They had holes for screws so I put a screw in each with an M3 T-Nut on each.
I won't bore you with the build pictures, here's the frame completed. The extrusions I got Misumi to cut. For the triangles, they are 355 mm long, 3x2040 for the top triangle and 2x2060 and 2x2020 for the bottom triangle. The verticals are 800 mm long 3x2040.
Here you see it with the print bed just to see what it'll look like.. It's a 1/4" Mic-6 plate waterjet cut disc. My original design was to have the print bed not extend past the frame. The Waterjet guys wanted $150 to cut it to the custom size I needed. So I had to go with a stock disc off the shelf from another shop.
Jetman stocks 12" discs for $40 which I went with.
http://jetmaninc.com/MACHproduct1.htm
I'll end up truncating the disc at the edges of the frame when I plan to enclose it, but for now i'll use the whole disc.
Also here are the feet that I chose. I chose these because they're readily available at Home Depot. They are rubber "anti skid" and they have a metal disc inside that the screw head goes against so you're not just squishing rubber between a screw and the extrusion.
Edited 5 time(s). Last edit at 09/13/2017 04:01PM by FA-MAS.
I won't bore you with the build pictures, here's the frame completed. The extrusions I got Misumi to cut. For the triangles, they are 355 mm long, 3x2040 for the top triangle and 2x2060 and 2x2020 for the bottom triangle. The verticals are 800 mm long 3x2040.
Here you see it with the print bed just to see what it'll look like.. It's a 1/4" Mic-6 plate waterjet cut disc. My original design was to have the print bed not extend past the frame. The Waterjet guys wanted $150 to cut it to the custom size I needed. So I had to go with a stock disc off the shelf from another shop.
Jetman stocks 12" discs for $40 which I went with.
http://jetmaninc.com/MACHproduct1.htm
I'll end up truncating the disc at the edges of the frame when I plan to enclose it, but for now i'll use the whole disc.
Also here are the feet that I chose. I chose these because they're readily available at Home Depot. They are rubber "anti skid" and they have a metal disc inside that the screw head goes against so you're not just squishing rubber between a screw and the extrusion.
Edited 5 time(s). Last edit at 09/13/2017 04:01PM by FA-MAS.
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Re: FA-MAS mostly metal delta build - AKA Metal Gear September 13, 2017 03:38PM |
Pretty standard so far. Now here's where it gets a little more interesting. I plan on using the Robotdigg carriages at least for now. They have a 20x20 hole pattern for mounting to the bearing blocks. The problem is that the Igus bearing blocks have a 20x15 hole pattern. Now I know there are aluminum carriages out there that have the 20x15 hole pattern, but they don't have the belt tensioners and I'd have to rely on shifting the top triangle to tension the belts. I don't like that.
Here's one of the carriages next to a sample bearing block that I got. You can see the holes won't line up.
Luckily I caught this scenario in my CAD model and I had a sample bearing block. My CAD showed it would be safe if I mounted the carriage to the block and used the block as a template to drill pilot holes, and then drilled with the proper size bit.. So I used my Step Father's drill press with some 3-in-1 cutting oil and did exactly that.
Here they are side by side after drilled.
And finally mounted to a block.
Edited 6 time(s). Last edit at 09/13/2017 03:46PM by FA-MAS.
Here's one of the carriages next to a sample bearing block that I got. You can see the holes won't line up.
Luckily I caught this scenario in my CAD model and I had a sample bearing block. My CAD showed it would be safe if I mounted the carriage to the block and used the block as a template to drill pilot holes, and then drilled with the proper size bit.. So I used my Step Father's drill press with some 3-in-1 cutting oil and did exactly that.
Here they are side by side after drilled.
And finally mounted to a block.
Edited 6 time(s). Last edit at 09/13/2017 03:46PM by FA-MAS.
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Re: FA-MAS mostly metal delta build - AKA Metal Gear September 23, 2017 10:51AM |
Got new carbon fiber with 4 mm ID and am working on assembling the Traxxas. These things kind of suck. I've assembled a pack of 12, 2 were perfect. fairly tight, no play. 2 were looser, yet still no play. The rest were garbage. I'm probably going to have to go through 2 more packs.
Edit: ended up buying a couple more packs and assembling them. I used the hot/cold method as before, but one thing I did was I used a spare one of the plastic pieces to press the others down onto the ball. It helped ensure I wasn't putting weird pressure on the one being pushed onto the ball. I ended up with 2 very stiff joints, with no play whatsoever.
Another thing I noticed previously, is when I would thread the M4 set screws into them, even if the joints were tight, they would become loose. Tapping the rod ends and then installing the M4 set screws prevented this. 12 perfectly tight joints.
Too bad I won't be able to cut or assemble the rods for a bit.
Edited 1 time(s). Last edit at 09/23/2017 07:50PM by FA-MAS.
Edit: ended up buying a couple more packs and assembling them. I used the hot/cold method as before, but one thing I did was I used a spare one of the plastic pieces to press the others down onto the ball. It helped ensure I wasn't putting weird pressure on the one being pushed onto the ball. I ended up with 2 very stiff joints, with no play whatsoever.
Another thing I noticed previously, is when I would thread the M4 set screws into them, even if the joints were tight, they would become loose. Tapping the rod ends and then installing the M4 set screws prevented this. 12 perfectly tight joints.
Too bad I won't be able to cut or assemble the rods for a bit.
Edited 1 time(s). Last edit at 09/23/2017 07:50PM by FA-MAS.
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