First print attempt. Print was going great until the cold end started grinding the PLA. I'm really happy in how straight the sides turned out though.by Evil Monkey - Polar Machines, SCARA, Robot Arms
Thanks, its definetly a work in progress. I'm thinking about naming it the Armstrong A2 to pay homage to the groundwork layed by ttsalo. I increase the speed from the last video, which was originally set to 30 mm/s. Slicer set to 100 mm/sby Evil Monkey - Polar Machines, SCARA, Robot Arms
Here are the firmware changes thus far: configuration.h scara_seg1_len 82.55 scara_seg2_len 125.07 scara_axis_spacing 85.04 (These dimensions are specific to my machine) scara_axis_y -50 (This is an arbitrary number that I picked. By changing this number and uploading the firmware, I was able to puzzle out that when the print starts, the y stepper motor pulls the arm back, in this case 50by Evil Monkey - Polar Machines, SCARA, Robot Arms
Number 2. if you look close in the video, there is a X marked on the build platform to one side, I placed it there to remind myself that side to side was X movement.by Evil Monkey - Polar Machines, SCARA, Robot Arms
Found a couple of PSU's that would fit and run a heated build platform. SeaSonic SS 350W ATX12V Athena Power AP 350Wby Evil Monkey - Polar Machines, SCARA, Robot Arms
A video of it moving. SCARA 3D Printerby Evil Monkey - Polar Machines, SCARA, Robot Arms
Its Alive! I got it up and moving properly.If you are the machine, the right stepper motor is X, left is Y. I loaded up a simple 1 inch cube gcode and it moved as expected. I will upload a video soon. I believe what scara_axis_y refers to is when the program starts, the machines right arm pulls back 80 mm. The platform orientation is what I thought above.by Evil Monkey - Polar Machines, SCARA, Robot Arms
I think x is side to side and y is front to back, same as how a milling machine is set up. The reason I suspect this is because ttsalo says in his thread that there is a strange sine wave appearing in the x movements and if you watch the video this is the oreintation.by Evil Monkey - Polar Machines, SCARA, Robot Arms
Nothing too crazy behind the sheet metal. Stepper motors are Nema 17, arm ones are geared 51:1, z axis is not geared. Runs on a RAMPS 1.4. At the base there is a 160W PSU that I had laying around from a desktop computer that broke. It's enough to run the stepper motors and a hotend, but not a heated build platform unfortunately. I will take a picture of it without the front facade when I get a chby Evil Monkey - Polar Machines, SCARA, Robot Arms
I thought as much as well, so in my configuration I changed the 25 to 51 to represent the gear ratio of these stepper motors. Now if I could just figure out the orientation of the build platform and which arm(left or right) represents which motor I'd be set.by Evil Monkey - Polar Machines, SCARA, Robot Arms
I will do. I'll update what I figure out.by Evil Monkey - Polar Machines, SCARA, Robot Arms
I have been trying with my arm lengths and base width, but it's not responding as expected. A lot of the code that would be really helpful if it was commented on. Such as which stepper is x and y on the machine (left or right?), what scara_axis_y means and the formula for steps per unit. No idea wear he got 1600, the 25 is presumably from the gear ratio he used, and 360 is a circle. The orientaby Evil Monkey - Polar Machines, SCARA, Robot Arms
I do believe that I see Yukon Cornelius in the background.by Evil Monkey - Reprappers
Thank you nicholas.seward for looking into the function for this machine. I had no idea when I started building this printer that that would be the biggest problem! I had been basing the mechanism off the work posted by ttsalo, he is the person who made the SCARA firmware for Marlin as well as the Armstrong printer. Unfortunetly he does not appear to vist this forum any more. As far as the nameby Evil Monkey - Polar Machines, SCARA, Robot Arms
That's a very nice design.by Evil Monkey - Reprappers
I machined what will be the extruders cold end today. Still need to drill some holes for the mounting bolts and spring, but I think it turned out quite well. The bearing holder will be turned over when in use to retain the roller bearing.by Evil Monkey - Polar Machines, SCARA, Robot Arms
Sat down and drew up the cold end. Should fit nicely behind the sheetmetal with the big green button placed so that it can be depressed to release the filament. Plan to machine it from Aluminium.by Evil Monkey - Polar Machines, SCARA, Robot Arms
Like everything on this machine, it will be custom and a pain. It will be a Bowden style, as you would expect, and the hot end will be attached where the bolt currently resides. That bolt is really just a placeholder until I get the firmware sorted out. Cold end will be tucked away under the sheet metal.by Evil Monkey - Polar Machines, SCARA, Robot Arms
This printer has other tricks it can perform that neither Morgan or Wally can.by Evil Monkey - Polar Machines, SCARA, Robot Arms
I won't be able to run as fast as those machines on youtube due to inertia for sure. I am completely stumped on the firmware, programming has never been my strong point. I have been using the Marlin SCARA fork, but there aren't any good explanations online on what some variables represent. ie scara_axis_y . Homing is a real devil. I have the end stops disabled in pins.h but I don't know where thby Evil Monkey - Polar Machines, SCARA, Robot Arms
Here is a printer that I have been working on for the past few weeks. I used 51:1 geared stepper motors for the arms. There was a bit of backlash, which of course is amplified by the arm movement, so two springs were added to the shaft in order to preload the arms. It appears to be very effective. I'm using Marlin SCARA firmware and have it up and moving. The problem is that I have not been ableby Evil Monkey - Polar Machines, SCARA, Robot Arms
How difficult would it be to adapt Morgans firmware to run a SCARA arm robot like this? Black boxes are the stepper motors.by Evil Monkey - Firmware - experimental, borrowed, and future
This project just popped up on 3ders.orgby Evil Monkey - Polar Machines, SCARA, Robot Arms
Good point. I intend to use them in a similar setup as the Wally. I'm going to see if 2 geared steppers opposed to each other can mitigate any backlash.by Evil Monkey - Polar Machines, SCARA, Robot Arms
I recently purchased two 50:1 stepper motors from a company called Phidgets out of Canada, they were around $45.00 a piece. I haven't tested them out yet, but they don't appear to have any backlash. Could this be a more cost effective solution to harmonic drives?by Evil Monkey - Polar Machines, SCARA, Robot Arms
There should be a new game on here, who can find Ohioplastics new account the fastest. I claim this round.by Evil Monkey - General
He had a tendency to quote historical figures and events in defense of his points. My apologies, but you do post in a very similar manner.by Evil Monkey - General
Quotegoldenmongoose Quotetjb1 You seem to always go against the long standing knowledge of members that have been here more than 15 days. Galileo went against long standing knowledge too. I'm in good company. Ohioplastics, is that you?by Evil Monkey - General
Well done! Is the software completely custom?by Evil Monkey - Polar Machines, SCARA, Robot Arms
Do you have a clear idea of how this would work. If you draw a picture or CAD drawing, I'll give it a shot at machining it.by Evil Monkey - Developers