Show all posts by user
Cartesian XYZ machines with frames made of extruded aluminum, T-Slot, Makerslide, and more. See http://reprap.org/wiki/Category:Aluminum. Previously named "Extruded Aluminum"
Re: New arm design for Simpson style printer. - 12 years ago
With the bottom pulley offset the line length is equal on both sides of the equation. You can add loops to the offset pulley just as Nicholas has in his schematic. If you apply loops equally to both the top and bottom pulleys the line remains equal in length. I'm not understanding how a loop corrects for non-linearity. Please point me to a scholarly paper that will help me understand the magiby A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
Routing: Shift the lower pulley down an amount equal to it's diameter. This arrangement is equivalent to the upper pulley mechanical advantage. Eliminates the 1.5 wrap, and associated issues. A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
Routing: You could add two additional pins to the lower pulley/pivots as a workaround to the 1.5 wrap. Or: I like the idea of small ceramic pulleys riding steel shafts. Ceramic fishing eyes might be a cheap option in bulk. Note: there is an OD grove on the ceramic fishing guides that the metal snaps into. The line would run in this grove. I don't understand the use of the spring, or it'sby A2 - Delta Machines
Re: You pay Staples $100 a month to sell your designs - 12 years ago
Why is Staples having a 3D design challenge on a competitors web site?by A2 - General
You pay Staples $100 a month to sell your designs - 12 years ago
Staples Easy 3d source: A2by A2 - General
Re: Water cooled all metal hotend - 12 years ago
@Xabbax I like your water cooled extruder! I don't see a hose clamp on the coolant hose. Plastic creeps over time, the coolant hose could separate, and leak water. To be safe add a hose clamp to the flexible tubing. If your microcontroler is located under the build table it could short if your system develops a leak. If you're worried about the additional weight of the hose clamps, drill crossby A2 - General
Re: Printing nylon--new Garolite LE (McMaster 8474K141) very warped! - 12 years ago
I wonder if spray on hair would work... lol I read that it contains tiny fibers. Heavy paper stock sounds good, but I think it will delaminate? Maybe a sacrificial sheet of paper glued to a plate of glass will work? A2by A2 - General
Re: Printing nylon--new Garolite LE (McMaster 8474K141) very warped! - 12 years ago
Garolite uses a thermoset resin, it's not going to self level with heat. Idea: Glue the Garolite sheet to a thick plate of glass with Epoxy (JB Weld), Polyurethane, Silicone (Household Goop). Sandblast, acid etch the glass so the glue can grip the glass. A cheaper grade of glass is easer to acid etch (soda glass?). Verify the flatness before gluing, to do this: Clamp the Garolite down with thby A2 - General
Re: Grounded Experimental Delta Printer - 12 years ago
Thanks for the NYMF update. Line winding technique to increase driving force: CoreXY, did it look like this? Simpson line routing? I'm guessing what is actually going on. Provide us with a routing diagram of how the line is strung around the drum and bolt-pulleys with the tensioner. Mechanical advantage? Is there a limitation that prevents the drum diameter from being reduced to Dia 0.40” iby A2 - Delta Machines
Re: Grounded Experimental Delta Printer - 12 years ago
@jason.fisher “Or maybe something about the design is naturally generating a static field that attracts extra dust?” I was thinking along the same lines as you. It's possible that a static electric charge is being generated by the rocking surfaces of the arms, and/or by the back and forth motion of the fishing line over the steel bolt, and against the surface of the plastic arms. A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
@Nichloas, and beta testing team: I'm interested in learning more about Simpsons performance/specifications/capabilities, etc, and a few more ideas. Orientation bolt-pulley: It looks like both Simpson No1 and No2 have reversed the pulley (bolt) orientation, and now have the line wrapping around the threaded portion of the M8 bolt vs. the smooth section of the shank, is this correct? I assume thby A2 - Delta Machines
Re: RepRap 3DR Delta printer Released - 12 years ago
Thank you for the replies! A2by A2 - Delta Machines
Re: RepRap 3DR Delta printer Released - 12 years ago
I'm not able to locate a BOM. What is the source of this idler bearing and the RepRapDiscount Hall effect end-stop? Missing link: 3 x Hall effect end-stops (I'm using RepRapDiscount versions, here) What supporting electronics are required for the Hall effect sensor? Tks. A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
The adjacent article to the bending radius describes how to design a pulley (sheave) for braided line. The diameter of the pulley is 8 times the rope diameter, and is mated to a round grove in the pulley. So the minimum bend radius is not what we are after, it's the diameter of the pulley. Dia of pulley/bolt/nail, etc: 0.02” inch x 8 = 0.16” inch (4.0 mm). A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
String pulley bend radius: Braided line can run across an acute angle fairly efficiently. Pulley Diameter: If the diameter of the braided line is .02” inch (.5 mm) x 3 = Dia 0.06” inch (1.5 mm). You could use a carpenters nail as the pivot. A piece of 304 SS IV tubing could be slide over the nail to act as a bearing/pulley. You could cut short pieces and flare the ends to trap the line.by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
@DaveGadgeteer You bring up some valid points. I'm trying to think of a hack for this. tks. A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
MicroSwitch vs. Hall effect sensor: I've read some where in these forums that the software needs to me modified just a little if you replace a microswitch with a hall effect sensor. Do you see any issues if the microswitch was exchanged with a hall effect sensor? I've only had bad experiences with microswitches on industrial equipment. They always drift out of calibration, it's not possible tby A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
Just an idea. String crossing issues: I'm wondering if a thin free floating 3D printed plastic bearing would help with string organization? My first thoughts it will bind up and the string will cut the plastic in half. Steel would be my first choice. A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
@Nichloas Looking at Owens video, I noticed the leveling switch or the max extension switch, I'm not sure what it's called or doing. It looks to be a Hall effect switch/sensor, is this correct? I'm not able to locate the switch in your BOM. I down loaded the BOM a month ago, so maybe mine is out dated? To ensure stability of the sensors, I'm wondering if it would be helpful to pot the switcheby A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
ha ha Oh Nooooo Mr. Bill, watch out!by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
@Nichloas your label suggestion is spot on! I've written a lot of instructions for products. For legal reasons I add a leading statement BEFORE my instructions, and it went some thing like the following: Instructions: 1 Follow your facilities protocols. 2 “Then” insert your instructions and warnings “here”. 3 ... Some lawyers say... the statement “Follow your facilities protocols.” shifts theby A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
I understand the design process that you have gone through, and I figured as well that your design is pretty much complete, that's why I wanted to say a few things about the design today. I think you're doing a great job, and on the right track. Gummy bears: Seeing the exposed mechanics of it's operation is intriguing. I'm am curious what happens when some thing falls in between the teeth (e.by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
It's nice to see it all come together. I like the rolling motion, looks solid. A few comments about curb side appeal, etc..: 1. Gear rub test: add a small amount of Prussian blue to the gears to see where they are rubbing. Maybe they are not doing what you thing they are. 2. Product validation if you dare? Spray some hair product onto the gears, then add a gummy bear, and some beach sand. Ifby A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
New arm look great with the motor on top Just curious, are you cutting (swept cut/extrude) the round root/crest gear profile based on a plane that is set "normal to curve" of the helix? (SolidWorks jargon). Or is your profile sketch plane one of the default planes? A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
A few more tensioner ideas: Belt Tensioner for printrbot GO - Y axis By ei8htohms, published Aug 18, 2013 Belt terminator By chowderhead, published Nov 24, 2012by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
3M Anti-Slip Tape will be a test substitute for the herringbone gear. The lateral, axial, rotational grip seems adequate. I think a coarse sandpaper could be substituted. 4” inch wide by 12” inch long, adhesive coating, cost $2.79. @0.70” inch wide by ~9” long, you need ~2 feet, total cost $5.58. A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
Another idea for a string tensioner... Printrbot Simple x-axis tensioner by Tshawkins, published Aug 29, 2013by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
@jason.fisher I did a search for build log in the reprap wiki but I'm not seeing any thing. Maybe it has another name, most likely I just don't understand the wiki The word RepStrap came up in a search, it seems to be close to what I'm working on. But I don't know where to go from here with it. A2by A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
@Nicholas Correct, that model was thrown together in about 6 minutes I envision that a few crisscrossing of the string around the winching screw would anchor it to the screw so it wont slip during tensioning. Do you think the screw will be able to pull the string tight? Herringbone gears vs. cycloidal gears: I like the idea of replacing the involute profile with a rolling (lobed) profile. Poby A2 - Delta Machines
Re: New arm design for Simpson style printer. - 12 years ago
Twine tensioner idea: This requires two holes in the arm, and two drywall screws. 1 Wrap the twine around the first drywall screw. This is your winch. 2 Pass the tag end of the twine through, and out the other side of the second hole, and apply tension to it to hold it in place. 3 With a screwdriver winch the string tight. 4 When sufficiently taut, place the second drywall screw into the sby A2 - Delta Machines