Ok Guys - I have 9 stepper motors from Zach. 3 from the 1st batch and 6 from the last batch. I have included a picture of my test setup so that you can see what I did and how I did it. Steel Plate is 3/8" by 3" by 12". The holder for the measuring device is a magnetic base that when turned on I cannot move short of a hand sledge (5 pound hammer). The stepper motor was held in place with a Cby bobt - Mechanics
Guys - this kind of thing is very common in the manufacturing world. Any kind of screw will have backlash in its movement because if the nut is tight enough that there is no backlash then the nut will lock into the screw and seize. The way to fix this is if you must move in the reverse direction then you must move further than the about of backlash is. (IE. if there is 1.5 mm of backlash in aby bobt - Mechanics
I think that anyone that uses Zack's fantastic build instructions to make a "Seedling" ought to donate 10 dollars to the RRRF (even if we don't all agree about everything) to help build the funds necessary to allow them to purchase the components we all need to buy to build one. Zach has done one great job of creating a set of instructions that even my grandson can follow and he is only 8 yearsby bobt - General
One other note: to retain the coupling to the stages use a 1/4" copper pipe strap. If you are worried about corrosion a single wrap of any colored electrical tape will separate the two metals. But if you use the 1/2" galvanized pipe strap from the BOM then the coupling and a very small plane will go thru at the same time (please note that I did say "very small" plane). Just thought you might wby bobt - Mechanics
Yahhhh--- I have downloaded the files and started printing them out on standard paper 8.5 x 11 (letter size). It is nice that Zach put at least one measurement on each page. BECAUSE like most people I forgot that my printer was setup to make the stuff fit on the page and when measuring got the wrong size. REMEMBER - Don't have the printer do any scaling of the printed page or it will be WROby bobt - Mechanics
OK - Zach has updated the "Seedling" build instructions. We now have pictures of what the parts look like and some of the initial build instructions on how to put everything together. YAAAHHHHHH........by bobt - Mechanics
Guys - not to rain on your parade but I just found this on one of my tech mailing list. Sorry but it appears there is no video on Skype for now.by bobt - General
Zach - I am not worried about the length. I bought 2 8 foot pieces of channel so length is not a problem. Besides I want to make 2 Seedlings right away. Which means another trip to ACE Hardware (5 minutes away) for another piece of metal. Those folks just love me there. Also fantastic service. Have to beat the kids off with a stick for service. Walk in the door, 1st question do you need anyby bobt - Mechanics
Love the method of connection. But one question? Electrical connections fit where?by bobt - Plastic Extruder Working Group
The 1/2 inch parts is what I received in my order when I purchased. You will have to drill out the hole in the flange to fit it. But the list needs to be corrected because 1 inch parts just will not work.by bobt - Mechanics
I agree that the forums got away there for a while. But I think that RoundSparrow has a point that since Darwin/Mendel are so different from Seedling that separate forum for those unique things might be a better idea. But less not change things real fast until some discussion has been done here as to the best method to do that.by bobt - Administration, Announcements, Policy
Please do the part about measure twice and cut once. I just measured the distance between the base pipes on my "Seedling" and found that the distance is 22 15/16" center to center. Which means that my X supports need to be longer than 21 inches to work. If you neglect to do this part you should probably expect to see the air turn blue around your work. Please make sure that small children areby bobt - Mechanics
I see on the list of parts for the McWire that there are 5 mm Bolts, Washers and Nuts. What are these used for? The 5/16" parts are used for attaching the skate bearings. The 10-24 screws are for attaching the rails to the stage. Also does anyone have the general size for the X, Y and Z stages as getting the dimensions from the autocad drawings is not a small issue. Also while we are listingby bobt - Mechanics
Started chasing stepper motors - Nema 23 156 oz-in 1/4" shaft Webtronic - $24.95 qty 1 Spec sheet: Circuit Specialist - $24.95 qty 1 Spec Sheet: I just chased google for : nema 23 stepper motorby bobt - Mechanics
I checked the site Tuesday and the new stepper motor order was in and online. I ordered 6 and Zach shipped them yesterday.by bobt - Mechanics
RoundSparrow - (Sigh) I will respond this once to your issues. "In case you haven't been paying attention, Zach himself has expressed some concern over the clause. Second, Zach has done things like innovate some new electronics outside of the board with what I consider to have good results. Do you suggest quitting every group you are involved in because you object to how it is run? Feedback anby bobt - General
RoundSparrow - If the operation of RRRF bothers you so much then send ZACH/RRRF an email resigning your membership in the group. Zach is responsible to the Board of RRRF for his operation of the site/foundation. We (not board members) have no voting or control of the operation. Since RepRap is an open source project all of the information about the parts used and their details have been made aby bobt - General
Here is the data right off the RRRF site. This is a "KL23H251-24-8B" 8-wire NEMA 23 stepper motor with dual output shafts from Keling Technology, Inc. It can be wired in unipolar, bipolar-serial, or bipolar-parallel modes. It is compatible with both generation 1 and generation 2 stepper driver boards. You can view the datasheet here, and the torque/speed curve here. You will need 3 (three) ofby bobt - Mechanics
Gentlemen - Back to my original issue - the cure is to create a 2mm lip on the outside of the barrel and a matching relief in the clamp so that there is an edge to carry the pressure load and not just a grab of the barrel to hold it. Both changes can be made by using a barrel 4 mm greater and machining off all but the lip and forming the clamp creating the recess. This is really very simple engby bobt - Plastic Extruder Working Group
I found the tools list again. Just to close the loop the tools are listed on this page:by bobt - 3D Design tools
Might you consider that this is a version 0.5 of a repstrap. I really like their construction techniques. Also were can I get some of those parts..by bobt - General
I have AOI and find to be non-intuitive in operation (what do I poke at now). I already have autocad 2000 and wonder if there are translators out there that will take the dxf file and put out a stl file. I need to use autocad for the engineering drawings for the master project I am working on. The list of tools I found was a good basis to evaluate from. I know that the site is going under a lby bobt - 3D Design tools
At one time this site had a list of 3d tools. And now I cannot find it. Could someone with site access find it and put the links backup.by bobt - 3D Design tools
I have just received the parts for my 2 extruders. Upon examination of the instructions on how to build the extruder there appear to be a lot of assumptions about knowing how all the parts fit together. Is it possible that the instructions be redone showing the addition on no more than one part at a time so that anyone can assemble the extruder. My reason for requesting this is that I have jusby bobt - General
I have seen in other posts that there is a problem with the PTFE insulator barrel (D) coming out of the extruder housing clamp (A) because of the pressure used to force the HDPE into the melting barrel. All that is needed to correct this problem is to put a 2 mm groove in part D about 5 mm wide down 7 mm from the non-threaded end. On the part A (clamp) put a ridge inside of the barrel clamp areby bobt - Plastic Extruder Working Group
Rick - I do have a request. If after your class has generated the drawings can they be put into pdf format. That way they can be posted. Anyone will be able to look at them. Also we do need them fully dimensioned.by bobt - Minnesota Twin Cities RepRap User Group
Lewis - I have gotten the electronics built and tested. I have built the pipe frame for real this time instead of just screwing the things together. I have ordered 2 extruders and am waiting for them to come in. It appears that I have all the material to actually build the the "Seedling". Now to figure out the physical size of the different parts to make the x-y-z cart bot. Other than that jby bobt - Minnesota Twin Cities RepRap User Group
How about we don't make the stuff in the beginning to create the energy we need. 1. Take the ch4 (methane) convert it to carbon and hydrogen. Use the carbon to build things (carbon fiber and such) and use the hydrogen for energy source. 2. Use part of the hydrogen and burn it to create the above conversion process and use the excess heat to make steam for a turbine and make electric power.by bobt - Let's design something! (I've got an idea ...)
I only thought about Zach's suggestion of thread lock because the latest Harbor Freight Catalog showed up the other day. 1/4 inch Trim Router (item. 44914-2JR is on sale for $19.99 . And it appears that I just cannot pass this kind of deal up. I have finally figured out one rule for this. If the router goes MAJOR -(minus) Z axis movement DO NOT move the X or Y axis or you will cut your machiby bobt - Mechanics
I have just finished putting my RepStrap McWire frame together. That is the pipe part. Less see what it took to do it. 2 pipe wrenches (spanners) one in each hand then 1 hand for the pipe locking stuff and 1 hand for the magnetic angle meter to make it straight. HEY!! Wait a minute I haven't that many hands. So I went back and slowly put the connections together putting pipe locking stuff onby bobt - Mechanics