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(RepRap Användargrupp)
Re: Lead Screw usage for X and Y axes - 10 years ago
Looking good! How thick are the lead screws? And do you use anti-backlash nuts? I noticed you use only one smooth rod, so you're relying on straightness of the lead screw.by tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
We're spoiled But shouldn't a few cleverly coupled components like coils, capacitors and a resistors be able to give a normal a4988 the slight phase shift it needs, just around the resonant frequencies? I would expect the total cost of the needed component to be < $10. Manually adjusting a potentiometer to adjust a filter to hit the right frequency bandwidth for my setup would be a low addiby tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
Quotedeaconfrost As it is the printer tops out at around 25mm/s to 30mm/s I don't think it go any faster with 1 start. Is it mid-band resonance that limits the speed? (would look like these videos: [1], [2], [3]). BTW, found a video showing anti-resonant drivers + rotating the nut: [4] The cheapest anti-resonance stepper drivers I've found are $40 each [5]. This makes cheap leadscrew + anti-resby tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
Quotedeaconfrost I made the i3 leadscrew upgrade with PLA, since the z axis has much less movement I was too worry about the pla melt away or eaten by the leadscrew. Did you use PLA for the Z-nut? Cool! That saves a machined part and maybe even some money At what speed does the XY axes of the big printer top out? 30 mm/s or faster? How long is the travel per revolution on the big printers XYby tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
Using only single starts is super interesting as an experiment! I really wonder just how slow the printer gets and how pushable that limit is. Even if multi-start is clearly the way to go, I think arranging extreme cases like this can speed up learning alot. Looking forward to your reports about it. Nice looking printer by the way. Judging by the amount of orange parts, it looks like you're alreby tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
QuoteMKSA May be I have missed something but nowhere can I see any valid justification for the use of ball lead screws on these machines ! I don't know where you've looked or what you find to be valid, but here's a random selection of reasons for lead screw- and ball screw usage on RepRaps Less ringing Lower unique part count The learning experience The availability of aggressively threaded roby tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
Thanks for the designworld link, very interesting reading!by tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
Hi, Thanks! I came across something puzzling today, ball screws with anti backlash nuts and machined ends for $28 each... See Robotdigg I've never seen ball screws this cheap, does anyone have experience with them? Looks like I'll be building, testing and comparing linear actuators around March 8 btwby tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
Hello, welcome to the thread! $10 per meter, wow that's cheap. If you rotate the lead screw instead of the lead screw, you get the chance to gear up rotations per mm. See for example this youtube video. Rotating the nut also allows using larger diameter lead screws, who generally have more mm per revolution. I'm seeing you'll only receive standard bronze nuts. Are you going to compensate for wby tobben - Mechanics
Re: Idea: A RepRap Hanging From the Ceiling - 10 years ago
First version of assembly manual published today! Clerck Assembly Manual v0. Comments, improvements and builds welcome!by tobben - Delta Machines
Re: Lead Screw usage for X and Y axes - 10 years ago
Just got a $76 quote for XCF10-12x2.5M anti-backlash nuts, with a minimum order of $500, confirming the price from Kyo-89's sourcing research.by tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
Sorry for the radio silence guys, I'm getting back into lead screw sourcing today. Quotenophead For quick movement with longevity you need multi-start high lead ball screws and that is not compatible with low cost. Some rough numbers on life time and cost: M̲a̲n̲u̲f̲a̲c̲t̲u̲r̲e̲r̲ ̲a̲n̲d̲ ̲s̲i̲z̲e̲ ̲|̲ ̲$̲P̲r̲i̲c̲e̲ ̲f̲o̲r̲ ̲1̲ ̲m̲ ̲+̲ ̲2̲ ̲f̲l̲a̲n̲g̲e̲d̲ ̲n̲u̲t̲s̲ ̲e̲x̲c̲l̲ ̲V̲A̲T̲ ̲|̲ ̲L̲i̲fby tobben - Mechanics
Re: Idea: A RepRap Hanging From the Ceiling - 10 years ago
Hm... I think the Smoothieboard version of Clerck would be best developed by someone "scratching his own itch" (someone who really wants a Clerck with Smoothie and understands the Smoothie benefits well). That's not me, so I won't do a physical build with Smoothie myself. The moment you decide to do a Clerck+Smoothie build, send be the board, and I'll help you as much as I can. Since you have thby tobben - Delta Machines
Re: Idea: A RepRap Hanging From the Ceiling - 10 years ago
I have no ARM plans myself right now. If you would like to develop it with me I'd be happy to co-develop using your fixable Smoothieboard =)by tobben - Delta Machines
Re: Kit for one day build workshop - 10 years ago
Thanks for the input! You're really right that participants needs to be prepared for and enthusiastic about tinkering, building and learning. I understand you've had bad experiences with printed parts. My own experience is that printed parts work really well. Other than frame stiffness, do you see any advantages of the Makerbot clone over for example a Prusa i3 kit? The Cloner looks like a gooby tobben - General
Kit for one day build workshop - 10 years ago
Hello Everyone! I'm working on designing a one day RepRap build workshop. The idea is similar to what thetazzbot presented here. We're especially interested in realizing what he mentions at the end of the request: Quotethetazzbot It would be neat to establish a framework for experienced builders to use as a guideline to conducting these kind of classes in their local markets. Our project will cby tobben - General
Re: Lead Screw usage for X and Y axes - 10 years ago
Thanks for the links. The pcblinear one led me to read about the Aluminatus. Do you know anyone who have used one of these printers for a while? It would give us more exact knowledge about the wear problems. Emailed Vermont Rapid Prototyping about it. Quotecozmicray Probably too expensive for your application Do you know how expensive? A bit cheaper than ball screw would be nice.by tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
I expected it to be optics, but it could have been just a curved figure. Cool microscope solution. I just zoomed in the picture and drew the graph by hand in Inkscape, nothing rigorous.by tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
How bad is the lead screw longevity issue? I still wonder if we could get good enough (2500 hrs?) lead screw lives by minimizing mass and acceleration and doing some research on lubrication, number of starts, lead pitch, diameter, nut length, nut/screw material combinations. Equally well would be to find a source of cheap ball screws+nuts or a feasible way to produce them ourselves. The possibiby tobben - Mechanics
Re: Lead Screw usage on X and Y axes - 10 years ago
I guess I'm not in a position to answer this yet, but the successful builds linked in the first post shows some interesting properties: Very little ringing/underdamped oscillation/shadow wave patterns near corners. Clean and simple mechaincs Simple assembly? Durable? Low maintenance? Possibility of a lower unique part count? The possibility of a straightforward modular design based on linear acby tobben - Mechanics
Re: Digipot board for RAMPS + DRV8825 : Looking for helping eyes - 10 years ago
Nice work! What's the status on this development? I'm currently looking for a complete electronics set with digital potentiometers (or any other way to get away from manual Vref adjustment) and higher current output than the A4988 can give (preferably drv8825)... If this board is known to work well, I might just put an order for it on OSH Park (fiddling with Marlin source is ok, as long as I knby tobben - Controllers
Re: Lead Screw usage for X and Y axes - 10 years ago
Quotealbatroopa Here's a render of what i have so far Render and here's the bill of materials: BoM Was just looking through your BOM and noticed that the planned lead screws use imperial units. Are you sure that won't be an issue? I changed my imperial-unit Z-threaded rods on my first Printerbot+ because the millimeter/inch roundoff errors produced visible artifacts (every fifth layer was notiby tobben - Mechanics
Re: Lead Screw usage on X and Y axes - 10 years ago
Quotethe_digital_dentist You won't know how much torque you need until you know all the moving masses (rotational and linear) and the losses such as stiction and friction. The notion of stiction was new to me. It should be quite straightforward to test stiction for some different leadscrew/nut/lubricant combinations like this: Wind a cord around the center of the flanged nut Mount the lead screby tobben - Mechanics
Re: Lead Screw usage on X and Y axes - 10 years ago
Hm... You really know the trade offs between Nema 17 and Nema 23, dc42. I think I understand most of it. Short Nema 17 is what we want then. QuoteUsing leadscrews, you are likely to need less torque but more speed than for a belt-driven X or Y axis, ... Nice! With no experience of lead screws from before, I was expecting the opposite.by tobben - Mechanics
Re: Lead Screw usage for X and Y axes - 10 years ago
Thanks alby, you bet it does! So much concrete insight. I'll bake it into the wiki tomorrow. QuoteI can keep you updated if you'd like. Yes, that would be really interestingby tobben - Mechanics
Re: Lead Screw usage on X and Y axes - 10 years ago
Quoteuse ... motors with low inertia (short ones) Wow, that's a solution I hadn't thought of. So a short NEMA23 is better than a longer NEMA17 assuming all other specs equal. How great is this effect? Just making up an example: How much acceleration would a 42mm NEMA23 gain compared to a 60mm NEMA17 just from being short (depends on lead screw of course, say 10 mm per rev or something)? QuoteIby tobben - Mechanics
Lead Screw usage for X and Y axes - 10 years ago
Hello Everyone! I'm designing an all-lead screw printer (see here), and that's what got me started on this topic. The RepRap wiki page doesn't really adress X/Y lead screw usage, so I thought it should be filled in. Here are some of the questions I personally would like answered on such a page, but there's plenty of other interesting engineering questions related to quick lead screw moment. - Hoby tobben - Mechanics
Re: Large-scale 3d printer - 10 years ago
You don't have to build a frame if you don't want to: Clerck the hanging RepRapby tobben - General