Talk:Prusa Mendel

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Thick Sheet

What specifically is the "Thick Sheet" mentioned several places? I'm assuming it's not egyptian cotton...? Could anyone in the know update this? --Jamesb 14:13, 19 March 2012 (UTC)

Answer: the material for your bed. MDF (medium density fibreboard) is a good example. Jkeegan 14:59, 19 March 2012 (UTC)

BOM

Is there a reason that the X smooth rods need to be 495mm long? On my build that is quite a bit longer than needed. --Bryan 10:33, 1 February 2011 (PST)

Yeah, I can confirm that 420mm is plenty long enough for the X on my build. --pelrun 20:45, 13 April 2011 (AEST)

Is the BOM primarily documented here or on github? We should not double document this and have the documentations inveitably fall out of synch. Either the git BOM should be deleted and replaced by a link to the wiki or vise versa, but having both can only lead to confusion IMHO. --TheOtherRob 16:13, 28 October 2010 (UTC)

The BOM is primarily documented here, until completed. Then it will move to the git. The picture was re-inserted to provide a link to the bigger version, this is not possible with the side-block, or do you know the way?. --Sikko 29 October 2010

Good point, I made the image clickable for all developments now.. not really sure why I didn't do that in the first place but it's fixed now. If the BOM is here can a placeholder be put in the github text linking to this location. That way people don't get confused by an out of date BOM at github. --TheOtherRob 18:09, 1 November 2010 (UTC)

Front-Rods.png shows a nut in between the y-motor bracket and the 608 bearing. However, in y-rods.png it is removed. I built up the whole frame before realizing my stepper shaft was too short to line up the gear and the bearing when the nut is there. Which version is correct? --Projoe 2010/01/24 11:36 EST

The y motor bracket got updated to a thinner version which requires the nut. The older version was thick enough to make the nut unnecessary. Sorry about that. --Kliment, 01. Feb, 2010

Z axis motors

Prusa has his motors running in parallel on the controller. This is causing me concerns especially if your motors require a fair bit of power. Since they are being ran in parallel, that doubles the current required and causes the motor drivers to run closer to their maximum current output. I was wondering if the coils were connected in series, would it run better since all that is require is a higher voltage and the normal power running to the drivers is 12 or more volts which would be fine running 5v motors. Series would also require as much current as a single motor so since the motor drivers work by restricting the current, it would give more torque since you can now put more wattage through the motors. (e.g. the motor driver has a maximum of 2 amps driving current and you have 2 motors that require 1.5 A at 5V. Since the supply powering the motors is 12v, instead of supplying 5v at 2 amps (which is maxing the driver and is less than the 3 amps required to run both motors) in parallel, have them in series driving them at 10 v at 1.5 amps.) -ZNahum

It makes the wiring significantly more complex, and slows down the axis (higher overvoltage = higher step rate). The Z axis doesn't need any more power, I've set the current limit on my stepper drivers fairly low, and it still moves extremely fast. Not everyone has 5V motors, and running the motors at an undervoltage is a much worse idea than running them at overvoltage. Feel free to try it in series, it will probably work fine if you have 5V motors, but I'd be against making that the default. --Kliment, 01. Feb, 2010

Accuracy

What level of accuracy can be expected from this printer? --Scramble 11:50, 23 June 2011 (UTC)

How are you measuring? If you want examples of things printed with it, here's a comparison with a commercial FDM machine:

[1]

And here are some examples of prints on a prusa with linear bearings:

[2]

That's helpful, but I was hoping for a resolution. --Scramble 14:09, 23 June 2011 (UTC)

Engrish ahoy!

This sentence needs a rewrite:

 Because of it's complexity, the Prusa Mendel can be living thing. I update it all the time. It's unique feature but it should be standard. We are living in feature, we don't care if it's a bit different every time; our printer will print it in same time

It reads like something from a chinese furniture assembly manual. Perhaps something like

 Due to its simplicity, the Prusa Mendel is a living thing. It is easy to print out not just replacement parts, but new ideas. It has many features that should be standard. We are living in the future(?) We don't care if parts are a little different, our printer will print just as well


Threaded Rod Cut Instructions

Is it worth mentioning that the remainder of the last piece can be used To make the frame jig J1?

BOM doesn't list electronics

The BOM doesn't say anything about buying electronics. Which set(s) of electronics work with this model? It seems like one of the requirements for building a Prusa Mendel. -- Creidieki 21:37, 12 August 2012 (UTC)

Price for BOM(sans electronics)

Getting most parts(every bolt, nut, washer, and threaded rod) from Fastenal, the smooth rods from McMaster, the motor from Makerbot, and the top plate from Home Depot, the overall cost for non-printed parts is 251.04(USD). YMMV, but I think with a fully assembled RAMPS kit or otherwise, people should plan to spend about (Correction!)$400-$500 or so. --firestorm713 5:41, 23 August 2012(UTC)