Help with first time build

Hi i'm building my first C Bot, and wanted to know how do i know the length of the profiles needed,

i'm using 20*20 T slot and have a dual extruder, build volume +- 200*200*200

Hi, there is no defined length, also there is no official one 'true' CoreXY printer. Zelogik and Jand have made their designs opensource and you can find many more on thingiverse/physible sites, but the great thing about CoreXY is that they can be made as big as you want

I have a 360x360x360 frame and my internal print area is 230x190x180 because of the fact that I wanted all my parts to fit in the 360x360 square seen form the top. My X-carriage and belt system are on top of the machine so I could get more Z-height, but ended up making it into a laser cutter, so the Z-height isn't that important.

I would recommend you to either pick an existing design and look up the BOM yourself. As with all designs, if desired you can simply scale up the frame and smooth rods and the machine will still work! Keep in mind that larger distances require thicker smooth rods/rails unless you use a special extrusion with V-slot that functions as frame and as linear guide.

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http://www.marinusdebeer.nl/

I aggree, but when you enlarge a machine, it's not only a question of guides (smooth rods or whatever). Especialy with a machine supposed to print 0.1mm layers ! The structure must be stiff enough on the lenght and the printing surface must stay as flat on a larger surface. The same gap or missalignement becomes harder to manage as as the size of the machine increase. It's not linear but exponential. Imagine a supported 20x20mm aluminium frame bends of 0.03mm on 200mm long. Maybe the same profile 400mm long will bend 0.1mm. It's the same for the printing surface, with negligeable twist, cups and hills on a 200x200 surface, became realy problematic when size grows. That affects electronics too, because the weight of a 400x400mm surface is not the double of a 200x200mm but x4 so you'll need a more powerful motor and much more power. A 200x200mm heatbed needs 10 A, what about a 400x400mm ? A 30A power supply is not in the same price range than a 60A. What you need to keep in mind, is that increasing dimensions multiplies exponentialy the cost, throught structure, materials and components. Or your machine won't be as good/precise as her small sister.

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Collective intelligence emerges when a group of people work together effectively. Prusa i3 Folger (A lot of the parts are wrong, boring !)

That's why I believe a 120 VAC heated bed is the way to go for larger printers. For a 400 mm x 400 mm bed I'm using 120 VAC heat tape controlled by a solid state relay from the RAMPS board. AC can be scary but it saves having an extra power supply.

Sorry, slow computer double posted.

Edited 1 time(s). Last edit at 01/23/2015 05:03PM by runninfarmer.