Random Questions for building printer from scratch

• For the Y axis movement, is there a benefit to belts being place above the rails? Is it just easier to build? Could there be benefits to have them below the rails since the weight of the X axis is below? What about inside/outside?
• What about the positioning of the Z axis threads? Inside/outside/between rods?
• Would bead-blasted aluminum stick better/equal with painter's tape because of it's uneven surface texture?
• Ball bearings = no grease, right? Seemed to be the obvious answer to me, but there are a lot of things I have come across that show me just how close to nothing I know.
• Has anyone tried unique build plate covers for sticking prints like 2K clear coat/powder coating/etc?
• Are any of my ideas strange? I've gotten no feedback from a helpful community, so I know I'm doing something wrong. Be honest, it's the best policy.
• I'm purchasing a 300mm by 300mm heating pad for my 440mm by 880mm build plate. Sufficient? Need two? How would I wire two? [Megatronics V3]
• Does this post make my stupid look fat?

Edited 1 time(s). Last edit at 03/20/2014 07:59PM by MrDoctorDIV.

Uh... you are under the impression people here have answers.

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Does this post make my stupid look fat?

Not to me, it looks like you have ideas and want feedback on them.

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I'm purchasing a 300mm by 300mm heating pad for my 440mm by 880mm build plate. Sufficient? Need two? How would I wire two? [Megatronics V3]

In parallel, ie positives from both go to positive rail on heated bed supply (hope you got a phat power supply, that's over 400 watts draw) and negatives from both to negative (ground, zero volts) on the power supply.

You don't NEED 2, just it will heat up quicker when printing ABS style plastic, PLA style plastic is easier, does not need heated bed,

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Has anyone tried unique build plate covers for sticking prints like 2K clear coat/powder coating/etc?

Matt hair spray or PVA paint (plastic welding, for joining plastic) is pretty good.

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Ball bearings = no grease, right?

Hmmm... they usually work better with a bit of grease. Bearings on a RepRap work better / less friction than other solution.

Your other points, I have no firm opinion on, I doubt it makes that much difference.

Thanks for answering! Even just those few have been helpful.
What about the thermisters? Just one and hope it heats up evenly? Same pad would mean that they stay pretty much the same, right?
And yes, I am using an 850W PSU.
Is there anywhere else I can go to ask difficult questions or am I going to have to be one of those people that finds out and tells others?

What printer are you trying to build?

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Waitaki 3D Printer

My own design. I don't even know what the basis of Prusa/Mendel and others even are. I've just looked up random built 3D printers, home and production, and used my mechanical niche to decide for myself what's best since not much is proven science. People built H-bots, I assume just to do it because I find an H-bot to be against sense in 3D printing quality and accuracy. So I've had to engineer most of my own ideas. I can say it is largely based on my Solidoodle, though. I have personal experience with that and it's ups and downs.

For the heatbed, I custom ordered a silicone heater.. a 230mmx300mm (thats my build platform.. its on the 120Vac rail. they dont cost much.. I think I paid under 100$ for 2 of them.. best of all, you dont need a big power supply becase they are on the 120v.. so, you need about 6A for a single extruder with motors. 10A for a double extruding system.

a simple SSR (solid state relay) will do the trick to turn on and off the heater. and best of all, it come with a built in thermistor (NTC 100k) and 3M sticking pad so you can stick it under the glass.

You can custom size it, ask for the Watts and voltage you need.. mine are 500W/110V so its about 5W/inch² the average PCB heater is arount 2W/inch².

just my 2¢ ;-)

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Rigor_M
For the heatbed, I custom ordered a silicone heater.. a 230mmx300mm (thats my build platform.. its on the 120Vac rail. they dont cost much.. I think I paid under 100$ for 2 of them.. best of all, you dont need a big power supply becase they are on the 120v.. so, you need about 6A for a single extruder with motors. 10A for a double extruding system.

a simple SSR (solid state relay) will do the trick to turn on and off the heater. and best of all, it come with a built in thermistor (NTC 100k) and 3M sticking pad so you can stick it under the glass.

You can custom size it, ask for the Watts and voltage you need.. mine are 500W/110V so its about 5W/inch² the average PCB heater is arount 2W/inch².

just my 2¢ ;-)

Can you let us know your source for these silicone heaters!! Your pricing sounds very low compared to what I've found - and that doesn't even include an embedded thermistor! Thanks !

Edited 1 time(s). Last edit at 04/03/2014 05:26PM by mobile chernobyl.

Sure, i'm glad to help the guy with some word to mouth ;-)

Keenovo on ebay

Just send him a email with the specs.. he also have standard sizes already to buy from.

It takes 7 open days to build the custom heater and send time (took 1 week ½) from China to Est Canada. ( Very fast for free economy shipping)