First Build Parts Help - Prusa Mendel

Hi,

I'm trying to plan out all the parts I'm going to need for my Prusa build, but as it's my first 3d printer build, I need some input on the parts I'm going use. I'm trying to keep the build cheap which is quite difficult when delivering to Ireland.

Parts List:

Printed Parts: ebay.ie
Motors: aliexpress.com
Electronics: DIY Gen7 board with drivers from ebay.ie
Power: Spare PC supplies
Build area: Scrap glass and wood/aluminium
Belts: ebay.ie
I'm unsure about how much belt I need, the wiki says I'll need 840mm+1380mm, however others say a 2m length is enough for a Prusa?
Hot End: I orignally was going to go with a premade model from here: ebay.ie However, I do want to print with ABS and this insulator is PTFE, which the wiki says is no good :/
Can anyone recommend a cheap hotend which isn't too hard to put together? (the hot end is the only thing I have some hesitation about DIYing)
The end hot end from makergear looks quite good, has anyone had experience with it?

As fair as fasteners go, they will be got locally, but I can get 5/16" steel smooth rods for about the a third of the price as 8mm steel smooth rods, considering 5/16" is ~7.94mm, so should I get them instead?

Later I might think about a heat plate.

Thanks

Printed Parts: Those look good. Scratch that. Those look like Prusa iteration 1 parts. There are known issues with those that will give you problems. Look for sets of the newer version, i2.

Motors: Those look good.

Electronics: Gen7 is a good solution. The seller of those stepper drivers is very reputable.

Power: If you are not running a heated bed, you need ~6A on the 12V rail. With heated bed, at least 16A.

Build Area: That will work fine. Aluminum is easier to work with as it does not warp.

Belts: 2 meters of belt is enough for a Prusa with some left over.

Hotend: Makergear makes excellent hotends. The J-Head from hotends.com is excellent too. I have used both and have nothing but good things to say. I would not recommend the one you listed, PTFE is terrible used structurally under heat.

Fasteners: If you are only ever going to use the provided PLA bushings or other 5/16" bushings, then 5/16" smooth rod is fine. Just be aware that it will not work with LM8UU linear bearings.

Edited 1 time(s). Last edit at 08/12/2012 04:19AM by NewPerfection.

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Hello,

I would recomend 8 mm stainless steel rods and use LM8UU linear bearings!
Also don't use T5 belts becaus these have a lot of backlash! Use GT2 round profile belts!

If you have some questions let me know!

Charlie

CharlieSteurbaut Wrote:
-------------------------------------------------------
> Hello,
>
> I would recomend 8 mm stainless steel rods and use
> LM8UU linear bearings!
> Also don't use T5 belts becaus these have a lot of
> backlash! Use GT2 round profile belts!
>
> If you have some questions let me know!
>
> Charlie

With the proper pulleys, i.e. not the metal Chinese ones on eBay, T5 will have very little backlash. More than GT2, but probably not enough to be noticeable. That said, I too would recommend GT2 or HTD belts.

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Thanks for the replies

I'll try and find a set of iteration 2 parts then.
I'm looking at getting a new PC power supply as none of the ones I have here are new and they would don't have enough amperage on the 12v line.
The J-head from hotends.com is currently out of stock, I may get the makergear one, it looks pretty good.

I'm going to go look around for gt2 or htd belts, I'll post back with the ones I find.
Also, would I need different pulleys for those belts, or would the normal Prusa printed ones do?

I think I'll go with 8mm rods, and I might get LM8UU's.

For starting out what nozzle size should I use? And should I use 3mm filament too?

-Richard

I would recommend 3mm filament, but some others like 1.75mm. It's personal preference really. It's probably easiest to stick with 3mm.

For nozzle size, it's probably easiest to start with a 0.5mm nozzle. Brian is putting 5 J-Heads in stock each day, so you can always check back there too.

You will need different pulleys since the belt profile is different. Molded plastic pulleys with metal inserts work just fine, and you should be able to find them for $5 to $10 each at most.

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How many pulleys would I need to buy if I switched to gt2/htd belt? Just 2?

I've decided to settle on the hotends.com j-head with 3mm filament, makergear's shipping to Ireland is too expensive.

Thanks for your help
-Richard

Only two pulleys are needed. And instead of using one 608 bearing with two fender washers for the idlers, use two 608s next to each other, then you don't need the fender washers at all as the belt will stay centered. This eliminates the chance of the belt binding between the bearing and fender washer too.

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That hotend you found on eBay is the exact same one I bought and used for my first build. It's excellent, no problems so far and easily extrudes ABS without issue.

Thanks for the advice Cameron, I'm going to try and find some gt2 or htd belts with a sane delivery price.

Lodorenos, that's good to know, I'm going to wait, I won't be putting this thing together for another month or so anyway.

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-Richard

[tynan.me]