Prusa i3 Rework Parts: What am I missing?

I know I missed something. I always do. I'd rather find out now and be able to order it than pause the build while I'm waiting for that one part to come in.

Here's what I've bought so far:

Rework Melamine Frame- Includes the vertical frame, rear supports and the print bed frame.

Printed Parts Kit

Rod Kit
X Axis;
2x 350mm 8mm smooth rod
Y Axis:
2x 370mm 8mm smooth rod
2x 380mm M10 threaded rod
3x 210mm M10 threaded rods
1x 340mm M10 threaded rods
Z Axis:
2x 320mm 8mm smooth rod
2x 300mm M5 threaded rod

Bearing Kit
11 x LM8UU linear bearings
1 x 624zz bearing
4 x 608zz bearings

Fastener Kit
41 m3 x 14 shcs
7 m3 x 30 shcs
2 m3 x 60 shcs
6 m4 x 20 shcs
1 m8 x 30 shcs
1 m8 x 20 set screw
53 m3 washer
6 m8 washer
34 m10 washer
5 m3 x 8 set screw
33 m3 nut
6 m4 nut
2 m5 nut
1 m8 nut
34 m10 nut
1 m8 nyloc nut

Hobbed Bolt

2 x extruder idler springs

5x NEMA17 steppers (bipolar, 1.8deg, 1.2A, 0.4 N.m)

2x 5mm x 5mm couplers

2x Timing Belt Tensioner Springs

2x 18 Tooth GT2 Pulley

760mm GT2 Belt

900mm GT2 Belt

8x Bed springs

2x 100K Thermistors

40mm Cooling fan

J-Head hotend

AT2560

Ramps 1.4

4x A4988 Stepper Drivers

4x Stepper Driver heatsinks

MK2 Heatbed

3x Mech end stops

12V 20A 240W Power Supply

50mm x 100ft Kapton tape

Glass bed

1kg 1.75mm PLA

I'm 99% sure I've got all the necessary tools, but if not I can just run out and buy them locally.

Thank you for looking!

I just started assembly on that same configuration. Rework parts with the melamine supported frame. Here's my spreadsheet, if it may be of some help to you to compare:

Rework BOM

I'm done with most mechanical assembly, including the extruder, but still need to attach motors and electronics. So while I'm not very experienced, my experience is quite fresh and at a glance, your list looks right to me. I've got 20-teeth pulleys, but I have no idea if that matters.

My major issue was not understanding how the y-axis attached to the supported frame, so I planned for 4x210mm threaded rods. Fortunately, I cut them myself from meter rods and had enough leftover to make a ~340mm like you have there. Then I did have to go find additional m10 nuts and washers.

Generally though it looks like I will probably have a random assortment of parts left over.

Building has been fun so far -- good luck!

Hmmm. Based off your spreadsheet it looks like I'm good. I need to pick up some Loctite and a new metric drill bit set, but I've got 2 Home Depots, a Lowes, and a Harbor Freight within 15 minutes of my house so no worries there.

Thank you!

The metric bits may not be all that necessary. Most of the parts fit fine and some just needed a little bit of cleanup that could have been done with a close-sized standard bit.

Oh, and check if you have hardware for the frame assembly. I did not, but got 6 each #6-32 1-inch screws and nyloc nuts from Home Depot that worked fine.

Edited 1 time(s). Last edit at 06/04/2014 04:09PM by kellymc.

I should be good on hardware. Got the Hardware, Frame, Bearings, Printed Parts, and a few other things in a single package from an eBay seller for a good price. As long as I didn't miss anything major the whole build's coming in at around $420.

And another thing you might have seen on my thread here -- The Rework assembly instructions have the Y motor and endstop in the front. I did it that way and have it all Loctited down, but I don't know understand why they did it like that. You've got to run wires out to the front and it seems like it puts more bulk and fragile parts right out where you'll be taking prints off. I'd switch the idler and motor mount positions if I still could.

I'll take a look at it during the build. I'm not confident enough to change anything, but if it's easy...

Quote
SimianSteam
I know I missed something. I always do. I'd rather find out now and be able to order it than pause the build while I'm waiting for that one part to come in.

Here's what I've bought so far:

Rework Melamine Frame- Includes the vertical frame, rear supports and the print bed frame.

....

Would you mind sharing your BOM sources? I'm about to start ordering my kit, one of the things I'm hung up on is the hobbed bolt. The distance from the bottom of the head to the hob seems unclear as to what it should be.

Something I came across when building my Rework. 14mm m3 screws are too long to attach stepper motors to printed motor mounts! 12mm are perfect size. In fact a lot of 14mm m3 screws can be replaced by 12mm screws with better results (for example attaching z mounts to vertical metal plate).
I also assembled printer with Y motor in front following instructions, but I don't see why it can't be in the back. So I moved it to the back and also flipped motor to the right side of the moutning bracket (see pic). But follow my advise at your own risk, I didn't get my printer working just yet

Quote
pumm3l

Quote
SimianSteam
I know I missed something. I always do. I'd rather find out now and be able to order it than pause the build while I'm waiting for that one part to come in.

Here's what I've bought so far:

Rework Melamine Frame- Includes the vertical frame, rear supports and the print bed frame.

....

Would you mind sharing your BOM sources? I'm about to start ordering my kit, one of the things I'm hung up on is the hobbed bolt. The distance from the bottom of the head to the hob seems unclear as to what it should be.

Sure!

Followed the BOM at [reprap.org]

Got the frame, bearings, hardware, rods, etc from an eBay seller: [www.ebay.com]

12v 20A Power Supply came from eBay as well.

Pretty much everything else except for the glass (eBay) came from [www.robotdigg.com]. They're in China, but shipping was reasonable. Total cost for all this:

Product
NEMA17 Stepper Motor 40mm Long, 1.2A
Flexible Coupling 5mm Shaft to 5mm Screw
Timing Belt Tensioner Spring
760mm 380 Teeth Closed-loop 6mm Width GT2 Belt
18 Tooth 5mm Bore GT2 Pulley
Compression Spring for Heatbed and Extruder
12VDC 4CM Cooling Fan
100K Glass-sealed Thermistor
J-Head Hotend
Arduino Mega 2560 R3
Ramps 1.4 Board
A4988 stepper driver
MK2B Heatbed
Microswitch Board w/ Lead Wires for 3D Printers

Came to about $200, shipped. I probably could've gotten a few things cheaper, but in the end it was more practical to order the bulk from them.

Quote
Bratan
Something I came across when building my Rework. 14mm m3 screws are too long to attach stepper motors to printed motor mounts! 12mm are perfect size. In fact a lot of 14mm m3 screws can be replaced by 12mm screws with better results (for example attaching z mounts to vertical metal plate).
I also assembled printer with Y motor in front following instructions, but I don't see why it can't be in the back. So I moved it to the back and also flipped motor to the right side of the moutning bracket (see pic). But follow my advise at your own risk, I didn't get my printer working just yet

Thanks! I'll keep an eye out for the screws. I'm probably going to follow the build instructions to the letter this time around since it's my first build and I don't feel comfortable experimenting yet.

Thanks for sharing, when you quoted your price I was just curious where you got everything from. My build is around $500 so far which from what I can see is related to the fact that I'm sourcing my parts from USA sellers so I don't have to wait weeks to get stuff (also to avoid headaches if there's problems with the parts). There's a few parts I decided to spend alittle more on to make sure they were more reliable. I'm also going with an aluminum frame which is a nice chunk of the difference. I also used kellymc's bom spreadsheet to compare against and was able to find a few savings doing that, thanks for sharing yours as well.

Some of the parts I decided to spend a little more on included:

Arduino Mega 2560 R3 (I can get a genuine board for $35, I saw that some ppl had issues with the clones so the cost difference seemed worth it.
The J-Head Hot end, from what I read the chinese knock offs are more prone to problems so I spent the extra getting it from a more reliable source.

Yes, RobotDigg is in China, but I got my stuff less than a week after I ordered it.

Oh, and they sent me a custom length drive belt free.

Have you started your build yet? I'm still waiting on motors, but I've got my extruder assembled and have put all the electronic boards together and have been thinking about how the wires will run. I'm curious how others are doing with their first Rework builds.

Concerning flipping the y motor around. I would say go ahead and assemble your frame the same time you loose fit the y-axis together and you can test fit them and see how it goes together. I think you'll see what I mean and if you're comfortable with it, it would be pretty easy to switch the 340 mm rod to the other end before you have it all tightened down.

Loctite be damned, I'm going to switch mine this weekend.

The other modification I'm considering is forgetting the X endstop mount, which is on the opposite side of the frame from the RAMPS. I've seen others that just zip tie that one to the X smooth rods, which I think would work fine until I decide if I want to print a better holder for it on the RAMPS side.

Hey, I figured something else out last night while switching my Y-axis ends.

On the print bed base, don't zip tie the bearing on the single-bearing side at first. Just put the bearing on the rod and let the bearing nestle into the slot. Later, when you're tightening everything down, you can nudge your transverse axes in or out until the bearing rests squarely in the slot when slid to both ends. That will tell you when you have the width just right.

That probably doesn't make any sense at all if you haven't gotten there yet. But the instructions tell you to measure 186 mm between the outsides of the printed corners, but there's lots of variation on the parts because of rough printing, so it's hard to measure accurately.

New question. I've got custom length belts too, but It appears my custom lengths were wrong.

Should custom belts just run from pulley to idler with one pass through the holder/carriage, or is tightening/doubling of some sort still necessary?

My belts are too long to go straight on. I certainly could just cut them and tighten with zip ties, but I want to make sure I'm not wasting the benefit of having custom length if I'm wrong.

Thanks.

I went ahead and cut them. I think it's easier to adjust them that way anyway, especially if you already installed the idlers.