3DR Part Sourcing

Hi,

I've built two 3D printers from kits, and now I'd like to build a RichRap 3DR delta printer from scratch. My question is about sourcing of the smooth rods. I have two questions:

1. Do these need to be stainless steel or just steel (such as drill rods)?
2. Where is a good source for 6mm smooth rod?

It looks like the standard 3DR needs a total of 6 smooth rods, each 450mm long.

If I went with 400mm instead of 450mm, McMaster has steel rods at $10.38 each, while stainless steel is $25.53 each. I also found some drill rods on eBay that are 36" long and are $10 each.

Thanks,
-- John

The smooth rods don't need to be stainless. However, getting hardened rod (not cheap drill rod) is a good idea. Cheap drill rod will end up with grooves in it from the linear bearings, and tends not to be as tight of tolerance. It will still work though if you are on a real budget. The hardened rod from McMaster is a good choice (part number 6112K42 is what you're looking at?)

Thanks NewPerfection.

Now for my next question. I'm thinking of switching the rods from 6mm to 8mm for two reasons. First, I'm planning to use the parts from my Printrbot Simple to build the 3DR, and it has 8 LM8UU bearings in it, which means I wouldn't have to buy any bearings. Second, it seems like LM6UU bearings are hard to get here in the US at a reasonable cost. The 6mm bearings seem to be 5-10 times more expensive than the 8mm bearings. Is there a good source for LM6UU bearings in the US? Or should I just change the design to use 8mm rod?

You can get cheap ones from China that usually work pretty well. See: [www.ebay.com]

Or VXB has LM6UU's for less than $7 each: [www.vxb.com]

Going to 8mm rods and LM8UU's is another option, just make sure that you are able to modify everything to work, such as the carriages.

Thanks for the info. I thought long and hard about which way I wanted to go. In the end, I decided that, since I like to design things, I'd modify the appropriate parts to use 8mm rods. That way I can make maximum use of the vitamins from my Printerbot Simple. The "easiest" way for me to modify the parts was to draw them from scratch in Solidworks. Well, I couldn't leave well enough alone, so I modified the shape of the base:



I'll need to redesign the top pieces, and the carriages, but I should be able to use all the other pieces without change.

Edited 1 time(s). Last edit at 09/11/2013 12:11AM by JohnSL.

What are the profiles size? 15x15 or 20x20? 20x20 is far cheaper than 15x15 at least here in Europe. You can get 1m for only 4€ which is about 5 USD and they are widly available.

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Blogs:
Meine 3D Druck Abenteuer
[3dptb.blogspot.de]
FLSUN Delta Drucker für Deutschland
[flsun-deutschland.blogspot.com]
Books on 3D patents:
[goo.gl] (english)
[www.amazon.de] (deutsch)

They're designed for Misumi 20x20 extrusions, which were $4 each. The rods came out to about $10 each, so they're a much larger part of the cost than the aluminum extrusions. I order the rods and extrusions from Misumi.

Does anyone know where to get the anti-backlash springs he uses on the extruder arms?

Quote
caffeinatedsoap
Does anyone know where to get the anti-backlash springs he uses on the extruder arms?

Use rubberbands?

Quote
caffeinatedsoap
Does anyone know where to get the anti-backlash springs he uses on the extruder arms?

I bought mine at a local hardware store called Elliotts Hardware in Dallas, TX. The number was like 178 or something like that. Most hardware stores carry a bunch of different sizes, and you can easily compare the sizes to find the right dimension. It would be nice to know RichRaps exact source though as the springs i used may have been too tight or not tight enough.

As mentioned above, rubber bands work really well too. You may also find that you don't need them at all. I have one machine without any fitted and I can't really tell the difference. Maybe it will be required when the rod joints wear down, but that's not happened yet.

My test springs were from an old spring-kit sold here in the UK (Maplin) for a few £ the set.

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[richrap.blogspot.com]

Awesome thanks for the information folks!