Assembly advice for rev. 4?

[Nicolinux 288]

Hi,

I am about to receive my kit (currently ddosing the dhl shippment site) and wondered if there are any important things to note for the assembly. I have read the instructions in the wiki and many posts here in the forums. It is hard to figure out if the posts are relevant here - other than looking at the post date and guessing about the used revision.

Thanks,

Stefan

[illuminarti 18]

I haven't studied the instructions in detail in over a year, but when I used them to put mine together, they were pretty good. The machine is really not that complicated mechanically - if you think about what's going on, and pay attention to the basics like getting things the right way round (the sides of the critical bits like frame and head are all labelled), then it will go fine.

The changes between the various revisions are fairly minor - particularly in the latest one, I think - so most anything less than maybe a year old is probably relevant. But off the top of my head I can't think of any assembly-related issues that have been posted on here that didn't come down to things not being put together right.

If you're not sure, just ask. We're a friendly bunch. :-)

 

[Nicolinux 288]

Thanks Simon. I was concerned about the extruder/hotend combo because I have read about many issues with clogging and the bowden tube slipping. But I am sure everything will be fine and the print quality way better than our Prusa Mendel i2...

Right now it is just my impatience. The UM crew did a great job. I ordered three days ago and the kit is at 60% shipping progress.

[nick-foley 5]

Ditch the stupid M3 machine screws used for installing the limit switches and use #4 x 0.5" Pan head, torx drive plastite screws instead: http://www.mcmaster.com/#99512a219/=nt3cr5

They are faster, easier, and much stronger + more reliable long term.

The current screws are a very dumb use of a machine screw (and they are tapping the switches even, good lord that's a lot of unnecessary work, for such a terrible result!) and it is inevitable that you will strip some of the switches either during assembly or later when you're adjusting them.

It is not fun to have a machine whose limit switches you can not trust.

 

[valcrow 144]

I agree with Nick, those limit switches are frustrating. I've stripped 7 of the 12 holes on the limiit switches. Luckily each switch had 1 stirpped hole which still keeps it in place for the most part with 1 tightish screw. One of the switches I had to fill with epoxy since it had both threads stripped. Be very gentle or heed nicks advice. And being gentle might not work.

For all the great components that come with the UM, the limit switches and the fans are really shoddy quality.

My other piece of advice for assembly is.. Tighten this pully down with the new setscrews they give you A LOT once you have all the belts roughly in place. You don't need to tighten the other pullys just yet before you start working on the print head. But the ones immediately attached to the short belt and motors. tighten down lots. It'll be hard later and will cause skewed prints if you it loosens itself.

Otherwise everything else should go pretty smoothly. Read the wiki comments on the page before starting that page. They warn you of common troubles.

 

[Nicolinux 288]

@Nick: Thanks for the suggestion. I'd like to switch to the torx screws. I need to find out how they are named here in Germany.

@Valcrow: Cool, I have read your post a that was one of the few things I actually wrote down because it seemed important. Thanks again.

 

[nick-foley 5]

 

My other piece of advice for assembly is.. Tighten this pully down with the new setscrews they give you A LOT once you have all the belts roughly in place. You don't need to tighten the other pullys just yet before you start working on the print head. But the ones immediately attached to the short belt and motors. tighten down lots. It'll be hard later and will cause skewed prints if you it loosens itself.

 

YES. Good point. I spent several days trying to debug this problem when I built my first machine. I thought I had everything tight, but once the machine is assembled, you just don't have enough clearance to get those pulleys as tight as they need to be.

Really, when it comes down to it, this is another case of the wrong part being spec'd with the stock Ultimaker. A more effective solution is this: http://www.mcmaster.com/#catalog/119/3052/=nto4lp

Which is a slightly longer, cone-point set screw of the same size. The extra length (not really extra, but correct, as it just fills the tapped hole of the pulley) allows you to properly tighten things without worrying about stripping threads, and the cone point is much more effective at setting into the hard steel of the axis rods.

 

[Daid 303]

Next to that pulley, I would also tighten the pulleys on the motors with as much force possible. If those get lose you'll have to take out the motor to tighten them properly.

(Note, I can tighten that back pulley, it requires a downwards angle next to the Z guide rods for your screw driver. It's a tight space and I have small hands. And I've done it on enough machines to get some skill in it)

As for the set-screws, the kit comes with some spare in case the supplier added some bad ones in the batch once again.

Else you can also get those from http://www.rvspaleis.nl/ in Europe.

[Nicolinux 288]

Thanks guys. I will keep this in mind. For the screws I asked in the german subforum where I can get them around here. I have a bad feeling ordering stuff from a shop where I don't understand the language

Now it is up to DHL the shippment status hasn't changed since saturday... (I guess they need more ddosing of the shippment tracking site

 

[joergen 2]

Ditch the stupid M3 machine screws used for installing the limit switches and use #4 x 0.5" Pan head, torx drive plastite screws instead: http://www.mcmaster.com/#99512a219/=nt3cr5

They are faster, easier, and much stronger + more reliable long term.

The current screws are a very dumb use of a machine screw (and they are tapping the switches even, good lord that's a lot of unnecessary work, for such a terrible result!) and it is inevitable that you will strip some of the switches either during assembly or later when you're adjusting them.

It is not fun to have a machine whose limit switches you can not trust.

 

The M3 screws work fine on the end switches, no need to raise panic... plastite screws are not easy to find in the EU, and M3 does the job just fine as long as you don't over-tighten them and strip the plastic. if it really fails, use locktite, or use a longer screw and a M3 nut.

yes, plastite screws will give you a much better grip, after all that's what they are engineered for. are the M3 good enough for this purpose, after 3 years of product development, and hundreds, if not thousands of users worldwide? yes. no need to panic.