Rep 1 warped arms

[Chris Fastie]

I have to decide what to do about the warped z arms on a Replicator 1 with 650 hours. Most of those hours were printing PLA with the build plate at 45°C, and only 20 hours were ABS at 110°C with a temporary enclosure. The build plate is very flat and I can level it fine so there is no problem printing parts that span the entire plate. So the printer still works great. But...

Questions:

• Will this get worse, or do the arms stabilize? 
  
• Is it too late to benefit from arm stiffeners, if they will even fit now?
  
• Can I heat up the arms and bend them straight again so the arm stiffeners fit?
  
• Do those arm stiffeners prevent the warping from happening in the first place?
  
• Does the warping happen with the build plate at 45°C, or did it happen in the 20 hours of printing ABS at 110°C?
• Why do the arms warp upwards?
• Should I spend $150 on aluminum arms or save it for a new printer?

The end of the right arm is a couple of mm higher than the left arm.

The right arm is warped upwards more than the left arm.

The left arm is warped just a little.

Thanks,

Chris

[delsydsoftware]

I would personally spend the $150 on Bottlework's aluminum arms if you afford it. It really improves the whole print experience with the Replicator 1. I think I've only had to re-level my build platform a couple times since Feb 2013. And, print layer quality goes up quite a bit when the HBP arms stop gently flexing. My HBP arms had a similar amount of bend to them, and you could see the arms moving during some fast prints.  When you actually take the build platform apart and relieve pressure on the arms, they will bend even further out of place.

After switching to a glass build plate and installing Bottlework's arms, I'm hard-pressed to find a printer with better output quality.

[Ryan Carlyle]

I would say you'll have trouble installing stiffeners now. It's possible they will actually cause the bushings to bind on the rods. I saw some of that on my R2x before I got the BW arms.

The rods actually warp because repeated thermal cycling causes the internal stress from injection molding to "shake out" and shift the shape to a lower-stress conformation. (That's why they can warp upwards.) You don't need to actually go all that high temp for this to happen. Just repeated temp cycling can do it.

As for whether it's better to save up for a new printer -- have you fixed your Rep1's electrical problems yet? All stock Rep1s are ticking time bombs for 5v regulator failure frying half the Mightyboard.

[Chris Fastie]

Well I guess I can afford $150 -- that's just four rolls of PLA. On the other hand, I could print a lot of useful parts with four rolls of PLA. 

Ryan, thanks for explaining how the arms can bend upwards, and do so even when using lower temperature. Your explanation suggests that much of the stress might have been relieved from my arms, so maybe they won't deform much more? I could live with that.

Yes, I have replaced the regulator, and both filament feed mechanisms, and the x-axis cable. But those upgrades cost almost nothing (thanks in part to Makerbot support). And $150 is not nothing, darn it.

Thanks, 

Chris

[Ryan Carlyle]

Downside to the "wait and see if it warps more" option is that Bradley won't keep making his aluminum arms forever. With the mandatory upgrades out of the way, you can probably expect a good deal more life out of the printer. The BW arms are genuinely a worthwhile print quality improvement and leveling frequency reduction upgrade even aside from the warping issue.

[perform...@gmail.com]

Chris - If you're willing to try arm stiffeners instead of the full aluminum arms, please consider ours.  The bottleworks arms are definitely a great upgrade, but if you're trying to save on price (and it sounds like you are) then our arm stiffeners might be the way to go. 

I'm not sure how warped your stock arms are, but if you get our stiffeners and have trouble putting them on, or find they cause binding, we'll gladly take them back as a return. 

Just thought I'd let you know in case you haven't seen ours yet. 
http://www.p3-d.com/aluminum-arm-stiffeners.html

[Chris Fastie]

Thanks for the info about the Performance 3D stiffeners. They might be the only ones that would work with my already warped arms. The wrap-around type could be a tight fit, and as Ryan says could put some pressure on the z-axis rods. I guess the big upgrade to new arms might be the way to go, but I have not yet seen the clear path to make the purchase.

[tramalot]

These work great, just heat the arms with a blow dyrer to get warped ones in. these are steel

http://www.ebay.com/itm/181477628454?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

On Wednesday, August 27, 2014 9:21:41 AM UTC-4, Chris Fastie wrote: