Reason for unsupported linear bearing

I am embarking on making a few mods to the bed in order to reduce sag, reduce the offset and make it a bit more sturdy. The plan is to go full 6mm aluminium, remove all the nut traps for threaded holes, and obviously add in a few cutouts to keep the weight down as far as possible. I am also looking at the linear bearing which is all on ts own. It is the only bearing that doesn't have a printed support. In fact every time I pull a part off the bed the lack of support causes the bed to lift. In theory if you push the bed back down so that the bearing is resting on the wood cutout it should all be ok, however I feel that I could put in a pull support so that there are less degrees of freedom on the bed.

The question is twofold:
1) if I make these mods will I be out of warranty?
2) Is the lack of support done for a reason - such as thermal expansion?

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Ormerod 313

Hi Tracyb, I've conjectured like you that it's to allow some freedom (just supporting downthrust in Z, and floating in X and Y) to prevent jamming if the slides aren't parallel or properly spaced (from inaccuracy in cutting/fitting, or expansion) - some people have reported success using cable ties to hold the strut down on the front bearing so I guess the tolerance is pretty good.

It's up to Ian to advise on warranty issues, but I can't see any reason not to (unless you want a warranty replacement for the strut if you've drilled it and it snaps )

Ray

Hi tracyb

We encourage people to adapt their printer in anyway they see fit. We'll honour the 1 year warranty on all the parts we supply, for manufacturing defects. If there's a case where a part has failed and it's not clear what has happened, we take a view on it, but we don't expect people to claim a warranty if they've hit it with a hammer!

Ian
RepRapPro tech support

I've cabled tied my forward bearing, and its allot better. I did think about printing a bearing holder similar to the others on the
machine.
I want to mod my bed and add another bearing at the front, together with two more Ribs. I did ask RepRap (three times) for a quote on the parts I wanted, but had no reply. I did want to use another two of the laser cut ribs, and add a stringer (beam) between them near the front face to make it really solid.
I also wanted to use the laser ribs as they are great quality and lite...

However, I've had no reply from them so will have to give up and work something else out....

Kim

Thanks for the response Ian, the Ormerod doesn't belong to me but my company, even though I am the one doing all the fiddling. I didn't want to get nailed later on if my new bed was causing problems. Once I have done the design I will try and put the stl files on the forum to see if anyone else can add their brain power to mine. I am going to try add a new support to the bottom bearing and possibly add springs like johneato to aid in the levelling. Even though I know the software can compensate it is best to start off with a fairly level bed and let the software compensate of +-0.2mm, not +-1mm as my bed is currently doing. I have access to a full workshop with 2 cnc mills and a cnc lathe so I hope that I can keep the weight down as much as possible by machining out much of the excess material

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Ormerod 313