Cracking of LEGO 1/4 Circle Gear Rack (banana gears)

[doug72]

Cracking of LEGO 1/4 Circle Gear Rack (banana gears)

I have been checking all my various GBC / MOCs which use these gears and found cracks in several of my older parts from the BWE etc.

It seems to effect only the yellow ones as have not found any cracks on the black versions.

The gear rack ends thin section with axle hole that connect to the next gear segment have cracked.
If you are lucky these can be repaired with Plastic Magic Weld.

 

Has anyone else had this problem?

Others which have completely broken off & the gears are now scrap.

This problem only seems to effect older yellow gear racks which have become brittle with age. None found on more recent purchases & none on any black gears.

I now take particular care when separating these gears and make sure you don't twist them as the 2L axle is pushed out.

Edited June 30, 2020 by Doug72

[astyanax]

I've been concerned this would happen ever since I saw cracks in Sariel's monowheel video (2:35)...

[DrJB]

That looks really bad. It appears many parts with similar geometry have such weakness, including those shown below.

  

The half-width cross-axle hole is notorious for this. The first time I saw this issue was with the 8480 Space Shuttle (Not sure how many forum members remember such set) . When I assembled it, all parts were fine. But few months later while on display, ALL 8 white thin lift arms that open the cargo bay, and the 8 yellow that make up the satellite had cracked.

 

 

 

Edited June 30, 2020 by DrJB

[nerdsforprez]

That is indeed very bad news especially since these gear racks are expensive parts.  Not to mention.... from BWE which really is not that old... yet.  I mean we have seen similar problems in pieces >10 years oldish (I know there is a lot of variability here) but in something relatively recent it raises my concern even further....

[Erik Leppen]

It was a matter of time before this topic would appear. I found the end axlehole to be a bad idea from when the part was first introduced (and also mentioend this on Eurobricks).

The black ones are newer, so they will show the same problems next year...

I did expect it to take a bit longer though.

I'd say, if the part is not usable anymore, just order a replacement part from TLC. They're still in production, I suppose. If TLC get lots of replacement part requests for this part, I hope they notice the problem.

Edited June 29, 2020 by Erik Leppen

[doug72]

Just ordered 8 new curved gear racks at £0.60 each.

[dr_spock]

I haven't encountered cracking yet.  I had mine sitting in this cylindrical shape for the last couple of years before finally getting around to disassembling it this spring. 

 

 

[Parazels]

6 minutes ago, dr_spock said:

I haven't encountered cracking yet.  I had mine sitting in this cylindrical shape for the last couple of years before finally getting around to disassembling it this spring. 

 

 

What the hell is this?!

[Bluehose]

2 hours ago, Parazels said:

What the hell is this?!

The shipping containers carrier LUGBC.

[DrJB]

That's the first time I see the Pick-A-Brick containers used in a MOC ... nicely done.

However, where does the satellite get its power from? I do not see any solar panels.

 

[SNIPE]

I have had one crack on me but it was my fault because I put an axle in it and yanked it too much

[TechnicRCRacer]

Had my BWE assembled until recently and all gears were fine.