Help with Technic Bushes & Half Bushes

[le60head]

Hey there folks!

I wanted to ask for some advice on technic bushes & half bushes.

I am noticing that many of them are cracking, and i'm trying to figure out why. Though they're cheap on bricklink, i'd like to avoid damaging them as much as possible, or figure out which ones are the most durable.

So here's my question:

In your experience, have you noticed whether older ones or newer ones are more prone to cracking?

Also, do you think that the cross axles have changed during the years? I suppose due to slightly different thickness, they could be the cause as well.

Any replies would be greatly appreciated.

Thanks!

[DLuders]

I have heard that the RED Technic Bushes are made of a more-brittle plastic than the Light Bluish Gray ("bley") Technic Bushes. The Light Gray bushes or Light Gray half-bushes are from older sets and are probably USED (not new), so I would use the (newer) Light Bluish Gray version. The newer plastic formulations are probably the most resilient.

While the Technic Bushes are made from ABS, the Technic Axles are made from a different plastic. If you buy them "new", you will ensure that you will get maximum fatigue life.

Edited November 20, 2011 by DLuders

[le60head]

Thank you, DLuders!

I'll examine the parts to confirm what u said.

If i learn something new i'll share.

[KEvron]

"any solutions?"

buy more. heh.

yeah, i've had dozens of both 1/2 and full bushes, and in all colors old and new, fail on me. eventually, they'll fail with regular use. the best solution is to stock up on them.

KEvron

[le60head]

eventually, they'll fail with regular use.

Thanks Kevron!

Since most LEGO parts last well more than 20 years under normal use, I expected the same from technic bushes :) I'd say ALL parts except the bushes then!

Your reply was much appreciated!

[Sokratesz]

The old toothed half-bushes are very prone to cracking, I assume because the plastic becomes brittle after (10, 20, 30) years and lots of exposure to sunlight.

- Sok.

[le60head]

Strange, I always thought they were the strongest.

Thank you for sharing your experience in this matter!

[DLuders]

@le60head: I think that Sokratesz was referring to the old toothed 4265a (Type 1) Technic 1/2 Bush (first picture below), which has more sharp 90-degree corners where "stress concentration" can occur. The 4265b (Type 2) Technic 1/2 Bush and modern, smooth 4265c Technic 1/2 Bush (second and third pictures below) have fewer 90-degree sharp corners, so the stress concentration (and potential for cracking) is less:

[le60head]

Thanks DLuders!

That was exactly the information I was looking for!

Next time i'll order the newer type bushes :)

[Erik Leppen]

I expected the same from technic bushes :) I'd say ALL parts except the bushes then!

Parts like

have the same problem at the bush-like parts as bushes...

So it is - unfortunately - not a problem of just bushes!

[zewy623]

whats with the half-bushes having the almost gear looking side? ive seen them on old sets before but i never understood why they were like that.

[KEvron]

whats with the half-bushes having the almost gear looking side? ive seen them on old sets before but i never understood why they were like that.

lego used to produce elements which interlocked with those teeth:

, etc.

imo, they never fully developed the possibilities for this flange, and now it's gone the way of the dodo.

KEvron

[Blakbird]

whats with the half-bushes having the almost gear looking side? ive seen them on old sets before but i never understood why they were like that.

See here. They were early versions of angle connectors. Here is an excellent example of what you could do with them (see the canopy):

[zewy623]

Thanks, im still not completely sure how they worked, but maybe someday ill get some off of bricklink and mess around with them since im more of a hands-on person

[le60head]

Parts like

have the same problem at the bush-like parts as bushes...

So it is - unfortunately - not a problem of just bushes!

True. I guess now u understand why i started this topic

Yesterday two of those snapped: ( one right after the other)

I hate when it happens

I think there's a lot of sence in what DLuders said:

that parts such as bushes or connectors become worn and stressed in time, and the time comes when they simply crack. So what he recommended is to buy new parts ( unused newly produced ones)

But i suspect, that some of the older parts were kind of strogner? I mean, made to be stronger.

Have any of you guys noticed that ?

-------

@Zewy

The "toothed half-bushes" and the other toothed parts were used in the following way:

Most parts have either a cross-axle hole: (x) or a round hole: (O)

The ones with the X-hole could be placed on a cross axle in 4 positions:

at 0, 90, 180 and 360 degrees.

The parts that have a toothed end, like the toothed half-bush can be mated with the toothed half bush and in this way placed on a cross axle at 16 different positions, at every 22,5 degrees.

Here's a quotation from technicopedia:

There are a total of 16 teeth around the circumference, allowing the part to be mated with other toothed elements at any angle which is a multiple of 22.5 degrees, including of course 90 and 180 degrees.

Look at the way the connectors in the middle top of the picture are mated together:

Hope this explains it, sorry if i didn't express it clearly.

[tazzy007]

Hey there folks!

I wanted to ask for some advice on technic bushes & half bushes.

I am noticing that many of them are cracking, and i'm trying to figure out why. Though they're cheap on bricklink, i'd like to avoid damaging them as much as possible, or figure out which ones are the most durable.

So here's my question:

In your experience, have you noticed whether older ones or newer ones are more prone to cracking?

Also, do you think that the cross axles have changed during the years? I suppose due to slightly different thickness, they could be the cause as well.

Any replies would be greatly appreciated.

Thanks!

The older they get they are more likely to crack just try and buy more

[Sokratesz]

See here. They were early versions of angle connectors. Here is an excellent example of what you could do with them (see the canopy):

This was my first and still is my favorite Technic set ever :) It has a nice bunch of gears, a fancy mechanism for the landing gear and the canopy which was a pain to build (because of all the different ways it could go :D:D)

- Sok.

[zewy623]

@le60head

ok i understand now, i think. they were just used the pinhole so that they could be put at a number of angles other than the 4 on the crossbeam, right? but on most sets i see them on (note that i have not seen even an 8th of the sets that use them) they arent used like that, mainly the half bushes used on the end of a beam.

[KEvron]

....on most sets i see them on (note that i have not seen even an 8th of the sets that use them) they arent used like that, mainly the half bushes used on the end of a beam.

in the early days of technic, that was the only style of 1/2-bush offered. as the line progressed, various elements which meshed with the 1/2-bush flange were added to the catalog. in fact, the smooth 1/2-bush wasn't introduced until the early 90's.

KEvron

Edited November 23, 2011 by KEvron