melting and fusing Lego

[Aerolight]

A while ago I built 6x6 tuck that used worm gears in the axles, and while climbing a steep ramp the whole drivetrain (2 xl motors) locked and would not move forward or back. When I took it apart I found a half stud axle spacer was fused into a 5x7 frame by the worm gear that was behind it( pushing into it). It took a pair of pliers to remove it leaving a frame with little marks while the spacer had lost about a third of its total length.

Since this a few years ago I had not encountered melting Lego due to friction (although I have done it via other means..) until.

I just finished my highest revving vacuum engine ever (by far the highest revving I have ever seen and part of my 5 world record project(coming soon)). And after revving it up and down a few times I decided to stress test it at max power to check if any part needed improvement, after less than 10 seconds of continuous max power on the vacuum the revs dropped significantly. Took me a few minutes to find the cause, one of the pistons had melted at the edges causing it to grind against the barrel; it had just cooked a piston!

So I was wondering if anyone else had experiences friction melting Lego?  

[J159753]

As a child I tried to create a functional Schienenzeppelin (https://en.wikipedia.org/wiki/Schienenzeppelin) using https://www.bricklink.com/v2/catalog/catalogitem.page?P=2740c01#T=C, and several 4x5 9V technic motors. It went beautifully along a stretch of straight track once, but when I tried a second time I found the propeller had melted part of the 1x4 technic beam that held it. 

Edited May 6, 2021 by J159753

[Nazgarot]

I've also done som testing with that prop. I melted one trying to gear it up and power it with a buggy motor for a hover craft. It did not work very well, but moved a little bit before the revs suddenly dropped. The prop was a complete loss, and is quite hard to come by... I did however find out it is threaded when I tried to get i loose and that it is possible to remove the 24 tooth gear to replace the 1x4 studded beam, and this has proven invaluable in experiments with propeller propulsion tests. It is by far the best prop Lego has ever made, and being able to dismantle it at replace the studded beam opens up a lot of possibilities. I have not melted any more of them though. I took too reason and placed some omni wheels below the hovercraft, and any other propeller powered experiment since... :)

_ED_

[ukbajadave]

On 5/6/2021 at 10:33 PM, J159753 said:

As a child I tried to create a functional Schienenzeppelin (https://en.wikipedia.org/wiki/Schienenzeppelin)

Nothing to add to the thread as I've never melted or fused any of my parts but that railcar! What a fantastic looking machine.

[MinusAndy]

I wrecked a fair pile of beams axles and gears when I was a kid by building a large scale model of my dads microlight. I just built the trike part at a scale using the big technic wheels, added the radio gear from a Tamiya car and powered it with a large plastic propellor and a 540 motor. The prop was geared down and it very quickly started using the axles as spools for polymer string melted out of the beams. It was a brief but glorious model.

[1974]

Epic! I had Tamiya cars and loads of Technic back in the 80's but i never did something as cool as that. All I managed to do was a to make a LEGO chassis for a my lowly Nikko Panther (?)

[MinusAndy]

I lubed it with margarine and got another 30 seconds of runtime out of it but ultimately it destroyed itself after a couple of passes down our driveway.

[2GodBDGlory]

4 hours ago, MinusAndy said:

I lubed it with margarine and got another 30 seconds of runtime out of it but ultimately it destroyed itself after a couple of passes down our driveway.

That sounds like a nice, cheap lube! Maybe I'll use it someday on my hobby-powered models.

[TechnicRCRacer]

I’ve never had any parts fuse themselves together besides some old polycarbonate plates, but there are some “problem areas” in certain sets that lead to parts breaking. There are two DBG 13L beams in the bottom of the Arocs chassis that snapped in the same place after it fell off my shelf. The unreleased Osprey apparently chews through gears as well.

[Toastie]

13 hours ago, TechnicRCRacer said:

The unreleased Osprey apparently chews through gears as well

Oh come on! This was not the reason! It was "not" released because of a dozen of folks protesting in Germany!

On 5/8/2021 at 6:13 PM, MinusAndy said:

I lubed it with margarine and got another 30 seconds of runtime out of it but ultimately it destroyed itself after a couple of passes down our driveway.

Hee hee. Nice one!

Well I may be wrong here, but I believe these are the reasons that they don't make internal combustion engines from ABS anymore. They switched to metal some years ago. Same with breaks and axles and differentials and so on.

Best
Thorsten 

[2GodBDGlory]

4 hours ago, Toastie said:

Oh come on! This was not the reason! It was "not" released because of a dozen of folks protesting in Germany!

Hee hee. Nice one!

Well I may be wrong here, but I believe these are the reasons that they don't make internal combustion engines from ABS anymore. They switched to metal some years ago. Same with breaks and axles and differentials and so on.

Best
Thorsten 

Speaking of plastic engines, I remember reading this article recently about testing plastic pistons in a real engine. It doesn't go well...

https://www.roadandtrack.com/news/a36317881/plastic-pistons-test/

[Aerolight]

Rip some more parts

One of my trucks has the lowest gear reduction ever (over 1/100 in the axles) so to get it to go any speed the centre diff has to spin at some speed. 

well I geared it up 3 times over what it was before and... 

20210825_144057[1] by michael waterfield, on Flickr

20210825_144603[1] by michael waterfield, on Flickr

The thing with the centre diff and cv joint is strange, all my strength wont remove it, yet it is still free to move and works perfectly. I think there is a lip inside the frame and a grove in the axle caused by the heat.

I think it will be fine with lubrication (as this happened dry) but the centre diff was spinning well over 5000 rpm when this happened (the wheels took less than a second to make a full revolution). 

[Johnny1360]

1 hour ago, Aerolight said:

Rip some more parts

One of my trucks has the lowest gear reduction ever (over 1/100 in the axles) so to get it to go any speed the centre diff has to spin at some speed. 

well I geared it up 3 times over what it was before and.

I think it will be fine with lubrication (as this happened dry) but the centre diff was spinning well over 5000 rpm when this happened (the wheels took less than a second to make a full revolution). 

Now sure why but I am literally laughing my megablocks off, picturing this scene in my mind. A video would have been so cool.

Thanks for that.

 

Edited August 25, 2021 by Johnny1360

[Aerolight]

Finally finished my big truck (100-1 axles) and while I tried to be careful to not go full speed for to long I still managed to melt the rear cv axle almost all the way through a 5x7 frame. 

 

So finally I drilled out the frame hole to fit an inner sleave made of stainless steel (glued to the cv) and a outer sleave made of brass to the frame, and know it works perfectly I just need to make the modification the to front cv now. 

[astyanax]

This thread is so painfully hilarious 

[aFrInaTi0n]

On 3/9/2022 at 9:16 PM, Aerolight said:

Finally finished my big truck (100-1 axles) and while I tried to be careful to not go full speed for to long I still managed to melt the rear cv axle almost all the way through a 5x7 frame. 

 

So finally I drilled out the frame hole to fit an inner sleave made of stainless steel (glued to the cv) and a outer sleave made of brass to the frame, and know it works perfectly I just need to make the modification the to front cv now. 

I am having a RC Superbike with a single swingarm for the rear wheel - regular ABS plastic is meltiung there due to forces being applied (gravity, tension of the chain) - I solved it by a special 5L liftarm with a ballbearing which are sold by a British company. Those work out great and I wish more of the brands would go into that direction..