General Part Discussion

[2GodBDGlory]

In some circumstances part 6571 can be used like a super-short towball liftarm, but it's still inconvenient, and an expensive part!

[1gor]

22 minutes ago, 2GodBDGlory said:

In some circumstances part 6571 can be used like a super-short towball liftarm, but it's still inconvenient, and an expensive part!

Well, I have several of those parts, but how to make it stiff enough for motorized MOC?

[2GodBDGlory]

1 hour ago, 1gor said:

Well, I have several of those parts, but how to make it stiff enough for motorized MOC?

This is what I was thinking of:

It's not quite in system, because these parts can't snap down quite far enough onto the hubs towballs, but it certainly works well enough for a builder with loose standards like me!

I haven't tried that in a motorized model, so it's hard to say how well it would hold up, but here's a reinforced version I threw together:

[SNIPE]

17 minutes ago, 2GodBDGlory said:

I like it!.

[1gor]

@2GodBDGlory, idea is very good, but in my case it ended up to much loose; i have tried something like this with vertical support like yours, but with shorter 5L suspension arm instead of link (and put 2 thin 1 x 3 listarms and 27940 connector, but it didnt work out the way I wanted). There is always a different approach - to make reduction where motor is...

Thank you; perhaps I'll be smarter in the morning; who knows.

Kind regards

Edited February 21, 2024 by 1gor

[howitzer]

6 hours ago, gyenesvi said:

That means no new 5L steering links :(

Also, it's pretty sad that they have budget for this kind of unique (=not so reusable) A-arm with towball sockets, but they can't make generic technic beams with towball sockets in more sizes.

Or towball sockets with pin or axle...

[msk6003]

One piece wheel? WHY!

[Ngoc Nguyen]

1 hour ago, msk6003 said:

One piece wheel? WHY!

SO that it can be sold to Monkey D. Luffy.

[1gor]

Perhaps this post should go also here...

 

 

Edited February 23, 2024 by 1gor

[amorti]

Just realised the 1:5 motorcycle tires are too large at 139mm diameter.

The correct tyre for the BMW is a 200/55-17, which is about 652mm across. Divide that by five and it would be 130.4mm.

The front tire is a 120/70-17 represented by 132mm in Lego but should be @120.

No wonder the wheels look too big on my RC bike with correct wheelbase to scale of something like an R1 1415mm/5 = 283mm.

They are...

Edited February 23, 2024 by amorti

[1gor]

29 minutes ago, amorti said:

Just realised the 1:5 motorcycle tires are too large at 139mm diameter.

The correct tyre for the BMW is a 200/55-17, which is about 652mm across. Divide that by five and it would be 130.4mm.

The front tire is a 120/70-17 represented by 132mm in Lego but should be @120.

No wonder the wheels look too big on my RC bike with correct wheelbase to scale of something like an R1 1415mm/5 = 283mm.

They are...

That is common Lego problem for us MOCers; limited tire sizes make us hard to make accurate (enough) models

[amorti]

2 hours ago, 1gor said:

That is common Lego problem for us MOCers; limited tire sizes make us hard to make accurate (enough) models

It's not so much the lack of sizes, but the sizes are wrong.

The rear is scaled 1:4.7, while the front is 1:4.5.

Neither is scaled 1:5 as listed on the box.

[1gor]

58 minutes ago, amorti said:

It's not so much the lack of sizes, but the sizes are wrong.

The rear is scaled 1:4.7, while the front is 1:4.5.

Neither is scaled 1:5 as listed on the box.

This is also one example of (rotten) compromise...

[R0Sch]

LEGO sure loves their rainbow. These new cam and piston pieces are weird. But they do allow the pistons to move even without gravity helping keep the pistons down. Never saw a 3L axle with stud being marked as a 3.2 before and LEGO also calls it officially "CROSSAXLE 3M WITH KNOB".

[SNIPE]

2 hours ago, R0Sch said:

LEGO sure loves their rainbow. These new cam and piston pieces are weird. But they do allow the pistons to move even without gravity helping keep the pistons down. Never saw a 3L axle with stud being marked as a 3.2 before and LEGO also calls it officially "CROSSAXLE 3M WITH KNOB".
 

Yes, Lego's naming scheme is retarded, it makes finding parts in ldcad/pick a brick a nightmare.

[Ngoc Nguyen]

2 hours ago, R0Sch said:

"CROSSAXLE 3M WITH KNOB".

How did you find Lego's internal names for parts?

[gyenesvi]

These new piston pieces are nice, they do make life easier in dense builds, though I don't get why that extra spacer (the two collars) is required at the top under the stud. This way it won't fit into a full stud sized space under the hood, as the pistons stick out about 1.5 studs in their up position, while if that half stud would have been spared out, they would only stick out 1 stud, and the whole engine could have fitted into a 4 stud tall space (including the driveshaft). Not sure if that spacer has a function or if that's just for aesthetics (which would be a pity).

[Jockos]

31 minutes ago, gyenesvi said:

These new piston pieces are nice, they do make life easier in dense builds, though I don't get why that extra spacer (the two collars) is required at the top under the stud. This way it won't fit into a full stud sized space under the hood, as the pistons stick out about 1.5 studs in their up position, while if that half stud would have been spared out, they would only stick out 1 stud, and the whole engine could have fitted into a 4 stud tall space (including the driveshaft). Not sure if that spacer has a function or if that's just for aesthetics (which would be a pity).

I think they are there to help raising the pistons, as if they weren't there they might stuck. 

Actually, these new elements give me hope we get the same treatment for the bigger engine blocks, too.

[amorti]

@Jockos what improvements could you imagine for the larger cylinders?

Seems like they got it dead right all that time ago.

However, I'd take better crankshaft pieces which for example allowed a proper boxer configuration.

[Jockos]

25 minutes ago, amorti said:

@Jockos what improvements could you imagine for the larger cylinders?

Seems like they got it dead right all that time ago.

However, I'd take better crankshaft pieces which for example allowed a proper boxer configuration.

This is the exact reason for me, too, but I think they wouldn't fit in the existing configuration, so some tweaking might be needed.

[gyenesvi]

2 hours ago, Jockos said:

I think they are there to help raising the pistons, as if they weren't there they might stuck. 

Not sure how those would help. Where could they get stuck when raising? I think they would not even need to touch the bottom/top either, as the full range of movement seems to be less than half a stud, actually even a bit less than a plate, so there would be tolerance space at both ends against any jamming.

[allanp]

As much as I love new functional elements, I can't say I like these new piston/cam pieces. They aren't authentic to any real life mechanism that I know of.

[Stereo]

4 hours ago, amorti said:

@Jockos what improvements could you imagine for the larger cylinders?

However, I'd take better crankshaft pieces which for example allowed a proper boxer configuration.

Main one I see is a part for 90 degree offsets in the crank.  Like what you'd get by gluing two 2L thin liftarms together in a + shape.  A new rod piece that's more standard (half stud thick pinhole at the crank end, towball other end.) could be useful outside of engines too.  Or even take it a step farther, make 3L and 4L "rod" parts as thin liftarms with pinholes at both ends, and use a half pin as a wristpin in a new piston piece...  If you change the rod design, the two cylinder banks need a 1/2 stud offset from each other, but that's easy to build and also realistic to how engines are constructed.

Edited February 24, 2024 by Stereo

[2GodBDGlory]

3 minutes ago, Stereo said:

Main one I see is a part for 90 degree offsets in the crank.  Like what you'd get by gluing two 2L thin liftarms together in a + shape.  A new rod piece that's more standard (half stud thick pinhole at the crank end, towball other end.) could be useful outside of engines too.  Or even take it a step farther, make 3L and 4L "rod" parts with pinholes at both ends, and use a half pin as a wristpin in a new piston piece...

Yeah, something like the joiner parts here would be quite nice to achieve more realistic firing orders!

Image from https://www.thingiverse.com/thing:3517791

I should probably print some of those next time I build an engine that would require such a crank pattern...

[captainmib]

Can you fit two pistons on one cam?

To create a V-shaped engine?