Pnemuatic/Adjustable Suspension?

[__________________________]

Hi EB community,

I'm pimping out 10220 and I want to use adjustable suspension. The only solution I heard about was pneumatic suspension. I've investigated this, and I still don't understand exactly how it works. I've even asked respectable Technic FOLs like Sariel (http://sariel.pl/) and received derogatory and offensive remarks.

Can anyone explain if there's any better way to remotely adjust suspension on an RC Lego Model-Team style 10220 set? Also, if pneumatic's the best answer, how exactly does it work?

I would appreciate any constructive feedback. Thanks!

In exchange, I've attached what I think is my modded version of 10220, with some pretty mods. (Let me know if it's the original set file.)

10220_volkswagen_t1_camper_van.lxf

[Tommy Styrvoky]

well basically you have pneumatic cylinders on each axle axle and they are attached to the suspension. so when you use a valve to control what part of the air ride system receives air and that lifts the desired wheel/axle. You can choose to have different wheels being controlled by valves, all wheels being controlled by 1 valve or paired axles that can be actuated by a valve.

With the set you are planning to use as a base for it i think that a mechanical version would be better fit because you don't need a compressor, and large cylinders.

Edited May 17, 2014 by Tommy Styrvoky

[fasterthanlight]

It will be pretty much impossible to fit pneumatics into that model team set. You should take a look at how set 8297 accommodates for adjustable suspension!

Also, I laughed out loud about your experience with derogatory and offensive remarks from a certain someone, because thats apparently normal =/

[Rikus]

I'm pimping out 10220 and I want to use adjustable suspension.

[...]

Also, if pneumatic's the best answer, how exactly does it work?

Hi,

I already made many experiments with pneumatic cylinders used as suspension system, in the past.

Basically, you have to completely replace normal springs with pneumatic cylinders; by adding or removing pressure to cylinders, you can rise/lower your vehicle (it is the same technique used by Citroen hydropneumatic suspension system).

By using pneumatic cylinders in combination with soft springs, on heavier models, with the same method, you can make suspension system softer/harder.

For a small model like the T1, I think you could try to use 4 small cylinders, one for each wheel, moved with a pushrod system to use lesser space and/or to multiply leverage to have shorter/longer wheel movement.

Every small cylinder is capable of lifting over 1kg weight, so they will be enough for sure.

They could easily be actuated by a compact pneumatic autovalve, like

.

I suggest to link only one tube to lower chamber of pneumatic cylinders, so you'll act only adding/removing pressure on that chamber, that will allow a slower lowering of the suspension system (should you connect both tubes, by inverting the pneumatic switch you'll have the model lower itself too abruptly).

Hope this will help, somehow.

Edited May 17, 2014 by Rikus

[__________________________]

It will be pretty much impossible to fit pneumatics into that model team set. You should take a look at how set 8297 accommodates for adjustable suspension!

Also, I laughed out loud about your experience with derogatory and offensive remarks from a certain someone, because thats apparently normal =/

Thanks for the feedback everybody!

Also, 8297 looks very interesting. Can you (or somebody else) explain exactly how it works? Mechanical adjustment would eliminate the compressor, freeing up a good deal of space!

[Blakbird]

Thanks for the feedback everybody!

Also, 8297 looks very interesting. Can you (or somebody else) explain exactly how it works? Mechanical adjustment would eliminate the compressor, freeing up a good deal of space!

There is a good review at Technicbricks that shows how it works.

http://www.technicbricks.com/2008/12/tbs-techreview-06-8297-off-road.html

[Rockbrick]

anti roll bars would be an absolute requirement if using Hydraulic suspension setup

Citroen suspension is also self - levelling - i've yet to see that set-up in lego...!

(the system would have to run at constant even pressure and at least the front cylinders connected to rear in some way [i.e. push the front, the back gets affected]- adding removing air is what adjusts the height)

Edited May 19, 2014 by Rockbrick

[Sariel]

I've even asked respectable Technic FOLs like Sariel (http://sariel.pl/) and received derogatory and offensive remarks.

With all due respect, I gave you basics and referred you to my book for details. In fact, I told you about the 8297's suspension solution in the very first answer. Excuse me if I don't give you a complete recipe for the whole model - which is what your many, repetitive and onerous comments come down to.

I consider what you wrote a slander, and I'm reporting it to the EB staff as such.

Edited May 19, 2014 by Sariel

[Zerobricks]

Hi EB community,

I'm pimping out 10220 and I want to use adjustable suspension. The only solution I heard about was pneumatic suspension. I've investigated this, and I still don't understand exactly how it works. I've even asked respectable Technic FOLs like Sariel (http://sariel.pl/) and received derogatory and offensive remarks.

Can anyone explain if there's any better way to remotely adjust suspension on an RC Lego Model-Team style 10220 set? Also, if pneumatic's the best answer, how exactly does it work?

I would appreciate any constructive feedback. Thanks!

In exchange, I've attached what I think is my modded version of 10220, with some pretty mods. (Let me know if it's the original set file.)

I think the best way to make pneumatic suspension is to connect the valve parallel to suspension. This way when suspension gets too low the valve is switched and air is pumped in the cylinder. If the suspension is too high the valve iss witched other way and air is relased. Here's a video of a truck with suspension from Sheepo:

Edited May 19, 2014 by Zblj

[Jim]

TheLegoExpert and Sariel, check your PM.

Let's continue on topic from now on!

[Rockbrick]

sheepos truck is amazing - clever use of height correctors....

i don't think anyone can ever top this - one should stick to the 8297 method of height adjustment its very compact and does the job

[__________________________]

Thanks for the latest feedback guys! I'm looking into 8297, but I'll consider other suggestions!

[Imanol BB]

Something that would be nice is that there were lego lifting air bags, or suspension airlifts, they would be awesome to make a low rider, hot rot or others cars.

[DrJB]

What I did not read in this thread (I may have missed it) is what is the OP after with the adjustment feature? There are two main reasons adjustable suspensions are used in real life:

1. Adjust the height of the vehicle for ground clearance

2. Adjust the stiffness of the (air) springs to increase load bearing capacity.

For #1, a mechanical solution is perfectly feasible/sufficient

For #2, you'd need to go pneumatic or possibly a mechanism that pre-compresses (preload) the springs to move the operating point and increase load capacity.

Which one are you after?

[__________________________]

What I did not read in this thread (I may have missed it) is what is the OP after with the adjustment feature? There are two main reasons adjustable suspensions are used in real life:

1. Adjust the height of the vehicle for ground clearance

2. Adjust the stiffness of the (air) springs to increase load bearing capacity.

For #1, a mechanical solution is perfectly feasible/sufficient

For #2, you'd need to go pneumatic or possibly a mechanism that pre-compresses (preload) the springs to move the operating point and increase load capacity.

Which one are you after?

I care most about 1, but I also want to do 2.