Technic General Discussion

[roppie11]

hello,

this question is kinda dumb, but is the EB-review of 42055 already out?

i have been away for 3 weeks and i can't find it right now. maybe i have to look harder

does somebody have a link?

thanks in advance

[KamalMYafi]

hello,

this question is kinda dumb, but is the EB-review of 42055 already out?

i have been away for 3 weeks and i can't find it right now. maybe i have to look harder

does somebody have a link?

thanks in advance

Hello!

The EB review of 42055 not yet out.

But Sariel has make the review of the A-Model and B-Model.

[Jim]

Not yet. Blakbird is working on it. He's making 3D renders etc. Will be posted soon-ish.

[tismabrick]

Is it ok to create a new topic about an excavator MOC prototype wip?

[Jim]

Is it ok to create a new topic about an excavator MOC prototype wip?

Yes it is ok, if you have any content to show, preferably some pictures.

[roppie11]

Hello!

The EB review of 42055 not yet out.

But Sariel has make the review of the A-Model and B-Model.

thanks i have seen sariels reviews already.

[Kit Fisto]

I`m not sure if I should post this question here, but I feel like I don`t have to create a topic for that.

So, can anybody explain me how this part works?

I`ve checked old instructions of sets where it was used (with old, one-holed cylinders) and the question is:

Is it possible to control both up and down motion of pneumatic cylinder with 2 holes(http://www.bricklink.com/v2/catalog/catalogitem.page?P=2793c01&idColor=3#T=C&C=3 ), using only one of these holes and this part:

[LucyCol]

In short 'No', the left port can only have air going in, the right port can only have air coming out, the middle port, in and out, they were designed to work with V1 of the pneumatic system with single port cylinders (http://www.bricklink.com/v2/catalog/catalogitem.page?P=4688c01#T=C) in which the air is sucked out in order to get it to retract.

[bonox]

You can still use that distribution block to make a two port cylinder act like a single port. Could be useful in situations where you can't run a hose to the retract port.

The idea is that you apply pump pressure to the centre port of the block, then run the other two block ports to the outer ports of a switch block. Then connect the centre port of the switch to one port on the cylinder (most often the bottom, but there's nothing stopping you from using either.

[Kit Fisto]

You can still use that distribution block to make a two port cylinder act like a single port. Could be useful in situations where you can't run a hose to the retract port.

That`s just what I wanted to know, thank you!

You are right - it`s the situation where I can`t run a hose to the second port

[bonox]

Good luck with it :)

Make up a demo with all the parts first, before you put the hoses into your model. I may be wrong on the hose order, but you'll work it out from some old instructions like the 8040.

I think part of the function of the distribution block is to stop the old style pump from sucking air out of the system when you release it.

edit: here is a great demonstration

http://lego.brickinstructions.com/08000/8040/002.jpg

Edited August 21, 2016 by bonox

[Kit Fisto]

At first I have to buy this part from BL;D

I need to make a system with 4-valve compressor and 4 pneumatic cylinders(using only one port on each of them).I hope it will work..)

[RohanBeckett]

funny.. when you think about it, and look back...

its interesting that they designed it this way...

the cost of designing and producing this distribution block would have far outweighed the cost of just running a 2nd host to the top of every cylinder...

[bonox]

As a point of interest, might be worth checking whether you need an old style pump to make it work. The old one does not have a check valve, so when you pull it out (or the spring does it for you), it should create a vacuum that gets transferred to the left port.

The newer style pumps do have check valves, meaning that they will only generate a positive gauge pressure. You may want to check if you need to buy an old pump as well as the distribution block.

the cost of designing and producing this distribution block would have far outweighed the cost of just running a 2nd host to the top of every cylinder...

Perhaps, but there's more to it than just the second port. The original design requires only one seal and the cylinder is entirely made of plastic from the same injection molding processes as all their other bricks. The top port requires a second (shaft) seal and they introduced metal for this, which was a step outside their expertise. I think I can see why they would have taken the approach they did.

If you have a collection of designers on staff, costs to come up with new parts isn't really significant over a large production run. Indeed for most manufactured plastics, it's the raw material which makes up over 3/4 and often closer to 90% of the total product cost once you get production scale wound up. (the rest is design, tooling, packaging etc).

But to introduce new materials and production requirements, perhaps even outsourcing them and then having to deal with the incorporation of outside supplier parts into your own production chain may have pushed them in the direction that they did

But what do I know! ;)

[Kit Fisto]

Well, I`ve recently got that part.

The problem is that it`s working only in one direction( In OR out movement of cylinder).

Changing the postition of the switch doesn`t make the valve to move in(while the pump is in action, ofc)

Is it the case pneumatic brick is broken or am I missing something?

[zux]

Isn't this pneumatic brick supposed to be connected both its ends to single pneumatic valve (top and bottom) to function? It won't work with single connection pneumatic valves.

[Kit Fisto]

Well, I have seen some mocs that use pneumatic valves with 2 ends, but only one of them is connected to the air.Just like this great

crane from Makorol:

So, what`s the secret of such systems?

[allanp]

Gravity is used to lower the boom. They simply omit the hoses between the retract ports of the cylinder and the valve.

Edited September 18, 2016 by allanp

[bonox]

Well, I`ve recently got that part.

The problem is that it`s working only in one direction( In OR out movement of cylinder).

Changing the postition of the switch doesn`t make the valve to move in(while the pump is in action, ofc)

Is it the case pneumatic brick is broken or am I missing something?

I mentioned the check valve in the pump in my previous. If you take off the pump from the block and suck through it with the switch in the position corresponding to the suction port on the block, will it retract then? If it does, then you need an old style pump. If not, your block may be broken.

[skaah]

> If it does, then you need an old style pump. If not, your block may be broken.

I think it's the pump, these tiny pumps don't "suck" only "blow".

[Epic Technic]

I recently made a technic crossbow purely for power/damage and I was wondering if it is appropriate to post it on this forum, what is Eurobricks' weapons tolerance?

[dr_spock]

I recently made a technic crossbow purely for power/damage and I was wondering if it is appropriate to post it on this forum, what is Eurobricks' weapons tolerance?

I posted a functional Technic crossbow in Special Theme last year -> http://www.eurobricks.com/forum/index.php?showtopic=107328

It seems to be ok there. If yours doesn't fit in Technics, MODs will move it.

[That_LEGO_Guy]

I've been tinkering with pneumatics for the last few days and the sizes of the pre cut tubing is very annoying, it's rarely the size you want or the quantity needed. Im yet to go at it with a pair of scissors and cut the longer lengths like what used to happen with 8455 and others. im wondering what your solution to the problem is: do you find a 3rd party tubing substitute, where do you get it? Do you buy extra long lengths  then cut to size or build around the sizes you have.

[Jim]

If I am not mistaken there's a link to 3rd party tubing in the contest information topic.

[Milan]

All you need for 3rd party pneumatic hoses.