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Lasse D

Model Team: Oshkosh P15 Aircraft Rescue Fire Fighting vehicle

15 posts in this topic

After half a year of researching, planning, building and rebuilding, I can now finally present my latest Model Team creation:

1977 Oshkosh P15

1oskosh3.jpg

Here's a video of it in action.

It is my first scale Model Team creation (1:30) of a real vehicle. I have aimed for a high level of detail, while still maintaining the functionality.

Here are some more clear samples of the pictures I used in the video

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2around04.jpg

around06.jpg

2around06.jpg

around09.jpg

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2around11.jpg

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Functions

Apart from smallest moving parts, such as doors

3interior.jpg

all functions are motorized using Power Functions remote control.

Steering is with dual tooth racks to minimize the width

3beneath_front.jpg

An NXT motor was the best for the drive in this model. It allows for a differential on each axle while only using 3 additional cogs

3beneath_rear.jpg

The motor for the pumps is an RC motor which is switched on using a 9V switch to avoid going through a PF receiver (to maximize the power and run without having to hold down a button on the remote)

3beneath_mid.jpg

The 9V switch is beneath the receivers

3inside2.jpg

To the left of the 9V switch there is a mechanical switch for the pneumatic hose. With this you can choose the active cannon. (seen more clearly in the video)

I use a bottle to hold the water. All other parts are from LEGO, and if you insist on using only LEGO parts, you can use a small air tank instead, as I did with the Rosenbauer ARFF

3bottle_vs_airtank.jpg

It is all nicely packed inside

3roof_off.jpg

The cannons turn together with the steering and their height is controlled using flexible tubes

3rear_cannon2.jpg

Stats

Just for fun. Here is a comparison with the real model. The last numbers in the rows are what you get if you multiply the numbers from the LEGO model up to the real size.

stat: LEGO, real, scaled

length: 48cm, 14,28m, 14,40m

width: 10,4cm, 3,10m, 3,15m

Weight (full): 2,446kg, 59410kg, 66042kg

Water: 0.25L, 24180L, 6750L

HP: 2.03W, 884HP, 74HP (NXT motor power found here)

Brickshelf gallery with more pictures.

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:oh3: L you have done it once again my friend.

I mean two water cannons :oh: Now that is perfection.

Well done :sweet:

Don't know about the music on the video though. :devil::grin:

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This looks fantastic! I can see why it took so long to build this, since nearly everything really works and the fact it looks incredibly realistic :thumbup: .

We are being threated here with two superb fire-engines: one modern one (this one) and a classical one!

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This is awesome. Once again you make everything I make look horrible :sceptic: . LEGO should hire you.

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A magnificent creation. It doesn't quite match your Coca-Cola truck in overall functionality, but the detail level is outstanding and it closely resembles the real vehicle it's based on. :thumbup:

I think the water system is the highlight of this model though. Your pump is quite impressive and shoots the water a long way. I have heard of using water in the Lego pneumatic setup but never tried it myself before. Are they still usable with air after that?

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An excellent piece of modelling :thumbup: I'm glad you have the preseverance to finish a model of this size. My Technic / Model Team vehicles usually stop with the chassis.

I think the key to using water with pneumatics is to avoid straining the valve seals with water pressure. In my experiments years ago I found that a non-return valve would not stand water because of the pressure (I connected the water tank to the inlet nozzle, a pump on the middle hozzle and a hose on the outlet nozzle).

Lasse D has avoided this by supplying air pressure to the tank from the 6 pumps and having only static pressure of water on the switch valve seals. I expect the switch valve will leak after a while but it depends how much pressure is built up and whether the valve can be re-greased to maintain the seal. I would not recommend operation of a pump under water as an alternative.

Use with air depends on how good the seal is. Re-greasing may restore performance as long as peak pressure (and hence bending of the parts of the switch valve) has not exceeded the elastic limit of the parts. I have some older pneumatic switch valves where the tabs holding the side panel onto the main body have worn, reducing the seal effectiveness.

Which grease is used to seal the valves? Might it once have been lithium grease (now banned as carcinogenic)? If so, Teflon grease is now used as an alternative for bikes, so I wonder if that's the one to use.

Mark

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Wow! :wub: Stunning work as always. I love the pump picture. :sweet: I used a spare motor for an air compressor using 2 of those pumps and it was quite effective. But 6! Oh my! :oh:

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I have heard of using water in the Lego pneumatic setup but never tried it myself before. Are they still usable with air after that?

It does. Pumps and actuators can't take it (the metal gets stained), which is why I have kept the pumps away from the water.

I think the key to using water with pneumatics is to avoid straining the valve seals with water pressure. In my experiments years ago I found that a non-return valve would not stand water because of the pressure (I connected the water tank to the inlet nozzle, a pump on the middle hozzle and a hose on the outlet nozzle).

Lasse D has avoided this by supplying air pressure to the tank from the 6 pumps and having only static pressure of water on the switch valve seals. I expect the switch valve will leak after a while but it depends how much pressure is built up and whether the valve can be re-greased to maintain the seal. I would not recommend operation of a pump under water as an alternative.

Use with air depends on how good the seal is. Re-greasing may restore performance as long as peak pressure (and hence bending of the parts of the switch valve) has not exceeded the elastic limit of the parts. I have some older pneumatic switch valves where the tabs holding the side panel onto the main body have worn, reducing the seal effectiveness.

Which grease is used to seal the valves? Might it once have been lithium grease (now banned as carcinogenic)? If so, Teflon grease is now used as an alternative for bikes, so I wonder if that's the one to use.

Mark

I had a switch in the first prototypes, but water can't get through fast enough. The switch in the final version is made by bending the tubes to block the cannons. I have not experimented enough with the switched for the seals to break (they are quite expensive).

Wow! :wub: Stunning work as always. I love the pump picture. :sweet: I used a spare motor for an air compressor using 2 of those pumps and it was quite effective. But 6! Oh my! :oh:

The first version had 8... and didn't work :tongue:

4building1.jpg

Edited by Lasse D

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Incredible as always. The level of detail is beyond anything i've seen. And the fact that it has a functioning water cannon... Wow. Stunning. Great work my friend. I may be contacting you in the future regarding a project i'm going to start.

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It's not very often that a MOc leaves me pretty much speechless. This is great. It looks a lot like the real thing, which is no mean feat by itself, but it's the functionality that is really jaw-dropping.

Cheers,

Ralph

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You've done it again Lasse, there's nothing i don't like about it...comment on this...yeah :thumbup::thumbup:

I envy your technic skills, it's clearly shown that you've been building these type of systems for a long time now.

Keep it up!

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I am very suprised that this thread only has one page of reply's. This is just as good if not better han your Coca Cola truck in my opinion.

By the way did you ever think of making copies of you creations to sell. They would go like hot cakes. Or even just instructions. They would also sell very well.

Just a thought

Buttons

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Incredible as always. The level of detail is beyond anything i've seen. And the fact that it has a functioning water cannon... Wow. Stunning. Great work my friend. I may be contacting you in the future regarding a project i'm going to start.

Thanks. I can always help a little if there are some Technic-details people need hints for.

I am very suprised that this thread only has one page of reply's. This is just as good if not better han your Coca Cola truck in my opinion.

By the way did you ever think of making copies of you creations to sell. They would go like hot cakes. Or even just instructions. They would also sell very well.

Just a thought

Buttons

With 8 people replying to one of my threads, this is actually one of the most active ones I have ever created :classic:

I'm not into making a profit on anything LEGO-related. It's just a hobby, but others can feel free to do so if they can copy the design. As for instructions of huge constructions: never again!

I'm happy as long as Ralph is left speechless :grin:

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That's absolutely fantastic; so many features! I absolutely love aircraft/airport MOCs and this is certainly a new favourite.

Laurie

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