[TC14] Excalibur (Top Spin)

[Erik Leppen]

In this topic I want to keep the progress for my TC14 (Theme park rides) entry. The first idea I got for a ride is a Top Spin with independent arms. I call it Excalibur because the inspirational ride from my home park (Walibi Holland) has that name. I won't literally copy that ride though, because it doesn't have independent arms.

More info on the real ride (in Dutch):
http://walibi24.nl/parkinformatie/attracties/sherwood-forest/excalibur/

Random photo of the real ride:

 

The real ride has water. I won't do that :)

The other inspiration is an unfinished version of the ride my cousin once built when I was younger. (I believe he used the Control Center to operate it.) This was in the studded age, and there are no pictures, but TC14 seems like the perfect opportunity to try and build such a thing.

I started by laying out the frame, getting a sense of size. It's huge (for my doing)

 

The arms are independent. This means two things.

1. one of the arms will need to bend inward so the bench can be at an angle without the whole structure deforming.

 

2. the connection with the bench needs to be flexible. As I also want to control the angle of the bench, I needed a U-joint type of connection (with 2 degrees of freedom, but control over rotation; as a normal U-joint). As a normal U-joint would not hold, I invented my own heavy-duty U-joint:

 
A Unimog ball joint goes through a turntable (it just fits). The turntable holds 4 ball-pins that connect to 4 ball-links on the other half using 6L links. (I'm happy they removed the stops on these links a few years back.) It does mean I have this weird 4x5 frame on the bench though, that makes the link unwieldily long.

The length of the whole things is dictated by the length of the vertical swing arms, and the maximum angle of my U-joint. I think I will make the swingarms slightly shorter, so that the whole thing can shrink a bit.

I also started some work on the bench. I made a test thing which whould basically be a cross-section showing only 2 seats. There's a little system for the restraints driven by the three 24t gears. I'm not happy with this system yet; I think the range of movement is too small.

 

This is what I have now. The next things to do are:

• Build a very strong and rigid studded frame for the base and support towers.
• Make the swingarms a bit shorter, so the ride can be shrunk a bit
• See if I can connect some of the seats to the main ride.

As far as I can see now, the ride will have the following 5 (main) functions:

• Rotate left swing arm
• Rotate right swing arm
• Rotate bench along its own axis
• Operate restraints
• Move entrance/exit paths out of the way

Hopefully I can combine the last two in one move, thanks to an idea by @pleegwat on the general information thread (and others who made suggestions, but I will probably try his solution first)..There are probably other functions to come, like operating the gates, but that will emerge when the build evolves.

I really hope I can get this done in time, and to my own satisfaction, because I think it's a pretty tough challenge :)

 

[Rudivdk]

Wow, you've set yourself quite a challenge... Very impressive start with those joints/angles in the frame. Nise idea on the restraints as well. Can't wait to see more of this one!

[kieran]

Looking, great. I have been on a few of these in my time, looking forward to the finished model 

[TechnicRCRacer]

There goes my model! It didn’t work anyway 

[Seasider]

I remember seeing one of these years ago I think at Alton Towers or Chessington in the UK. Looked totally insane

[Marxpek]

Nice to see this being built! I also considered to make this one (and made a prototype). Your version looks way more complex tho, I do not see why yet, but i will follow this with interest to find out!

[pagicence]

I'm very interested to see how this will rotate. With all the gears, ball joints, turn tables... will it rotate normally (parallel) or it would be some kind of mixer rotation?

[Erik Leppen]

21 hours ago, TechnicRCRacer said:

There goes my model! It didn’t work anyway 

Maybe we can inspire each other. I say if you don't have another idea, go ahead 

 

7 hours ago, Marxpek said:

Nice to see this being built! I also considered to make this one (and made a prototype). Your version looks way more complex tho, I do not see why yet, but i will follow this with interest to find out!

Why not join the competition and work out your prototype further? I think it's cool to see different people take on similar projects. 

 

5 hours ago, pagicence said:

I'm very interested to see how this will rotate. With all the gears, ball joints, turn tables... will it rotate normally (parallel) or it would be some kind of mixer rotation?

The idea is that the two swingarms will move independently. Which means there is no center bar (the horizontal tube that holds the big letters in the real version), because it would be in the way.

Anyhow, I have some progress, as I had most of the day today to build. First fo all I played with lots of different ideas for the bench and its restraint mechanism. I'm not sure if I found a good-enough idea yet, but the idea that seems the most promising is this one:

It uses a wormgear to drive the restraints, meaning it can't be backdriven. The idea is that the big 36t gear will couple with something in the floor of the base. The part with the transparent Technic teeth should come in the base and raise/lower together with the movement of the entrance/exit. It's a bit large though, I'd like to find something more compact.
I tried some other ideas, inclding a link-driven idea, but that wasn't reliable and took a lot of space. Also, it owuld need a system to prevent the restraints from getting loose. A wormgear seems the simplest way to achieve this.

I also have tried laying out the bench; which seems to be smaller than I hoped. (as in, small seat space)… I hoped for a slightly better ratio of seat area / ride size. I used some paneling to create a curved bottom, but I only have the 3x13 panels in weird colors, and I don't like all those colors together. So I'm not sure yet about the paneling. Or I may have to order black 3x13 panels.

I also worked on the frame of the base with towers. I went with a studded structure, which seems very strong so far. I have only built one side, the one that controls the bench rotation.

I also made the swingarm 2 studs shorter, so the radius of the swing motion is now 13 studs. Not very much, but enough I think for the idea.

Currently, the tower holds the gearsystem for the swingarm rotation, a gearsystem for the bench rotation, and a switch to couple or decouple the bench rotation. I hope that if decoupled, gravity will let it swing by itself (which is done on the real ride too, although the real ride only has a couple-decouple; when coupled, the bench is fixed relative to the swingarms).

Next up: build the other tower and swingarm; connect them to form the whole frame, put the bench between them and see if I can get the restraint coupling to work.

[Erik Leppen]

Yesterday's progress is a new base with both towers. It's 64 studs long (4 x 16) and surprisingly strong. The only disadvantage so far is that I'm kind of stuck with yellow as a color. I hope to find a color scheme that combines well with yellow and black.

My idea is to add some kind of an operator's panel at the front where the ride's motions can be controlled with levers. That will come at the front, attached to the 6 x 8 bricks sticking out. However, I played with a gearbox system, but that got too many gears for one motor to drive. So I'm not sure how I want to solve that. I'd rather not use RC, and I don't have the polarity switches.

[Jim]

I love the safety system for the seats. This is gonna be a fine entry!

[pagicence]

3 hours ago, Erik Leppen said:

I hope to find a color scheme that combines well with yellow and black.

Try with blue or white. More blue than white.

Edited July 16, 2018 by pagicence

[Aventador2004]

Didn't enjoy the real thing, but best of luck!

[Erik Leppen]

It has been a bit silent the last two weeks, but I haven't sit still. I have two updates: the new bench, and a coupling/decoupling system for the restraints/entrances.

I added some diagonal V-shaped plates to the bench (white plates), and I added a "floor" beneath it that has the same V's, attached to a platform that moves along 4 vertical axles. The photo above shows the platform in its bottom position, where it mostly sinks between the yellow beams of the base. In this position, the bench can freely move. In the picture below, the floor is in the top position, and holds the bench in place. The knob wheel in the middle of the floor will then attach to another knob gear on the bench, that will control the restraints.

You see an axle runing through the bottom of the base. This will move four linkages below the corners of the platform, to raise and lower it. It is now controlled manually by the knob (twin 12t double bevel gears) on the far right of the image, via a series of 24t gears (spur and crown) in the base, and then a worm to 8t on both sides. Here's a slightly better look on that linkage and gear system:

 

The other update for now is that I actually created a bench that I personally find really nice:

I went for groups of 3 seats, cheating a bit by sharing each blue 3x5 beam between 2 seats. That way I could get 3 seats into 7 studs. This way, I can make it look larger than it would be if each seat would be 3 wide, or even 4 if each seat would need their own restraint. So I went with a large single restraint bar. It may not be realistic for an inverting ride, but it gives me the ability to increase the number of seats to more realistic proportions. As you can see, it seats 24 imaginary riders :)

Also, you notice I have laid out a color scheme. I used the new yellow and red axles, and chose to use red as the color for the restraints so I could use the axles. Same for the yellow handrails. What I notice with this contest, and which I am sure many TC14 builders will recognize, is that I require lots of the same part in all kinds of places. For the 24 seats in 8 sets of 3, I needed 32 L-shaped 3 x 5 beams. That narrowd the options to red, yellow, blue, gray, black. The only color that stands out from the already existing colors is blue (which goes really nicely with dark gray). And aren't blue seats tradition in Technic models? So, parts availability dictated the color scheme I disliked so much on 42024...

For the final pictures, I show a cross section of the bench (without the frame) with restraints up and down (you can see the knob gear at the bottom):

\

 

The bench is quite heavy, so I will need some sort of counterweight on the arms (I counted on this, because I think the real ride has this too. Fortunately, I have 4 weight bricks.)

Next to-dos:

• adding the entrances, and connect them to the moving platform so they give access to the ride when stationary, but fold away when the ride moves
• motorizing the three main functions

Question: how would you suggest to do the motorization?

• one motor per function; RC to operate the motors
• one motor for everything, use gearboxes to operate the functions

Using RC feels weird on a ride that isn't actually remote controlled (I don't think actual remote control adds anything of value). But using only 1 motor will probably overload the motor. Are there other ideas? A Control Center or similar would be great, but I don't own any such things. Maybe I should bricklink a few PF polarity switches, but I reckon these aren't cheap. So this is an unsolved problem for the moment. Any insights?

Any feedback is welcome 

 

 

[pagicence]

There is some serious engineering going on here. I'm glad to see that you went with blue.

On ‎7‎/‎13‎/‎2018 at 7:21 PM, Erik Leppen said:

• Rotate left swing arm
• Rotate right swing arm
• Rotate bench along its own axis
• Operate restraints
• Move entrance/exit paths out of the way

How about you use 1 RC function for rotation; 2 motors in sync on each side to rotate the swing arms (I'm assuming you will need 2 because of the weight), and the bench will be co-dependent on that rotation (with all the gearing you have going on in the swing arms).

And power everything else on 2nd RC function; 1 motor to operate everything else, through some kind of gearbox with switches which you can mask as an operators control panel. Because all other functions are independent and they will not work in the same time, therefore you don't need much power for them.

Just tuck in (hide) the motors well somewhere, that they are not so obvious, and you are golden.

[Appie]

This looks very promising. Some very nice mechanics. I personally don't like the restraints per 3 seats, but understand the design choice.

PF switches are 7 bucks @ Lego, bricklink probably won't be cheaper. I wouldn't do RC, but perhaps 2 motors or a gearbox switching between your 3 arms functions and the restraints/entrance-exit mechanism with 1 motor? 

Have the arms follow a fixed routine of motions and then the ride ends. I think that's how they work in real life? One press of a button and the operator goes afk 

Queue the restraints/entrance mechanism at that point and done?

[Erik Leppen]

On ‎7‎/‎29‎/‎2018 at 1:13 AM, pagicence said:

There is some serious engineering going on here. I'm glad to see that you went with blue.

How about you use 1 RC function for rotation; 2 motors in sync on each side to rotate the swing arms (I'm assuming you will need 2 because of the weight), and the bench will be co-dependent on that rotation (with all the gearing you have going on in the swing arms).

And power everything else on 2nd RC function; 1 motor to operate everything else, through some kind of gearbox with switches which you can mask as an operators control panel. Because all other functions are independent and they will not work in the same time, therefore you don't need much power for them.

Just tuck in (hide) the motors well somewhere, that they are not so obvious, and you are golden.

To be honest, at the moment I think motorizing the extra functions isn't even necessary. The way I'm thinking right now, is to view the person viewing the MOC as the "ride operator", similar to a slot machine for example. Then, the "ride operator" can just turn a knob to lower/raise the restraints. There doesn't have to be a motor between this.

On ‎7‎/‎29‎/‎2018 at 9:44 AM, Appie said:

This looks very promising. Some very nice mechanics. I personally don't like the restraints per 3 seats, but understand the design choice.

PF switches are 7 bucks @ Lego, bricklink probably won't be cheaper. I wouldn't do RC, but perhaps 2 motors or a gearbox switching between your 3 arms functions and the restraints/entrance-exit mechanism with 1 motor? 

Have the arms follow a fixed routine of motions and then the ride ends. I think that's how they work in real life? One press of a button and the operator goes afk 

Queue the restraints/entrance mechanism at that point and done?

You're correct that in real life, the ride follows a pre-set program. But I kind of like the idea that the ride can be "controlled" by someone. Also, adding some kind of programmable unit somewhere would make things too complicated and large I think. I don't own any Mindstorms or similar things, PF remotes are the most advanced things I have.

Gearbox stuff would be cool, and I've toyed with this, but I think this would eat too much torque from the motor. I think I will need direct drive from the motors through a geartrain that's as simple as possible, so that all torque can be used to obtain a reasonable speed.

But I have put the PF switches on my BL wishlist and will probably place an order very soon.

For now, I have left motorization for what it is and focused on the entrance mechanism. Which, I think, turned out pretty cool. Also, I'm almost out of long (7, 9, 11) yellow axles, so I hope I don't need many more railings. I do still have a few 16L links in yellow though.

This is how it looks with the entrances up. This is the "enterable" position - riders can enter the bench via the blue stairs. Unfortunately though, the gray ball joint parts with half frames block the path to the rear row. This means that technically, riders can't enter the back row. But I think I leave it like this, because I see a Lego model as representing a thing instead of literally being it. So I don't mind if details are incorrect, and I consider those gray pieces to be "details". If the gray ball piece was the same size as the dark-gray ball-socket piece, things would be fine.

Here it is with the entrances down. The inner railings of the stairs fold down using a 9L link (connected to the black 3x3 T-beam connected to the studded frame at an angle) so the rotating bench doesn't touch them. The outer railings don't need to move away.

I also added a front blue platform, and two red gates. I continued using blue as "walkable platforms" and red as "safety", hence the red gate. This would be the area where guests can walk by, or a waiting area of some sort. I think it works really nicely. One thing that is not realistic is that the gates open towards the queue. Normally, the gates open towards the walking direction. But this is a minor thing.

The image below gives a better view on the linkage used to fold the inner railings. The stairs are simply connected to the moving bed (the thing with the white plates) at the top, and hinged at the bottom.

Here's the whole thing so far:

As you can see I also quickly used some gray frames to lay out the maximum reach of the counterweights at the other ends of the swingarms. This will be replaced by black studded things holding 2x6x2 weight bricks (2 per side) (which I freed from another MOC).

Digital version is at about 2400 parts so far. I actually expected it to be less.

 

[pagicence]

4 hours ago, Erik Leppen said:

Unfortunately though, the gray ball joint parts with half frames block the path to the rear row. This means that technically, riders can't enter the back row. But I think I leave it like this,

 

4 hours ago, Erik Leppen said:

One thing that is not realistic is that the gates open towards the queue. Normally, the gates open towards the walking direction.

Don't worry about things like that, just like you said:

4 hours ago, Erik Leppen said:

a Lego model as representing a thing instead of literally being it.

Plus your ride is far better than others so far.

[shadow_elenter]

On 7/29/2018 at 9:44 AM, Appie said:

PF switches are 7 bucks @ Lego

Yes,but then you get the new ones without the little black polarity switch... and that thing comes in very handy at times!

[Erik Leppen]

This topic had been quiet for a while, because I'm waiting for parts, but in the meantime I still have some progress. So here's the update on where I am now.

The most important thing is that it's now motorized, and the three motorized functions are functional.

I think the two most visible changes are

• The counterweights
• The stairs

To start with the first: I added weight bricks to the other ends of the swingarms. These really improve the balance, and make it possible for the motors to lift the bench. I put the weight bricks in typical counterweight-shaped black parts. Shame on me for using system bricks to enhance the looks on a Technic competition, but remember, the weight parts are actually functional elements :) The weight bricks (2 per side) are as much towards the ends of the arms as possible.

The second visible change is that it now has two stairs added on the sides so it's actually reachable from the floor. Probably if this were a real ride, the base would be sunk into the ground so the blue platform is flush with the floor, but I can't build below the ground in Lego :)

Also, I covered the holes in the towers with some tiles. I think that's all the decoration the towers will get.

Of course, the big functional change is the motorization.

I had attached motors to the turntable drive units, only to find out that they didn't work. Everything was slipping, because the turntable was driven by a bevel gear. I thought I had secured it tightly, but it still slipped. Also, the mechanism was too complex, so there was little power left to drive the actual functions. So I had to redo those sections. I drive the turntable ring with normal spur gears now, and made the drive train simple with as little friction as possible. The drive units are very strong and run smoothly, and the XL motors have plenty of force to drive the swingarms. But the motors are closer to the function, so the drivetrain is simpler. The modules are bigger than the old ones, especially the primary one, that houses two functions. The XL motor is on both sides, between the yellow beams of the tower and drives the swingarms. The L motor is only on the primary side and drives the bench rotation. The L motor hangs a little ugly there, but I'm afraid I have little options. There is not much room, and every additional gearing reduces the force left for the actual function.

So this gives 3 motorized functions. The other functions (entrances, gates and restraints) will remain manual, using the knobs at the front. (These wil probably be replaced by something in a bright color, such as orange.)

A slightly less visible change is that I reworked the central area to house a battery box. This required some additional reinforcement, but as a result, the whole black structure around the battery box is much stronger now and the frontal blue platform also feels much more rigid. (Also notice I changed the yellow railing to 16L links instead of 9 and 11 axles.

Currently, the three motorized functions are linked as follows: There is a IR receiver on each side (the one on the left is next to the remote); both IR receivers connect to 1 XL motor. They are on the same channel, so I can use a single remote for them. The L motor is connected via the polarity switch on the right (see the red axle sticking up). All those elements are fixed a bit sloppily to the frame for the time being. This is an intermediate solution so I can show the thing working on a meeting next week, provided I can use one RC channel. Two extra polarity switches are ordered. As soon as I receive these, I can rebuild things again and get rid of the RC solution. Basically, the three switches will form some sort of a control center. But given the short wires, the switches will be approximately in the same place where the IR receivers are now.

I notice that the wires are annoyingly short on all those elements, so it's all a tight fit. Maybe I have to raise the base and let wires run underneath.

One last chnge is that the white plates from previous builds has been replaced by dark gray, and the raisable floor is now built with studded bricks.

 

 

[pleegwat]

For short wires, there are extension cords you can order.

[Erik Leppen]

Yeah, I know extension cables exist, but I'd rather not order even more expensive parts. Also, I can imagine myself using those switches more often in the future, but extension cords are less likely, because I usually don't build super big.

Anyhow, I received the switch parts I bricklinked (I deliberately ordered them from a shop from my own country), so I have all the parts I need now. Two of the three switches have been installed (at the back, out of the way), and everything (except the third switch) is routed to a knob at the front. Currently the front has 5 knobs, and 1 missing.

• open/close entrance and restraint
• raise/lower movable floor
• battery on/off
• switch for the left swingarm
• switch for the right swingarm
• switch for the bench rotation (missing)

The control for the entrance is at the center. I moved the control for the moveable floor to the secondary side, to free up space on the primary side to put a switch for the final motor. That will probably be added tomorrow, bringing the total number of controls to 6, and then I will probably color-code the controls so it's easier to know what does what.

Also, I notice that this model uses a lot of long axles. Many more than my usual models. Fortunately I don't have a shortage yet.

Sorry, no photos this time, but the changes aren't very visual anyway.

[Erik Leppen]

I have finished the ride and added it to the Entry topic. So it's now officially done! :D

 

As you can see, I added the operator's panel at the front, using color coding for the various controls.

• Blue = platforms
• Red = gates/restraints
• Orange = battery on/off
• Medium azure = left and right swingarm (XL mptors)
• Lime = bench rotation (L motor)

 

Here are some additional pictures not in the entry:

I think it looks pretty impressive from a low standpoint

The black structure around the battery box has three pairs of 6x8x10 triangles for rigidity.

The obligatory underside picture. Note how the axles from the medium azure controls go all the awy to the back, where the switches are. The control for the platforms has moved to the left, to make room for the third switch (lime control). All the wires are just long enough to fit.

[Akbalder]

I really like this one! 

The way the the gate controls connect to the seats restraints is clever.

[RohanBeckett]

well done!  very authentic movements! 

and I love the mix of manual, and motorised controls.... really looks like it'd be a lot of fun to play with!

[BrickbyBrickTechnic]

That is so cool! Definitely my favorite so far, I love how you combined manual and power functions and how everything works so smoothly!