[TC25] 8109 Flatbed Truck

[SaperPL]

1 hour ago, TechnicMOCer said:

Looks very cool with almost proper colors already - looks actually like original set.

 

51 minutes ago, NoEXIST said:

Actually like this little truck! You made a good job replicating the original set!

Thanks! The last two challenges are the sides of the cab that are now in red, where I'm not sure whether to go after yellow connectors like this and call it a day with liftarm 1 in yellow in the gaps, or whether to try using some panels or liftarms there. Noteworthy is that the doors end behind the seat which means that I either could try making the fake battery thinner and move the seats back one stud, or try to fill that one liftarm thickness at the edge of the door, but opening the doors would mean having them cut into that edge.

Btw, I've got the sheet of stickers for 8109, will have to cut them down to size, but only after all colored parts are there. I also solved the roof headlights:

And that's a really tricky assembly to hold that black liftarm there:

Not ideally same as in original as those will be spread apart, but I rather have something solid than loosely put together.

1 hour ago, TechnicMOCer said:

I ordered some parts recently for Unimog and future projects, so I know what you feel 😬.

 

1 hour ago, NoEXIST said:

I hope it worth it:)

My guesstimate now is that the *new* parts for this MOC might get to around 75 EUR or maybe more. The part that annoys me is that our local marketplace is really quick to get the parts in comparison to getting them from Lego and also I feel like I'm in better control to know what I've already ordered then when I went with pick-a-brick from Lego. But each order has some markup and separate shipping fees and it's about figuring out how to optimise what to get from whom. And those last few pieces right now look like I might be getting few pieces from one reseller and paying that extra for shipping. Custom MOCs in pefect colors are expensive :|

[NoEXIST]

28 minutes ago, SaperPL said:

 

Thanks! The last two challenges are the sides of the cab that are now in red, where I'm not sure whether to go after yellow connectors like this and call it a day with liftarm 1 in yellow in the gaps, or whether to try using some panels or liftarms there. Noteworthy is that the doors end behind the seat which means that I either could try making the fake battery thinner and move the seats back one stud, or try to fill that one liftarm thickness at the edge of the door, but opening the doors would mean having them cut into that edge.

I think that if you use liftarms mixed with connectors it will look discontinuous, while a connector assembly looks more consistent

[MP LEGO Technic creations]

8 hours ago, SaperPL said:

liftarm 1 in yellow in the gaps

I'm not really sure that 1L liftarm exists in yellow, though I could've missed some recent release. It's a shame because any other parts (like yellow bushes) will spoil the looks with additional gaps...

Otherwise the truck looks great!

[SaperPL]

1 hour ago, MP LEGO Technic creations said:

I'm not really sure that 1L liftarm exists in yellow, though I could've missed some recent release. It's a shame because any other parts (like yellow bushes) will spoil the looks with additional gaps.

Yeah, I went ahead of myself there with this 1L liftarm, forgetting that I put it there as a placeholder for the looks. So still I have to figure something out here on how to assemble this area.

1 hour ago, MP LEGO Technic creations said:

Otherwise the truck looks great!

Thanks! It'll get even better :)

10 hours ago, NoEXIST said:

I think that if you use liftarms mixed with connectors it will look discontinuous, while a connector assembly looks more consistent

I was thinking about something like this:

But the problems are plenty: doors are opening below this black bar, it hangs on just that single point of attachment to the panel and on the other side I need to put the axle through for the platform operation.

Edited July 20, 2023 by SaperPL

[NoEXIST]

49 minutes ago, SaperPL said:

But the problems are plenty: doors are opening below this black bar, it hangs on just that single point of attachment to the panel and on the other side I need to put the axle through for the platform operation.

Oh, I thought construction requires some pin connections in there... It's a good idea then. The door is interesting point, because it isn't openable in the set and they made longer cab than you wait to see on a tow truck. 

 

If we talk about proportions and seat position, it seems okay, but the door may be a little shorter. But I can say nothing about it because I don't know much about yellow panels😅

[SaperPL]

3 hours ago, NoEXIST said:

Oh, I thought construction requires some pin connections in there...

I need to hold the roof onto something, but I should be able to attach it to the fake battery structure as well. The problems are there needs to be a hole on the other side for the axle with input for platform elevation, so actually I cannot have this lowest panel there. But I could try and think about moving the input for that to the roof if I could achieve perfect looks on the sides here.

The bigger annoyance however is that holding this whole assemble just by a single axle attachment and still figuring out then how to add that black axle connector to the fake battery assembly.

[SaperPL]

Got some of the parts missing for the front and decided how to tackle the sides of the cab. Still waiting for few pieces like the roof edges to be in yellow and some grey frictionless pins for the rear wheels.

I am considering using white portion of the sticker sheet to mask out the portion of red plates under the trans clear headlight tiles, but I'm not sure if this is okay. Similar technique was used already in some speed champions where they had stickers behind the trans clear headlights, but not on the stud itself, just on flat surfaces and I would be doing it on a stud that is actually forming a connection. Also not sure how okay is this to use sticker sheet this way, may be a gray area here.

I added rubber band to the winch lock as it makes more sense this way. I don't get why the original model didn't have anything like that apart from the fact that the way I did it is tricky to do.

Interesting thing is that I might need to change the frictionless pins in the wheel kneeling mechanism to the ones with friction as the wheels are kind of loose and when the platform is raised, the effect of wheels moving off the ground is not as pronounced as in the original model and as it was with blue 3L pins.

I will start tackling stickers once I'm sure I'm done with the model. I'm not sure how to tackle the sticker for the curved side panel as the original was a bigger panel and cutting away a portion of it means I need two ideally cut matching pieces to not be too noticeable that it's not a single piece. When it would be on two separate bricks, it'd be okay to just split it like Lego does it, but on a single one it'll feel messy.

Also any ideas for a simple corresponding car model to be towed/pulled onto the platform? Was there a set model that would ideally fit onto 8109?

[TechnicMOCer]

It looks better and better. I have only question for rear wheels - what about using 3L brown axles and wheels with axle holes on rear axles? That solution would be stronger than frictionless pins. Also you can use some panels/1x2 liftarms in yellow on side behind door - with these connectors looks a bit weird. For the car that you can tow, is one of 8-wide Speed Champions ones, that would look pretty cool.

[SaperPL]

42 minutes ago, TechnicMOCer said:

It looks better and better.

Thanks, I couldn't wait with the stickers since I'm not getting last pieces today, so I went ahead with cutting and applying them:

44 minutes ago, TechnicMOCer said:

I have only question for rear wheels - what about using 3L brown axles and wheels with axle holes on rear axles? That solution would be stronger than frictionless pins.

But it's not just the axles for wheels but whole mechanism holding the wheels is right now on frictionless pins as I wanted to see if this would affect the actuation/make the resistance lesser on the knob turning as well as I feel that should be the proper way to use frictionless pins for moving connections.

47 minutes ago, TechnicMOCer said:

Also you can use some panels/1x2 liftarms in yellow on side behind door - with these connectors looks a bit weird.

But I need this kind of connection there because I need to put this axle for platform actuation through it. It's complicated because of that, but the approach to have input on the roof feels wrong.

49 minutes ago, TechnicMOCer said:

For the car that you can tow, is one of 8-wide Speed Champions ones, that would look pretty cool.

My point was to potentially pick up another Technic set of a car that is around 15 studs wide that I would scale down to 75% to match this platform.

[TechnicMOCer]

5 hours ago, SaperPL said:

My point was to potentially pick up another Technic set of a car that is around 15 studs wide that I would scale down to 75% to match this platform.

I think 42093 or 42151 would be the best approach.

5 hours ago, SaperPL said:

But it's not just the axles for wheels but whole mechanism holding the wheels is right now on frictionless pins as I wanted to see if this would affect the actuation/make the resistance lesser on the knob turning as well as I feel that should be the proper way to use frictionless pins for moving connections.

So using axle with stop 5L or 4L (depends on how long is required), I think would work without any issues since wheels would prevent sliding them.

5 hours ago, SaperPL said:

Thanks, I couldn't wait with the stickers since I'm not getting last pieces today, so I went ahead with cutting and applying them

I love how it looks with stickers applied, totally like 8109. Maybe the front uses too much system pieces (at least for me), but original set has front made out of system.

[1gor]

For someone who makes tiny models I have expected that you will install all functionalities in smallest possible model. So honestly it is not a big surprize at all, but again you made great model.

[SaperPL]

21 minutes ago, 1gor said:

For someone who makes tiny models I have expected that you will install all functionalities in smallest possible model. So honestly it is not a big surprize at all, but again you made great model.

Thanks, and yeah, I chose this size estimating to be able to make it in reasonable quality at this scale. Just from my experience, going below 11 wide/7wide between the wheels starts complicating things and that is why I didn't want to go smaller than this. So exactly smallest possible.

By the way interesting case of this contest is the fact that we are forced to change motorized features into manual ones, but where is the line we draw when making something manual.

I think that I noted that few times when talking about knuckle boom cranes and excavators, but if you're not routing all inputs to the back of the model/to one place for controls, using knobs at each segment kind of defeats the purpose, and instead we could just have segments manually adjusted without additional knobs, just through those system click joints. And because of that, since it got impossible for me to make the towbar rotation driven in any reasonable way, so I had to do this part manually anyway, It didn't make sense to make the extension driven with a second linear actuator, despite the fact that I managed to fit it in the construction and shown that it's possible.

I wonder how will the competition look at the end of run because there's still a month for them to participate and we could see some late runners joining the game next week for example, and there's already quite a few interesting submissions.

Btw2: I was considering shrinking the 42000 (Grand Prix Racer/F1 Race Car) since I could have enough white panels to build it, but it's not the kind of tow truck for the F1 race cars and it wouldn't climb the ramp with his front spoiler. So I started figuring out whether maybe I can shrink the 8081:

It's kind of doable, but once I make the steering active, it causes problems when pulling it upwards with the winch, so need additional mechanism so steering doesn't move loosely.

Second part is that actually the hook needs more than 1L of space , so having liftarms next to the axle it's supposed too hook on makes it impossible for the hook to go around completely. So whole attachment of the front bumper for hooking got too complicated with steering around and need to shift it by half stud vertically.

[1gor]

I agree that making lots of things in small space is very challenging; even for me (my models are in 1:15 scale) it is hardto implement what I want and have sturdy model because everything has a kind of chain reaction.

[Appie]

55 minutes ago, SaperPL said:

And because of that, since it got impossible for me to make the towbar rotation driven in any reasonable way, so I had to do this part manually anyway, It didn't make sense to make the extension driven with a second linear actuator, despite the fact that I managed to fit it in the construction and shown that it's possible. 

Have you considered a well placed rubber band forcing it to be folded by default and a well placed rope making it fold out when extending the towbar? Similar to the mechanism of its big brother, but without the gears. I Have no idea how much space you'd have for it and I assume you already looked into it, but a suggestion none the less.

[SaperPL]

25 minutes ago, Appie said:

Have you considered a well placed rubber band forcing it to be folded by default and a well placed rope making it fold out when extending the towbar? Similar to the mechanism of its big brother, but without the gears. I Have no idea how much space you'd have for it and I assume you already looked into it, but a suggestion none the less.

Yeah, I was thinking about using the rope for that, but the complication is that it should start pulling on the towbar to rotate it with a delay. And there's literally no space to play with such things, there's 1 stud horizontally and 2 studs vertically for most of the length of tow bar extension arm, and there's a bit of space on the sides between the wheels, but that's it:

Note that I have to do some shenanigans with attachment of the red axle on which the tow bar assembly is sliding because in the spot where I need the axle to be attached, the platform raising levers moved by the actuator are passing on the sides (the two black pin-axle connectors angling whole thing to move around the linear actuator), and more to the back, I don't have option to attach anything on the sides of this because the mechanism could get stuck.

The problem with the rope approach is that unless it's perfectly guided in the middle, it could get stuck when the platform raising mechanism is working, and apart from this, I would have to figure out a way for it to only start pulling once the towbar is out of the headlight's clearance, and such mechanism means some controlled slack and it means having space for it.

Also the problem with rope (the one with ends in round plates) is that not all ropes are perfectly equal and they get stretched over use and thus for a model with instructions this could make this function not work correctly just because someone has a rope that is slightly longer. And also for the twine having perfect length required would also be a problem to perfectly tie knots etc.

[NoEXIST]

On 7/22/2023 at 4:19 PM, SaperPL said:

Thanks, I couldn't wait with the stickers since I'm not getting last pieces today, so I went ahead with cutting and applying them:

 

So all the stickers are from that original set sheet? That's cool you was able to use them in the model with smaller scale!

[Appie]

I wouldn't worry too much about ropes stretching or not and the studded ropes not being perfectly equal.

So the area left and right of the LBG 11L flip-flop beam is available space? That 1L in height. I see some options for a rope with slack, but the rubber band is another story since where I'd want to put it, it collides with the 11L red liftarm from the rearlights

[SaperPL]

5 hours ago, NoEXIST said:

So all the stickers are from that original set sheet? That's cool you was able to use them in the model with smaller scale!

The black bars on the mirrors are leftovers from mobile crane set because apart from the Technic sticker in the middle, this sticker sheet didn't have much black:

Note that I don't have place for attaching the functions information to make sense, and more importantly the sticker for big curved panel would end up depicting tiny hatch in the middle of the panel if I were to cut it in the middle to shrink it to this size of panel, and then I'd have to figure out how to fit it together with Road Service text and the stripe. I just managed to fit Road Service text and the stripe there (it's not on the photos yet, I fixed it a bit later).

6 hours ago, Appie said:

I wouldn't worry too much about ropes stretching or not and the studded ropes not being perfectly equal.

For the contest maybe, but for instruction if the function doesn't work correctly because of that, it's a problem.

6 hours ago, Appie said:

So the area left and right of the LBG 11L flip-flop beam is available space? That 1L in height.

Yes, but only at the same height something can be attached to the 15L LBG beams, above it everything is moving.

6 hours ago, Appie said:

I see some options for a rope with slack, but the rubber band is another story since where I'd want to put it, it collides with the 11L red liftarm from the rearlights

But rope with slack needs the slack to be handled somehow, otherwise when closing the slack will be loose anywhere, even next to the end.

And yeah, I had the rubber band there and it worked, but it did push whole thing like 1/5 of the stud away from the liftarm holding the lights.

[SaperPL]

Got the last missing parts, replaced frictionless pins with normal ones for the back axles and captured some footage to show you how the kneeling mechanism works:

You can also see here how I fixed the sticker with the name and the stripes on the right of it.

Also managed to do 360's:

 

Edited July 24, 2023 by SaperPL

[Appie]

That looks absolutely awesome

11 hours ago, SaperPL said:

Yes, but only at the same height something can be attached to the 15L LBG beams, above it everything is moving.

Ok, another idea, involving no ropes or extra space used (yet) even. I am assuming you have no desire to have the towbar and the bed work at the same time, since they would collide anyway. How about having that axle with the 2x #3 connectors (which I assume are there to guide the mini-LA upwwards) have the assembly of the towbar push back, but have the axle go through the 11L red liftarm holding the rearlights, pushing against the 2L perpendicular connector. This connector is held in its folding/resting place by a rubberband. Path of least resistance should cause it to extend first and then push out the towbar. Only leaves the problem of making that 90 degrees flip a 180 degrees flip

Edited July 24, 2023 by Appie

[SaperPL]

1 hour ago, Appie said:

Only leaves the problem of making that 90 degrees flip a 180 degrees flip

Double it by figuring out how to make sure it rolls back those 180 degrees when you are pulling it. That's a complex problem and the way they did in it the original model is a good one and there needs to be some proper way of handling the slack and I don't see a place where I could do this properly except if I were to rebuild whole cab and have the string and linear actuator control for it somewhere there together and some kind of slack control there, but I already had hard time with steering and platform actuation. Also if I were to push out this axle there, the axle would be there above the towbar as well affecting the placement of a vehicle on it.

[Appie]

Made a little moc-up in Studio. How about a rope through the blue thin 2L liftarms? Each side a seperate knot on the rope, which runs back to the towbar from underneath. Once it reaches the red 1L liftarms (for which I extended your pin with axle to a 3L pin with axle) it would flip the towbar. The thing could be slightly angled towards the red liftarms when the towbar is in resting position, should still flip if not too far angled. This should make it require no slack on the rope, since that part simply goes later in the mechanism and first when sliding back. Obviously, combined with a rubber band to make the folded position the default one. I am aware that in this moc-up that 8L red axle would be sticking out at the rear, but that construction of how you want to slide it out and brace it, is up to you. I'd need to build the whole thing to figure out the wiggle room I have or don't have in that area I'd even consider putting something else in place of the flip-flop beam if it would help, but I can't make that assesment at the moment. I am also aware this 3L axle on the #3 connector might collide with the liftarms connected to the mini-LA from the bed tilt, I don't know the wiggle room for it. It seems the bed is already on the floor before the mini-LA is fully extended?

Edited July 24, 2023 by Appie

[SaperPL]

6 minutes ago, Appie said:

Made a little moc-up in Studio. How about a rope through the blue thin 2L liftarms? Each side a seperate knot on the rope, which runs back to the towbar from underneath. Once it reaches the red 1L liftarms (for which I extended your pin with axle to a 3L pin with axle) it would flip the towbar. The thing could be slightly angled towards the red liftarms when the towbar is in resting position, should still flip if not too far angled. This should make it require no slack on the rope, since that part simply goes later in the mechanism and first when sliding back with. Obviously, combined with a rubber band to make the folded position the default one. I am aware that in this moc-up that 8L red axle would be sticking out at the rear, but that construction of how you want to slide it out and brace it, is up to you. I'd need to build the whole thing to figure out the wiggle room I have or don't have in that area I.d even consider putting something else in place of the flip-flop beam if it would help, but I can't make that assesment at the moment.

1. Right now those black connectors are not moving, but the flip-flop beam is riding on the red axle there and the axle ends in the liftarm holding the rear lights. So if I were to accept that the red axle would be sticking out, I'd have to have attachment point on the other side of those black connectors where connected axle would have to travel and that gets complicated because this weird connection is there specifically because in resting position the linear actuator is intruding in to the bottom layer of liftarms. That's why I made this construction and trust me that those axles are not parallel to the liftarms because of that. If I were to make an attachment point, the platform wouldn't fully close down.
2. In a place where you've placed the 3L axle holding those blue 2L liftarms, I cannot connect anything there because the lever raising the platform intruding from the sides. It means that every time the platform would reach the full extension, it would pop out the tow bar a litttle at the back.
3. Those 3x5 L-beams are moving as shown in the gif above and attaching a rope in a way it won't get stuck between those gets complicated
4. How do you convert <90 degree pull on those bushes on the axle with blue 2L liftarms into 180 degree turn on the towbar?

Try to build such prototype anyway. I wonder how it'll actually work. The biggest problem here is actually the #4 on figuring out 90 degrees to 180 degrees with a rope.

[Appie]

1. Accepting a red axle sticking out or not is up to you. I wouldn't, but I don't know how much alternatives are in that space. As I said, if you are up for making that connector axle moveable this would be an option to have it remote controlled.

2. Yeah, I edited that to my earlier reply, but you already started a reply it seems Could try to add a brace somewhere so the mini-LA or liftarms don't go further, but that's under assumption it doesn't need to go that far to reach the ground. If it needs more, than that 3L axle won't work ever and that would pretty much toss my whole moc-up out of the window with the current chassis.

3. Depends on the routing at the towbar imo. Straight to the center 2L connector, yeah that will fumble on those 3x5 liftarms. Guide them in a straight line from 2L thin blue liftarm, to towbar and then to 2L connector (or just stop at the straight to towbar) should be no problem.

4. As I said, you could make the angle slightly bigger than 90 degrees by having them face towards the red 1L liftarms in the towbar folded position. Other than that, you could mess a little bit with where you knot you ropes on the liftarms to get a 2L flip to a 1L flip.

I don't have my Lego ready to build a prototype, hence the Studio image

Edited July 24, 2023 by Appie

[SaperPL]

I finally managed some time to shoot and clean photos for the entry:

 Full Size Photo Original Model

 Full Size Photo Original Model

 Full Size Photo Original Model

 Full Size Photo

Also updated the opening post with them. Now I need to put together a showcase video before I'll be able to submit the contest entry.

On 7/24/2023 at 8:55 PM, Appie said:

1. Accepting a red axle sticking out or not is up to you. I wouldn't, but I don't know how much alternatives are in that space. As I said, if you are up for making that connector axle moveable this would be an option to have it remote controlled.

2. Yeah, I edited that to my earlier reply, but you already started a reply it seems Could try to add a brace somewhere so the mini-LA or liftarms don't go further, but that's under assumption it doesn't need to go that far to reach the ground. If it needs more, than that 3L axle won't work ever and that would pretty much toss my whole moc-up out of the window with the current chassis.

3. Depends on the routing at the towbar imo. Straight to the center 2L connector, yeah that will fumble on those 3x5 liftarms. Guide them in a straight line from 2L thin blue liftarm, to towbar and then to 2L connector (or just stop at the straight to towbar) should be no problem.

4. As I said, you could make the angle slightly bigger than 90 degrees by having them face towards the red 1L liftarms in the towbar folded position. Other than that, you could mess a little bit with where you knot you ropes on the liftarms to get a 2L flip to a 1L flip.

I don't have my Lego ready to build a prototype, hence the Studio image

I'm short on free time to build recently so I don't want to start figuring out whole thing from scratch, and I would need to, really.

The first problem is that if I were to add second linear actuator, then the input for both linear actuators need to be handled and it would change the construction back to what I initially planned with two knobs where the access panel for gearbox switch is in the original model, and this is a place where turning the knob is not really ergonomic as well as the access panel tilting causes additional significant complications because it needs a clearance on the inside, which affects rigidity of the frame. It would be doable, but it would be a messy build and in the end using the knobs would be annoyingly non-ergonomic.

The second problem is that small linear actuator has barely any extension on its own, it's just 3 studs. This is visible on my gif on the first page where I actually tested it. It's enough to open up the tray, but not enough to actually tow a car with clearance like in the original model - note that in original model when the tow bar end starts rotating the whole thing is still moving laterally out.

It's just that even if I solved the problem of how to make it turn those 180 degrees back and forth, I would still have two big problems to solve here and I feel like both are not doable at the same time.

I could have more room internally if I cheated and used 1 stud wide wheels, but the original model had wide ones, so the ones that I picked are matching. But then it'd again get a bit complicated with steering at the front because of gear rack size requirement.