BMR-2
Model of a Spanish armoured personnel carrier. Features full independent suspension, 6×6 drive, 2-speed gearbox, remotely opener rear ramp, deployable tracked drone and lights.
Datasheet:
Completion date: 14/08/2011
Power: electric (Power Functions)
Dimensions: length 56 studs / width 29 studs / height 24 studs
Weight: 2.306 kg
Suspension: full independent
Propulsion: 1 x PF XL geared 6.5:1 (low gear) / 2.3:1 (high gear)
Motors: 1 x PF XL, 3 x PF Medium, 2 x micromotor
BMR-2 is a modern Spanish armoured personnel carrier. It’s a fairly typical vehicle for its class and I have chosen it mainly for its short chassis with first and last axles steered. I was hoping it would work well in an outdoor Truck Trial race. Unfortunately, it turned out that this kind of a steering system won’t work for a vehicle of that size, weight and with these tires without differentials. I haven’t been able to build it on time and therefore I abandoned plans to try it in a race.
The model had a full independent suspension that used 8297’s set components. Axles #1 and #3 were steered through a common steering shaft, by a Medium motor geared down 9:1, with a safety clutch. All wheels were driven by a single PF XL motor through a remotely controlled 2-speed linear gearbox.
The chassis was entirely studless, with majority of internal components located above the middle axle. The body consisted mainly of plates supported by a frame of Technic bricks. This solution resulted in an unusually low weight – something I was expecting and which prompted me to try using only one shock absorber per wheel. The suspension created this was was very soft, and even though it worked, the model displayed apparent tendency to ‘sit down’ on the third axle.
Close to the end of the building process I have realized that I can save up some internal space at the back of the model. It led me to realize an idea that followed me for a while (or was it planted?) – a small tracked drone deployed from inside. In a way, this was a MOC within a MOC, and thus: a MOCception 🙂 The drone was extremely simple, built around two micromotors with chains instead tracks. The micromotors were powered and controlled by two long wires connected to a separate IR receiver inside the transporter. The drone could be deployed once the rear ramp was opened and it could operate outside its carrier. It worked well, but due to its extremely low weight it was somewhat struggling against the wires. I have also integrated something like a simple passenger compartment into the upper hull’s surface, and it turned out to be perfectly fit for a single dwarf hamster.
Thank you!!!Good luck!!!
@Vadim
At Bricklink. This link is my every single video.
Hi !!!Where did you buy parts for tanks??Throw link,please!
@Antony
No, I’m afraid not. And XL motor is bad for steering.
any place where i can find the tutorial to the steering system WITHOUT having to buy your book? you see, i can not pay in credit card. im 15 >.>
anyway, will the steering work with a small or xl motor? i dont have a medium.
@nitwity
It’s a simple suspension, you can see it in my book.
Do you remember at least how to make the wheels drive and turn all at once, this is where I am lost *the back and front wheels can turn while driving*@Sariel
@nitwity
Sorry, but no, it’s not possible.
I hate to ask but can you either post building instructions for ONLY the chassis or at least a picture of the underneath and ontop of the chassis, Im trying to model this, I seriously want 1
@bob
I doubt it.
hey, do you think when i build your old chassis for this beast, and i replace the 8t gear in a 12t gear, it wil work wel in trtr?
@Cody
Yes, they do.
Sariel, I have the 9397 logging truck and I was wondering, do linear actuators and mini linear actuators have some sort of safety to prevent breakage from over extension?
@me
Here’s the instruction for the 8297 set, look through the rear axle’s design, it’s all there:
http://technic.lego.com/en-us/BuildingInstructions/8297%20Group.aspx
me again.
I want to build a big vehicle with big wheels and full suspended, I know you use special parts for that. What part(s) do you use? What type of suspention do you recommand(6,5L or 9,5L, hard spring, soft spring)?
@me
Here: http://www.bricklink.com/catalogItem.asp?P=44772c02
@Sariel
What is the item ID?
@me
Bricklink.
Where did you get those wheels? I’m searching for really big wheels but I can’t find them.
@David
Apparently not.
Why does it sit down on the back axle, aren`t most of the compoents on the middle axle?
@tom I hadn’t realized just how small the rear compartment was.
@shawn the goal wouldn’t be that it isn’t lego but that the drone is independent from the APC and this would prodably mean that it can’t be fully made of lego because some lego pieces are just larger then they actually need to be.
unimog wheels could be better 🙂
@tom I would think there’s no reason for a non-lego autonomous rover. Just use Mindstorms.
i like it very much but it would hve been so much cooler if the drone was completely independant from the APC . I know that to do such a thing the drone can’t be fully made of lego pieces but or maybe not at all lego but it still would havenlooked good (just my opinion )
@Mecho12345
They aren’t u-joints. You put u-joints inside them and they protect them from tensions that could damage them.
i dont have a facebook but i want to comment on your first post on the rg-35
what do the “Dark Bluish Gray Technic, Steering Ball Joint Large Receptacle” and “Light Bluish Gray Technic, Steering Ball Joint Large Open with C-Shape Pivot Frame” do? are they kind of like u-jointsor what
@MeCho123451
Plain and simple: no space for two.
why do you only ever use 1 xl motor? 2 would be much more powerful and you wouldn’t need so much gear reduction.
My TT had the same setup. The suspension was way too soft, and I didn’t want to spend much money on the big yellow shock absorbers from 8466. Turning radius was quite big, and the steering was too loose. If I tried to climb against a wall, it fell to 1 side, because of the rear steered axle. Link: http://www.flickr.com/photos/luc2000/sets/72157626503017948/with/5621327215/
pretty good. had to laugh at how the armor kept falling off. hope the rg 35 works welll
@Mecho12345
They were in 28 various sets. Here: http://www.bricklink.com/catalogItem.asp?P=5306bc162
I thought the wires were either home-made or from bricklink. What sets are they in?
@Robin
No, I can’t.
Hello Sariel,
I can not see video, because “Unfortunately, this viedeo, which includes music from SME, not available in Germany since the GEMA has the publishing rights are not given here.” could you also please the viedeo on another website and upload dan me write the link? sorry for the poor translator!
Robin from Germany
@jade2448
Well then, I guess the cost of pieces is under $1,000.
I realize that, just I was curious about it.
@TLT803
I’m using rechargeable NiMH AA batteries.
I’m sorry this is off topic, but what kind of batteries do you use with a regular PF battery box?
I ask because a NiMH rechargeable AA is 7g heavier than an alkaline AA. That means a box with NiMH batteries will be 42g heavier. I’m guessing that your MOCs are so strong it doesn’t matter much.
If you use NiMH the 8110 does tilt noticeably.
Beautiful model!
@jade2448
You do realize this is not a set and I’m not selling it?
how much do you think this is worth in the US?
Cool apc
@Mecho12345
The race is on August 20th, and as for wires – in how many places do I have to write BRICKLINK?
@shawn
Of course not, differentials are most needed in steered axles.
and when is the TrTr race?
1 meter long wires?!? where did you get those? anyway awesome mocception;)
Could you get away with using just one diff on the center axle?
@Spiller
There are some WIP photos at my Facebook page, with chassis for instance.
Any photos of the internals?
I happen to be doing something similar, a 6×6 with steering on the font and back axles. NXT project though, some RC programming I guess…
I wouldn’t feel very secure if the armor suddenly fells off though ; )
I also like the hamster seat and the mobile drone.