Tarix819

The tracks are made using individual Technic track links - in total seven pieces each. These tracks are a huge benefit to Tank-building as I can increase or decrease the width of the tracks from 3 to 12 studs as I please intead of being limited to the 4.5 stud width official Lego Technic Tracks. Another benefit they offer is that I have more choice in the size of sprocket wheel I use. Regular technic tracks are limited to size 3, 5 and 7 technic sprockets, however since these tracks use friction from Lego rubber tyres, my sprocket size is limited only by the sizes of Lego rubber tyres. That said, the tracks are very time-consuming to build and are quite heavy, boosting the overall weight of the vehicle even more. I did think about using an RC Battery pack, however I decided to be more 'purist' (Although i'm still using SBrick with this) and go for an unmodified Lego Battery Box. The only reason the vehicle has so much power is the type of Batteries used in the Battery Box.

If some of the images aren't showing up, here they are linked on Imgur: https://imgur.com/gallery/lLRkXIL Greetings all! Here is the post on my new Lego Technic model, which is of the British Second World War Cruiser Tank, A34 Comet: It entered production in late 1944 but didn't see proper service until early 1945. By Second World War standards it was an excellent vehicle, being fast, well armoured and equipped with a powerful QF 77mm HV gun capable of dealing with almost any enemy tank. It also saw action during the Korean War, however was shortly after superseded by the Centurion Main Battle Tank. The Korean war saw the introduction of the Comet Model B, with the large engine vents sticking out like a spoiler, as shown in the image below. My vehicle is of the Model A which was used during the Second World War, which is noticeably different as it lacks this 'spoiler'. Some information: Weight: 5.9kg (Making it possibly one of the heaviest Lego RC tanks on YouTube). Dimensions (mm): 290 width x 680 length (830 including the length of the main gun) x 300 height. Motors: Nine Power Functions Motors in total (2 XL, 2 L and 5 M) Driving is done by the two XL Motors alone. Fully functioning headlights and turret lamp. Traversing bow machine gun. 360-degree traversing turret. Elevating and depressing main gun. Shooting mechanism which fires projectiles through the barrel. Recoil mechanism for the main gun. Spent shell casing ejection system - dispenses through the floor at the rear of the turret for collection (Not enough room for a proper collecting tray). Powered by one PF 7.4v Li-Po Battery Pack in the turret, and one AAA Battery Box in the hull. The AAA Battery Box is equipped with three 3.7v 10440 Li-Ion Batteries and three AAA dummy batteries which when fully charged give the vehicle 11.1v of power, though they need to be recharged somewhat more often than a usual 6x 1.2/1.5v Battery Box would. This is how such a heavy vehicle can drive so quickly. Another benefit of this power set up is I could take the advantages of programming in the SBrick (Which is how the firing mechanism works), whilst achieving almost the same voltage as the BuWizz, without spending so much money. The firing mechanism is quite powerful, and the footage doesn't really do it justice (probably in part due to the quiet sound), though its power is somewhat reduced by the length of the barrel and the small space inside the turret, still it is a good deal more powerful than most Lego Tank firing mechanisms on YouTube. It alone is controlled by three M motors. Speaking of the firing mechanism, this is the sole reason the model is so big. My firing mechanism as you have read is very functional, however it is also quite large and I needed more space inside the turret for it, as well as the Li-Po, SBrick and Elevation/Depression mechanism, and on top of that, room for it to recoil. The Comet already has quite a large turret in comparison to its hull, if I decide to build tanks with smaller turrets, they would be to an even larger scale. The tank can only turn reliably on smooth surfaces due to its immense weight, however it is at least able to. Powered by two SBricks, one for the turret and one for the hull. A few last images: First photo of the in-development hull, I started work in early December 2019. Photo of the in-development turret, showing the mechanism and SBrick. Early photo of the turret married to the hull. Taken some time over Christmas. The placeholder three-cylinder tractor engine I had in the tank before I built one which looked more like the Rolls-Royce Meteor. I like my 'Expert Builder 1977-1980' style of Technic engines.The SBrick and Li-Po (Which was originally in the hull) can be clearly seen. Photo of myself next to the mid-development vehicle. The thing is huge and a pain to carry around. The vehicle at about 90% completion. The vehicle compared to the 8865 Test Car, showing the huge scale of the model. The almost completed vehicle compared to the size of a mug. Prior to some last suspension changes, though the front fenders have been improved. Thanks for reading.

I wish BuWizz would introduce a version without the Bluetooth functionality for a cheaper price so it could be used with SBrick as just a better version of the 8878; the SBrick providing its better range and Profile Designer system, and the BuWizz providing the increased voltage.

Hi, I have a model which is currently driven by 4 PF XL motors working together. I only have one Sbrick to drive the vehicle but it needs to have 4 XL motors to drive it, no less. Unfortunately the safety fuse likes to activate a lot when driving which stops the vehicle completely because it doesn't like the 4 XL motors working simultaneously. My question is: Is there any way around this without purchasing another Sbrick? I have looked online at solutions and apparently linking two battery boxes to the one Sbrick using the 2x8 electric plate would work, and it's certainly a much cheaper option but I have never tried it. I am also aware that the Sbrick has a voltage limit of 11.8v so i'm a bit concerned that using that method might fry my Sbrick, but have no idea if this would happen or not. If I could get some advice, that would be really helpful, Thanks,

Extremely unlikely to be a subtractor. The model is way too big and Lego diffs don't cope well with high torque. It doesn't matter though, as the the control will likely be similar to sbrick, where each track can be controlled by a slider, providing the same function a subtractor would. Subtractors in tracked vehicles are pretty obsolete nowadays unless you're stuck with the basic IR receiver and regular controller.

I am so excited for these new sprocket wheels. Previously the maximum size you could get is the 5 stud diameter sprockets which are too small for vehicles like some tank variants. For tanks with large sprockets you had to make compromises. With these new sprockets (which will hopefully come in black or grey at some point) it'll be easier to build tanks with larger sprockets such as the British A1E1 Independent or Soviet T-28 at larger scales.

-Some car chassis so builders can modify them easily and build their own bodies for them - Technic parts and motor packs - the 8293 is pretty lackluster, there should be Servo motor/XL motor/L motor packs with differential gears, driving rings and other specialised parts to boost our technic capacities (Maybe with new 10v/12v battery boxes aswell?)

IMHO Colour Vomit is one of the major downsides with Technic Lego - it makes Technic models look awful and unrealistic. I understand that Lego wants to make sets easier to build but if you can't distinguish between a pin and an axle without the help of colour difference then you shouldn't be buying Technic at all. Besides, I thought Technic was supposed to give people a challenge? I remember when I was younger refusing to let my parents help me build Technic sets because I stood by the doctrine of DIY - 'Do It Yourself'.

Very cool, I like it!

Thanks for the advice, I will do a bit of thinking and then decide. SBrick looks more promising at the moment.

I'm thinking of getting a Lego device that will give my models more power and allow me to control them outside and from long distance using my smartphone. As far as I am aware the best two options are BuWizz and SBrick, however I am not sure which option is best, as comparisons I have seen have never determined a clear winner. SBrick is way more affordable, more compact and seems to be popular in the Lego Technic community. I only learnt about BuWizz recently, it seems to generate an insane amount of power but it costs over twice as much as an SBrick and is bulkier, plus I already have 6 Battery Boxes and it would be a complete waste not using them. Of course they are both clearly better than the Official Lego PF IR Sensors I am currently using, which are god awful past a 2m range and are useless outside, however I would like to know people's thoughts, opinions and experiences to help me decide which is best value for money before I blow loads of cash on a toy. Currently I am leaning towards SBrick, but from what I've seen online, BuWizz looks like a viable option also. Cheers

Servo Motors are quite expensive (Cheapest I could find is £23 on BL), you might be better off using an M-Motor and a clutch gear instead for steering.

It is not actually the gearbox that breaks. The 1:1 ratio is on the drivetrain before the gearbox. It is the only gearing between the motor and the gearbox. But thanks I will try what you said anyway.

I have loads of motors so availability isn't a problem. When I use an XL motor, a 1:1 gear ratio of two old-style 16-tooth gears breaks, which I have strengthened as best as I can. Thank you I will try that

Do you think adding a second L-Motor, gearing the drivetrain down and then gearing it up again just before the differential would work?

Problem is I want it to go fast but gearing it down whilst will improve the torque will reduce the speed.

Just tried it and no, it still remains stationary even if powered directly from the battery box. (Which is a LiPo btw).

I've tried both gearing up on the move and moving from stationary in 3rd gear and it has the same effect. The wheels are very large, they are the classic foam tyre wheels found on the 8865 Test Car, 8860 Auto Chassis and 853 Auto Chassis.

It comes from Sariel's book: 'The Unofficial Lego Technic Builder's Guide' I think.

My vehicle has 3 gears: 1st gear: 1:3 2nd gear: 1:1 3rd gear: 3:1 At the end of the drivetrain a 20-tooth gear connects to a 28-tooth differential with the ratio 1:1.4. In first gear the vehicle drives fine, the second gear the vehicle drives fine, however in third gear the vehicle will not move unless travelling down a slope. When I add more motors or use an XL motor (Instead of the single L motor I am currently using) the drivetrain simply breaks. The vehicle weighs about 1.4kg. Also keep in mind for changing gear I am not using driving rings, I am using a linear gear system similar to that of the 8860 Auto Chassis model.

I think I should be okay since I only want to power 2 L-Motors which, assuming the V1 Receiver allows 800mA, should be fine as L-Motors are about 300-400mA each.

Thanks!

Unfortunately I don't own any V2 IR Receivers. I understand that they allow two motors to run at full power whilst connected to the same port? If I use 2 regular V1 IR Receivers and connect one motor to each will it achieve the same effect as 1 V2 IR Receiver?

Thanks very much for the quick responses, that clears it up nicely. I think the biggest problem I'm having is the complex drivetrain, which is using the old linear gear changing system (no driving rings) and is constructed mostly of the old 1970 - 1990 lego technic, so I will look for some ways to make it more resistant to high torque. Thanks!

Hi, new here! I am a big fan of building Lego Technic RC cars but have a few (probably stupid) questions: When hardcoupling two motors, is a separate battery box required for each motor to improve the mechanical power? If I only use one battery box to drive both motors does is the power split between them? What are some ways of reducing stress on a drivetrain to prevent gears from slipping and grinding? Thanks, Nick