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Hey all, I've been pondering about this a lot lately. Ever since I built my Lamborghini Sian a few weeks ago, I've been tempted by RC'ing it (I apologize in advance to all the purists here who would rather keep it as-is) but I personally like to make my Technic stuff move. The Lambo though, I want it to be a little bit more special; I want it to be quick

I've been thinking to get Buwizz, not only for the Lambo, but in general for my MOCs, since it would have so many applications. My question is, will it actually make it faster than say hooking up two XL's to a normal PF battery back. I ask because all in, it's $250 CAD, which is quite a bit of money for a tiny box (one that does a lot of cool things, but still, that's a set right there). 

A quick search on Youtube found a couple of videos of Sians with Buwizz, but I wouldn't exactly call them quick. 

Maybe I'm just dreaming... the Lambo is a very heavy set, so perhaps it's not realistic to make it go as fast as I hope. Have any of you tried it on such a heavy Lego vehicle? Is it worth the investment? Any suggestions would be most welcome :) 

 

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To be honest: The Lamborghini is not built to be fast.

In this video you see a MOC of a Tesla with problably a similar or only slightly less weight. It is powered with two BuWizz and eight (!) L-Motors (and of course a Servo Motor for steering).

https://www.youtube.com/watch?v=BkVL4imQ5mM

Is that "fast" in your eyes?

 

 

 

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Funny thing is, that Tesla would probably be just as fast if not faster with four motors instead of eight. You get to a point where the added torque isn't needed and the extra motors just become dead weight.

Edited by suffocation

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1 minute ago, suffocation said:

Funny thing is, that Tesla would probably be just as fast if not faster with four motors instead of eight. You get to a point where the added torque isn't needed and the extra motors just become dead weight.

Kind of what I was thinking. Also why, if I end up getting the BuWizz, I'd just use two XL motors. I guess the only other thing I'd have to worry about at that point is the gearing. I doubt I'd get much speed if I bolt the XLs straight onto the main driveline axle. 

Edited by moebiusfactor

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I'd go with two L motors per axle, four in all. That should ensure more than enough torque and speed, especially in ludicrous mode. Furthermore, L motors are great for structural reinforcement, so you could easily gut out most of the car's innards without compromising its stiffness.

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Just now, suffocation said:

I'd go with two L motors per axle, four in all. That should ensure more than enough torque and speed, especially in ludicrous mode. Furthermore, L motors are great for structural reinforcement, so you could easily gut out most of the car's innards without compromising its stiffness.

That's a very interesting idea... and of course I'd still need BuWizz for this, right? 

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Just now, suffocation said:

For maximum speed yes, you'd need BuWizz. Two units would probably be better than one.

Thanks, this is good to know.

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1 hour ago, suffocation said:

Funny thing is, that Tesla would probably be just as fast if not faster with four motors instead of eight. You get to a point where the added torque isn't needed and the extra motors just become dead weight.

That's possible. I habe built the Tesla because I like the shape, but without the electronics. At least 360€ only for that is way to expensive ...

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This is the speed you can achieve with 2 buggy motors and 2 BuWizz units in a car that has approx. half the weight of the Sián. I don't think the 1:8 LEGO supercars can achieve a speed that they'd deserve based on the size and the look. Maybe if you remove the complete interior and squeeze in 4 buggy motors and 4 BuWizz units :D 

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@kbalage now that is quick ;)

I think if I wanted to RC a big heavy car to go quickly, I'd try to build @Madoca 1977's Icarus drive unit in there. It's an amazingly efficient way of getting 4*L motors to power an axle, and increasing the speed 3 times before it gets to the differential.

Two buwizz will give the maximum current those motors can draw. One won't quite do that.

If you aren't a purist, there are some new Chinese motors which give around 30% extra power over Lego motors. These will help your cause. They also draw more current and you'd definitely need the pair of buwizz for them. They also have 1,400rpm L motors, with which you could run the Icarus drive train with 1:1 gearing instead of 3:1, to increase speed and reduce torque in the drivetrain.

Or use those high speed L motors and the new planetary hubs. These are stronger than the old hubs, and again when you increase the speed you decrease the torque.

NB: All above, not for purists. 

Edited by amorti

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2 hours ago, kbalage said:

This is the speed you can achieve with 2 buggy motors and 2 BuWizz units in a car that has approx. half the weight of the Sián. I don't think the 1:8 LEGO supercars can achieve a speed that they'd deserve based on the size and the look. Maybe if you remove the complete interior and squeeze in 4 buggy motors and 4 BuWizz units :D 

Whoa that is quick! At around $200 CAD/each four BuWizz units might get pricey, but it IS a very tempting setup :devil_laugh: I almost wish I had a second Sian to experiment with! 

1 hour ago, amorti said:

@kbalage now that is quick ;)

I think if I wanted to RC a big heavy car to go quickly, I'd try to build @Madoca 1977's Icarus drive unit in there. It's an amazingly efficient way of getting 4*L motors to power an axle, and increasing the speed 3 times before it gets to the differential.

Two buwizz will give the maximum current those motors can draw. One won't quite do that.

If you aren't a purist, there are some new Chinese motors which give around 30% extra power over Lego motors. These will help your cause. They also draw more current and you'd definitely need the pair of buwizz for them. They also have 1,400rpm L motors, with which you could run the Icarus drive train with 1:1 gearing instead of 3:1, to increase speed and reduce torque in the drivetrain.

Or use those high speed L motors and the new planetary hubs. These are stronger than the old hubs, and again when you increase the speed you decrease the torque.

NB: All above, not for purists. 

Madoca's stuff is truly mind blowing; indeed, the way he compacts and takes every bit of power out of L motors is just masterful. I'll check out the Icarus for sure. 

I was looking at the Chinese knockoff motors as the actual Lego ones are crazy expensive; I do have one from an old, old set, but one won't do if I end up going down that route. I might consider those more seriously now though. 

Either way, I imagine if I want speed, regular PF components (besides the motors) just won't cut it. I initially thought about putting in 2 XLs with a single battery box, but it'll probably be super sluggish. 

Thank you all for the suggestions and ideas, this is great!! :grin:

Edited by moebiusfactor

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16 hours ago, moebiusfactor said:

Madoca's stuff is truly mind blowing; indeed, the way he compacts and takes every bit of power out of L motors is just masterful. I'll check out the Icarus for sure. 

I can vouch for this setup. I used Madoca's Icarus drivetrain in the Koncept Mantis, which is comparable in size with the Sian. (Acceleration video and size comparison can be found if you follow the link.) The Mantis is pretty light though! Definitely you'll want to get rid of the gearbox and fake engine of the Sian. It may not be so simple because the Sian is not a very modular build. In contrast, the Pimped Porsche cleanly separates the chassis and bodywork. So what I once did was build the bodywork as per the Pimped Porsche instructions, and then built my own chassis -- with the correct dimensions and connection points -- but with the Icarus drivetrain and no gearbox or engine.

800x600.jpg

The bodywork fitted neatly on top:

800x600.jpg

Now you'll want to know the performance, given that this project was similar in weight to what you're suggesting with the Sian. With 2x BuWizz, it had a very respectable top speed, but acceleration had to be done carefully. With full-on acceleration, the 4 PF L motors would quickly ground the male CV joints (that connect into the wheel hubs) into a pulp -- the same fate for the 12-tooth bevel gears inside the differential. That's why, for the Koncept Mantis, I chose to use the stronger CV joints from set 42099 instead. But it might also help to use the new differential from set 42109, which I didn't have yet at the time.

Another possibility is to use direct drive: using 4 motors, each independently driving 1 wheel. This is a popular setup for buggy type models -- several can be found on Rebrickable I think.

Edited by astyanax
fixed link

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Buggy motors and Buwizz is the way to go, Kbalage is right along with many others. The Lego buggy motors are $100+ US, not cheap! You can get after market ones from China that are supposedly equal to the Lego performance and much cheaper. There are threads about both topics here on EB, just Google it.

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2 hours ago, astyanax said:

I can vouch for this setup. I used Madoca's Icarus drivetrain in the Koncept Mantis, which is comparable in size with the Sian. (Acceleration video and size comparison can be found if you follow the link.) The Mantis is pretty light though! Definitely you'll want to get rid of the gearbox and fake engine of the Sian. It may not be so simple because the Sian is not a very modular build. In contrast, the Pimped Porsche cleanly separates the chassis and bodywork. So what I once did was build the bodywork as per the Pimped Porsche instructions, and then built my own chassis -- with the correct dimensions and connection points -- but with the Icarus drivetrain and no gearbox or engine.

800x600.jpg

The bodywork fitted neatly on top:

800x600.jpg

Now you'll want to know the performance, given that this project was similar in weight to what you're suggesting with the Sian. With 2x BuWizz, it had a very respectable top speed, but acceleration had to be done carefully. With full-on acceleration, the 4 PF L motors would quickly ground the male CV joints (that connect into the wheel hubs) into a pulp -- the same fate for the 12-tooth bevel gears inside the differential. That's why, for the Koncept Mantis, I chose to use the stronger CV joints from set 42099 instead. But it might also help to use the new differential from set 42109, which I didn't have yet at the time.

Another possibility is to use direct drive: using 4 motors, each independently driving 1 wheel. This is a popular setup for buggy type models -- several can be found on Rebrickable I think.

This is great info, thank you! Even if I don't end up going with this build on the Sian, I definitely want to do this with a brand-new car, maybe even the Icarus, it sounds like a blast. I really want more 42099 CV joints, they're fantastic. I also want the new differential; I wonder if the stock diffs in the Sian will be able to handle the power as-is. 

35 minutes ago, 1963maniac said:

Buggy motors and Buwizz is the way to go, Kbalage is right along with many others. The Lego buggy motors are $100+ US, not cheap! You can get after market ones from China that are supposedly equal to the Lego performance and much cheaper. There are threads about both topics here on EB, just Google it.

I did a bit of reading here about the comparison, it was quite insightful; sounds like they're a decent bargain. Some people noted some inconsistencies in different speeds (same Chinese motors, just one faster, one slower) and that some don't last very long. Honestly though, for that price, I'd still be willing to give it a shot, at least much more willing than dropping $100 on a nearly 10 year old motor. 

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What if I told you we are working on this exact project uisng the motors which are same form factor as RC ones, but more powerful?

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2 hours ago, Zerobricks said:

What if I told you we are working on this exact project uisng the motors which are same form factor as RC ones, but more powerful?

Sorry for my confusion. Are you saying you're working on a remote-controlled Sian, or are you developing a new motor?

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On 7/7/2020 at 4:21 AM, moebiusfactor said:

I was looking at the Chinese knockoff motors as the actual Lego ones are crazy expensive; I do have one from an old, old set, but one won't do if I end up going down that route. I might consider those more seriously now though. 

 

Here's something, the knockoff L motors and XL's right now are actually MORE expensive than the actual lego motors. I regret buying 8 of the knockoffs.:grin:

Nevermind, i just checked. They were probably on sale like last week.

Edited by JoshsTechnicWorkshop

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On 7/6/2020 at 9:58 PM, kbalage said:

This is the speed you can achieve with 2 buggy motors and 2 BuWizz units in a car that has approx. half the weight of the Sián. I don't think the 1:8 LEGO supercars can achieve a speed that they'd deserve based on the size and the look. Maybe if you remove the complete interior and squeeze in 4 buggy motors and 4 BuWizz units :D 

Are the Buggy Motors really that power hungry that you need 1 Buwizz unit per motor?!

And I thought 1 Buwizz would be enough to power 2 Buggy Motors and 1 Servo...

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4 hours ago, JoshsTechnicWorkshop said:

Here's something, the knockoff L motors and XL's right now are actually MORE expensive than the actual lego motors. I regret buying 8 of the knockoffs.:grin:

Nevermind, i just checked. They were probably on sale like last week.

Depends where you are and how much shipping you pay. Genuine L motors are usually around 11€ each. Knockoffs are less, at least before shipping and customs duty, but can get to more or less the same money.

However you can't get genuine Lego L motors with 30% more power, nor 30% more power and 300% more rpm, so if that's what you want, you have to play Marco Polo.

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1 hour ago, Gray Gear said:

Are the Buggy Motors really that power hungry that you need 1 Buwizz unit per motor?!

And I thought 1 Buwizz would be enough to power 2 Buggy Motors and 1 Servo...

Depends on the gearing/size of the vehicle and whether you want to run it in ludicrous mode, but if you want to use the full potential of the buggy motor then yes, you need one BuWizz per motor.

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1 hour ago, kbalage said:

Depends on the gearing/size of the vehicle and whether you want to run it in ludicrous mode, but if you want to use the full potential of the buggy motor then yes, you need one BuWizz per motor.

Just found this out too. This weekend I finished my first buggy MOC: 999-pieces, 2 buggy motors, and 1:1 gearing from inner/fast output to new-style differential (from set 42109). With 2x BuWizz, I can do full-on acceleration in Ludicrous mode. Both BuWizz briefly flash a red light, but they hold up, and the car FLIES off. With higher gearing or less BuWizzes, you have to go easier on the throttle.

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2 hours ago, kbalage said:

Depends on the gearing/size of the vehicle and whether you want to run it in ludicrous mode, but if you want to use the full potential of the buggy motor then yes, you need one BuWizz per motor.

Thx for the reply.

I once thought about doing a 1:8 RC build, using 4 buggy motors at the rear Wheels. But no way I am spending 800€ for BuWizz + Buggy motor cost + servo cost...

I can almost build 2 manual 1:8 cars for the price I would have to pay for just the electronics...

Edited by Gray Gear

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