Speed test: PF V1 / PF V2 / SBrick / BuWizz

[Sariel]

Now that I have the GoPro 5 camera which can record speed on video, I wanted to use it for comparing how various power supply options affect speed of LEGO motors: old PF battery box, new PF battery box, V1 and V2 PF receivers, SBrick and BuWizz. Various AA batteries, too. However, in the imperfect conditions I was running my tests in, all results came out pretty close. I admit that this test could have been conducted in a better way.

 

Edited June 25, 2017 by Sariel

[Marxpek]

Good idea, i'm very interested, but it seems the buggy motor has no problem handling any of this, i think if you gear it up and give the motor more resistance (and a cleaner track ;D) it will show better results, since it will need more current and that is what determines the true power here i think.

[mocbuild101]

I'm glad someone has finally compared every option (I would have done it, but I don't have a SBrick or BuWizz!), it is very strange why the SBrick went so slow - maybe you are right about it being faulty...

It's also surprising why they all came so close in speed to each other, but it did seem like you did the tests on rough ground.

[kbalage]

It's a good test to set realistic expectations abut the different power sources if you have a heavier model. Swapping only the battery box won't make any miracles - reducing the weight has more visible results.

[PorkyMonster]

When different power sources produce similar top speed under the same condition, it means that condition is not tough enough... so it is time to raise the stake - toughen the condition (as @Marxpek suggested) - gear up, or go up-hill... that'll force more current to be needed, and we'll then see which power source is able to meet the demand in a sustainable way.

[DugaldIC]

Also it's not a very fair test as all battery's are moving the same wight, but one of the biggest benifits of the lipo and Buwizz are their light weight. One of the reasons I love the buwizz are the weight savings. 

[TechnicRCRacer]

The Sbrick probably has something wrong with it (firmware update?) because I have used it with buggy motor several times and t performs better than v2 for me. 

[nerdsforprez]

Well, if anything, this little study only showed me how ignorant I am of Lego PF     So... take the following questions with a grain of salt.  Totally owning my ignorance here.......

 

I know there are significant differences between V1 and V2 receivers, but do those differences only occur when using 8878?  If not, why not do the V1 and V2 tests with the PF battery boxes?  Are you assuming whatever differences exist with 8878 also apply to the PF boxes?  Both old and new?  Why test configurations if you are not going to test all of them? 

Also.... and I think this was already acknowledged, but yes.... the cobble-like surface not only is not the best surface..... but it may even invalidate your results.  And why the highest value.....you should take the average.   Especially on a bumpy surface, the variation on a bumpy surface is likely very important. 

The idea of the video is great, but the execution leaves me with many more questions than answers. 

[Sariel]

4 hours ago, DugaldIC said:

Also it's not a very fair test as all battery's are moving the same wight

With all due respect, I think that's exactly why it's fair. If the chassis' weight was changed between tests, how would the results be reliable?

2 hours ago, nerdsforprez said:

I know there are significant differences between V1 and V2 receivers, but do those differences only occur when using 8878?  If not, why not do the V1 and V2 tests with the PF battery boxes?

Especially on a bumpy surface, the variation on a bumpy surface is likely very important.

The differences between V1 and V2 occur with all power supplies and I've used 8878 because - unlike regular batteries - it maintains constant voltage almost until it runs dry. So 8878 was pretty much a guarantee that both V1 and V2 receiver would get the same voltage for the test.

Also, the surface wasn't bumpy. Come on folks, it's a regular tarmac and you're talking like it was some hardcore off-road trail.

 

[DugaldIC]

@Sariel With all due respect, I think that's exactly why it's fair. If the chassis' weight was changed between tests, how would the results be reliable?

If the chassis was the same and only difference being the battery/reciever without everything being in at the same time you would then see what benifits a lighter power source would make? Maybe that's just me. I like the concept and it's cool to see how they all work under the same conditions. It's just not demonstrating the power to weight benifits of the lighter batteries. 

Edited June 25, 2017 by DugaldIC

[Sariel]

I don't see how to demonstrate it without making the test unfair, sorry. Perhaps I should have just mentioned the weight of each power supply.

[PorkyMonster]

I see two different aspects here - (1) how weight differences of different power sources affect the overall weight and therefore speed, and (2) how different power sources serve out power when the model calls for it (e.g. under stress conditions).

I don't think (1) is as useful as (2), since if we know the result of (2), we don't really need to know (1), but not the other way round.

Edited June 26, 2017 by PorkyMonster