nerdsforprez

Hello All - As Technic MOCs get bigger and badder, with improved controllers and battery sources powering them, I have noticed that hard-coupling motors together in most supercars and large construction-themed Technic MOCs is becoming more and more common. Now, Philo has shown that there really is no difference in RPM and power between hard-coupling motors or coupling them through an adder http://www.philohome.com/motors/motorcomp.htm Despite this, the assumption that Lego motors run at similar RPMs is still important to consider when hard-coupling them because if one is slower than the other it can degrade performance over time, and perhaps even permanently damage a motor (another good source of information is Sariel’s book, 1st version, The Unofficial Lego Technic Builder’s Guide, Chapter 18). During a recent build of mine I was challenged to really think about how consistent motors are when I accidentally noticed how inaccurate the RPMs were when running two M motors off a single PF battery pack. I noticed that even with the naked eye I could detect difference in their RPMs. This led me to ask "How much difference is there really?" and to wonder if more damage than previously thought is caused by coupling PF motors. This led to the little experiment below. (Note: caution when setting the volume; set it fairly low and adjust from there. It changes greatly during the film as I slowed down, then ran it at regular speed. Usually I run a song or something over the audio but not here, I felt the audio an important part of the actual content of the experiment). Little information of the experiment. 4 M motors, and 4 XL motors were compared against each other for speed. 10 seconds each trial. Trials compared each motor, one against the other. Example: 1 versus 2, 1 versus 3, 1 vs. 4, 2 vs. 3, etc. (you get the picture). RPMs for the same motor, but different trials slightly differed because although I tried to run each trial for exactly 10 seconds, when I examined the film with digital software I noticed that there were slight deviations in the trial time (10.4, 9.6 seconds, etc.). These deviations are so small, but when you are running motors at several hundred RPMs then even fraction of a second can result in several additional turns. These little deviations did not matter because trials were independent. Winners in each bracket (M motors, XL motors) beat all other motors in independent trials. As can be seen in the video, the differences were not huge. M motors and XL motors were 100% similar in their average inconsistency (5.5 percent). To summarize, I think this is little variability and likely really does not lead to much damage or decrease in overall output (same conclusion made by Sariel and Philo; referenced above). Two things to consider however, and I think are new contributions not made by others, is that although there really is only 5.5% difference (average) between motors, when they operate at like 405 RPMs (M motor, Philo for reference) then we are still talking about quite a bit of difference, at least in revolutions per minute between differing motors (~23). When you put it that way, the difference seems a little more significant. Lastly, if one is going to hard-couple two motors together, he/she may want to examine the speed of both independently first. Although average difference is not that bad, at the tail ends of the distribution large differences can exist. The largest difference in my little examination in the M and XL motors was around 9%. For M motors that is around 40 RPMs different and for XL motors that is around 20…. Which really sound bad, especially when considering over the long haul! So, check motors for reliability first before hard-coupling them, you don’t want to get combinations such as 1 vs. 2 in my experiment, where unreliability between motors is fairly high!

I am hopping on the band wagon here......the speed at which you complete builds and the quality of each is truly astounding. I have really enjoyed each build, but this one takes the cake.....

The line between modifying and MOCing will be very fine with this set. Overhauling something will require a lot more "my own creating" than modifying what TLG did with the set. For this reason, I think this thread will be really interesting if we get some of our more seasoned builders trying to improve it. Rarely do I subscribe for notifications on a thread, but I think I will subscribe to this one. Problem is.... people actually have to buy the set to improve it.....

If you can remember where that was posted I would love to see it. I have no idea why Paul would not post it here..... it takes just about as much time to note somewhere that you are not posting it somewhere than to just post it anyways. Paul likes to get right to the meat and potatoes (pictures, video, and little narrative/information) of a post, not like he is overly verbose with details.....

Great review... thanks for all the hard work. And it really is a lot of work doing all this..... I can't really add anything that has not already been said. Expensive, colors looks like a rainbow having a seizure, and poor functions. One thing I can add, which I am surprised no one has said yet, is silverish, metallic string??? YES! sign me up. For all those crane fanatics, like me, this much better resembles the cables used on real cranes. Sadly, though, even the silver string is not worth the 279$ this set costs. But, I would definitely welcome the string in future sets.....

Agreed.

Deleted b/c posted twice Word for word from my original post ........"Now, I will reiterate; in no way do I think the following justifies the price. I will say it again - The following does NOT justify the price IMO - whew.... okay, now that I said it like 50 times......"

You must have not really read my comments very thoroughly. I stated, on several occasions, that I will not be buying the set because of the price. It is also too high in my opinion. But you cannot argue with the logic. I suppose that is why you resort with name calling. Typically that is what people do when their position or feelings are contradicted with logic that they cannot speak around.....

I have the Unimog booklets somewhere, I will see if I can dredge them up and weigh them. I don't have the others.

Don't mean to double post this.... I just made this exact comment on the 2017 set discussion but then I realized that Sariel had a whole new thread for his video review of the 42070. But I think the following is worth mentioning about the price. Now, I will reiterate; in no way do I think the following justifies the price. I will say it again - The following does NOT justify the price IMO - whew.... okay, now that I said it like 50 times I will say that I think the following is an important point to consider, and may have a tiny bit to do with the elevated price..... Great review as always. I know these reviews are a ton of work but the efforts are well worth it. Again, similar to my comment above, I think weight of the box (and set) are underappreciated. But very important and they have more significant relationships with price than do piece count. The price (want to avoid any discussion here of getting "deals" on the 'bay, Amazon, etc - what I am concerned about is Lego's pricing) will bug people for a long time. Deter many, including me - and the following in no way actually justifies the price, IMO, but it is something I think to note. Sariel listed the weight of the box. 4033 grams. The other two Technic sets that sit to the right and left of 1862 (piece count of 42070) are 42030 (Volvo Loader) and 8258 (crane truck). Their respective box weights are 3590 and 3570. So, 42070 weights roughly 450 grams more than either. 42030 has tons of PF whereas 8258 had slightly less than 42070. But still, 42070 is heavier, by nearly 500 grams, than either of those sets (booklets notwithstanding, please try to no get too deterred by the booklets and box. Such are heavily correlated with each other. Larger sets, larger boxes and booklets. So although they add substantially to the weight of the overall set package, so do they, to a similar degree, to comparative sets). This additional weight has to count for something, and I assume it has something to do with the price. Of note, 42070 is heavier (box and all) than the next FIVE sets in succession (piece count), beginning with, like I said, 8258, and then 8285, 8421, our beloved Claas (by about 1200 grams), and yes, even the Unimog (by about 400 grams). Given the Claas has 4 of the massive tires, and other sets such as the Unimog four of its massive tires (same with Volvo Loader and others) I certainly don't think the difference is only because of the massive tires in the 42070. But likely part of it. Probably a function of the panels, tires, and the overall fact it is a large model. If there still are some who are overly concerned about booklet and box in reference to the above reasoning, Sariel also published the weight of the model. 2456 grams. If there are any wonderful souls out there that have an intact Unimog or other of the mentioned sets above (with batteries) that would be willing to weigh and submit it would be interesting to compare how much actual ABS the 42070 has in relation to other large sets with similar piece counts.......

Great review as always. I know these reviews are a ton of work but the efforts are well worth it. Again, similar to my comment above, I think weight of the box (and set) are underappreciated. But very important and they have more significant relationships with price than do piece count. The price (want to avoid any discussion here of getting "deals" on the 'bay, Amazon, etc - what I am concerned about is Lego's pricing) will bug people for a long time. Deter many, including me - and the following in no way actually justifies the price, IMO, but it is something I think to note. Sariel listed the weight of the box. 4033 grams. The other two Technic sets that sit to the right and left of 1862 (piece count of 42070) are 42030 (Volvo Loader) and 8258 (crane truck). Their respective box weights are 3590 and 3570. So, 42070 weights roughly 450 grams more than either. 42030 has tons of PF whereas 8258 had slightly less than 42070. But still, 42070 is heavier, by nearly 500 grams, than either of those sets (booklets notwithstanding, please try to no get too deterred by the booklets and box. Such are heavily correlated with each other. Larger sets, larger boxes and booklets. So although they add substantially to the weight of the overall set package, so do they, to a similar degree, to comparative sets). This additional weight has to count for something, and I assume it has something to do with the price. Of note, 42070 is heavier (box and all) than the next FIVE sets in succession (piece count), beginning with, like I said, 8258, and then 8285, 8421, our beloved Claas (by about 1200 grams), and yes, even the Unimog (by about 400 grams). Given the Claas has 4 of the massive tires, and other sets such as the Unimog four of its massive tires (same with Volvo Loader and others) I certainly don't think the difference is only because of the massive tires in the 42070. But likely part of it. Probably a function of the panels, tires, and the overall fact it is a large model. If there still are some who are overly concerned about booklet and box in reference to the above reasoning, Sariel also published the weight of the model. 2456 grams. If there are any wonderful souls out there that have an intact Unimog or other of the mentioned sets above (with batteries) that would be willing to weigh and submit it would be interesting to compare how much actual ABS the 42070 has in relation to other large sets with similar piece counts.......

One thing to publish in your review is perhaps the weight of the box. I have found, in my own little unofficial data-gathering, there is a stronger relationship between price and weight of box then price and piece count. Yes I know, box weight will contain instructions, etc..... but, (as I shared about a year ago on the Porsche Pricing Thread) I have an excel file with over 100 Technic sets that once you run the numbers the relationship differences are quite noticeable. We focus so much on piece count when really we should be focusing on actual ABS (booklet and box notwithstanding) when we consider prices of sets. I don't think this no where near justifies the price, but the tires and gear, panels, etc.... they all count quite a bit towards ABS used.

With all the chatter of 42069 vs. 42070 and who is the "flagsip" set this year, I guess, if AFOLS want to unofficially mark 42069 as the flagship then the silver lining is that this year's flagship model is not the most expensive set this year. A feat that is not always accomplished !

Yes, my guess as well. Likely not longer. And less friction. This was an issue discussed a long time ago on the Porsche forum.......but when the contact of a gear on the perpendicular beam is smaller, like a smaller radius, then you have less torque, or friction. Think of like a long versus short wrench, long will have more torque. And therefore, in this application, gears that have more surface area on perpendicular beams will cause more friction, especially if that surface is far from center point. Miniscule amount to be sure......but it does add up.

Wouldn't that be cool if sales were public record? See sales of 42069 vs. 42070 in like a year. I would like to know how close AFOLS perception matches actual sales

Sample seems large enough.....I think we have a fixed application!! (worked for me as well)

Funny how 42070 gets the big box yet has many fewer pieces than 42069 (tires notwithstanding). TLG really is trying to pass this off has the "flagship" set this year. Sariel usually tells a little about box space relative to contents.......excited to see possible disparities between these two sets....

@J_C - very good point. I will take my little lego set and travel the near 1500 miles it takes to get to mountains with snow from where I live. . World geography 101.....not everywhere has mountains.......lol... But seriously, time to put a fork in my comments about the snow I guess. For the record, I don't "need" snow. It was just an observation, that's all. Back to the set....I may still get out for the parts and all. I do think it is the strongeset set for 2017. And I can't fathom going a whole year with not getting a single technic set!

Good point. But c'mon..... not sure that at least for AFOLs keeping in line with instructions is really our MO Very first modification from AFOLs, guaranteed, will be RC'ing 42069 for some outdoor driving. Contrary to Lego's position, Technic sets are easily transformed into something that can function pretty well outside. That would be my interest in the set..... but won't be able to b/c of no snow.

I am wondering if there is a whole demographic excluded with sets such as 42069. I mean, it is not like TLG has not released a snow/arctic themed set before (Arctic Explorer) but for those of us that live nowhere near snow so can sets such as 42069 loose some interest among some fans? I am well beyond my years of getting on my snow pants, grabbing my toy and going out and paying with it in the snow, but for younger fans not offered this possibility (b/c of no snow) is this irksome? Also, though I may not get down on the ground to "play" with any on model, one of my favorite things to do is RC-power Lego Technic models that don't originally have that as an option..... but if I do that for this set I will not have anywhere to drive it. Kind of a bummer for people like me (especially b/c 42069 is the only set I find worthy of its price tag) who can't take it outside to drive in the snow.......

On another note.... just prior to your response and that by @jotta93, I noticed that the thread was labeled as a "hot topic" - cool option, I did not know it existed. But then, after your and @jotta93's response, it went away. I am sure that the label responds to some simple algorithm, say X amount of responses in X amount of time? Is this correct? If so..... interesting, I had not heard of this before. I like the option.

Welcome to EB! While i like the project, and happy that you had so much fun doing it, I am going to just give a little voice of warning. You might really get some negative comments because of the spray painting. It does look a little goopy - not to mention it now makes Lego a little moot because now you really can't build anything new with it. While I am of the opinion of "live and let live" when it comes to one and their hobbies - just wanted to bring this to your attention and not get too disheartened by it. There are all sorts of opinions.... and as long has you learned something and had fun then thumbs up! Good luck in school !

Sorry guys......not working, which sucks because we all know how much work ya'all put into this site. Thanks for all the hard work you put it.... and for taking a look at this....

Setting speed records seems to be all the rage right now. LPE record? (reference to your citation). Not really sure this is a "thing." I see that your competitor has labeled his videos as "record" etc.. therefore if your build is faster you rightly could say "fastest" - but using language of "records" and "fastest" implies at least competition or some comparison sample. Yours is the fastest compared to whom? A single reference who may not be comparing his stuff against? I also created a LPE fast car.... but didn't try to label with "record" or "fastest" because not certain this is really an ongoing trend. I could very well be wrong.... and if so I certainly stand corrected..... but why try and label something as fastest if there aren't at least a good sample of others trying to do the same?

The importance of this point can't be under-rated. I respect all these recent projects trying to go faster, set records, etc., but with so much focus on the design of the machine I am wondering if there is tons of stuff being missed by not considering factors NOT machine-related. The surface in which one races being one of these..... and makes a huge difference. the most recent pictures show a surface that is so very bumpy. Remember, real-life land speed races of the fastest cars on earth took the time and effort to have the records set on surfaces that are supposed to be the flattest on earth. Like salt flats or something......