The Biggest Misunderstanding in RC Crawling - The Definitive Guide to Anti-Squat & Link Risers

Поделиться
HTML-код
  • Опубликовано: 21 ноя 2024

Комментарии • 72

  • @LittleGrey
    @LittleGrey Месяц назад +5

    I cannot tell you how happy I am someone is finally making videos like this! I’ve been involved in the crawling community for decades at this point and there have always been things that people claim will improve your crawling, but have no scientific evidence to back it up. Thank you for using your knowledge and background to help explain what does/does not work!

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      I appreciate the kind words. I hope I can keep adding to the collective knowledge.

  • @yodecaf
    @yodecaf 17 дней назад +1

    What a video! I love the subtle nods to how universal this is in all vehicles

  • @BoomslangSuss
    @BoomslangSuss  Месяц назад +7

    You can shoot the messenger if you like, but I didn't invent Anti-Squat. It's a completely proven, established and standard principle that is widely accepted by suspension engineers worldwide. I'm just sharing it because I know the RC Crawler crowd will benefit from it.

    • @jda79
      @jda79 Месяц назад +2

      @BoomslangSuss bro, the axles aplies torque to the links at the end of a lever. The ic is the fulcrum. Depending on where the ic is above on or below the 100% line, applying torque will either push the body up away from the suspension, be neutral or pull the body towards the suspension. That is it period. Acceleration and weight transfer have nothing to do with it

    • @tomsteadman9520
      @tomsteadman9520 6 дней назад +1

      ​@@jda79 your comment needs to be seen by everyone. It really is as simple as this for crawlers.

  • @vdel9036
    @vdel9036 Месяц назад +1

    I'm building the first 1/10 crawler i've designed the chassis. I've discovered your channel too late since the parts are close to be all machined.
    Happy to hear anti-squat does not affect the low speed runs i'm used to.😇

  • @rc_guy_miami
    @rc_guy_miami Месяц назад +1

    Great information! Love your channel!

  • @pocketfuloducks1062
    @pocketfuloducks1062 Месяц назад +1

    I appreciate and understand your well thought out explanation here. Thank you for presenting this.🍻

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      Thank you for watching and the kind words.

  • @TheShopMiniRC
    @TheShopMiniRC Месяц назад +3

    If anti squat doesnt hurt slow crawling then there is no reason to not have some antisquat for when you bump it up a rock or line quickly. Its pretty rare that there isnt a time in a run where you need to quickly bump yourself up and over a ledge, anti squat would then help with that quick movement right?

    • @rcrockcrawler
      @rcrockcrawler Месяц назад +1

      That's how I see it. Even more so when the rocks are covered with sand or dust or making jumps from one rock to the next.

    • @Glocktologist
      @Glocktologist Месяц назад +2

      Anti-squat will make the rear end stiffer on power, so it won’t be as compliant over bumps.
      A car with a lot of anti-squat can get jumpy when accelerating over bumps. Less anti-squat allows the tires to move up and compress the suspension with the rest of the car floating forward, dragging its belly.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +2

      @rcrockcrawler Your vehicle definitely has some amount anti-squat automatically. You should know how much before adding more. Don't just add more without knowing.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      @Glocktologist Agreed. You want the "right" amount of AS, not just "more".

    • @rcrockcrawler
      @rcrockcrawler Месяц назад +1

      @@BoomslangSuss How have I indicated that I “just add more without knowing”?

  • @Crawlingrc3903
    @Crawlingrc3903 Месяц назад +1

    Yeah when i first heard of doing link riser i was confused but then i seen your first vid on this and i was like yeah thats what i thought. Great video very informative

  • @extec101
    @extec101 Месяц назад +2

    @8.50 i would say if the shocks extend its anti squat and of its compressed from the forces of acceleration and chassi reaction its the oposit of anti squat its pro squating

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +1

      That’s a fair point. I guess it depends who you are talking to. For example, the definition of “full droop” can be completely opposite if you’re talking to a full scale builder versus an RC crawler. Your explanation makes the most sense.

  • @TrailTime.
    @TrailTime. Месяц назад +1

    So you’re saying link angle that produces a high antisquat value (I.e. 150%) isn’t useful compared to a bar angle that produces say 75%. I’d like to hear your opinion on high a antisquat value while considering what rear torque is doing to the unloading of the rear shocks on a climb.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      That is what I’m saying, but in the right context. Anti-squat does not matter without acceleration such as a slow uphill climb. It’s a dynamic response.
      Also bear in mind that I did not invent this. Anti-squat is well understood and accepted by suspension engineers worldwide. It’s only within the RC crawler community that some people have erroneously extrapolated that to include slow speeds, without acceleration, and believe that it pushes the front and down. But the physics don’t support that.
      Torque is a static measurement - force x lever arm - and is not a variable in any anti-squat calculations. A rapid change in torque creates acceleration, which then enters into the anti squat realm.
      Torque alone doesn’t compress or extend your rear shocks. It unweights the front end which shifts weight bias onto the rear wheel which would compress the rear shocks indirectly.

  • @westdesertwheeler
    @westdesertwheeler Месяц назад +1

    Very interesting thanks for the video credit 👍

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      You bet! Great to have met you in person.

  • @patrickgeorge4306
    @patrickgeorge4306 Месяц назад +1

    Awesome video! Couple of questions.
    In my own testing using my trx4m based rock bouncer build, it seems that raising the rear links helps a little when bouncing up and over obstacles that I can't slow crawl, like where it would high center. Seems to pop up and over better and be a little more predictable. Does that make sense or am I imagining things? I haven't run the geometry calculations on my rig, and the observations are from running it on then rocks, not from anything resembling a controlled environment.
    Second, it seems like with the links ALL the way up (just to see), the sidehill performance is worse especially when turning uphill. The rear uphill tire seems more likely to peel itself off the rocks and I loop out. Could that be attributed to the link position, or maybe just run-to-run variance? I can never hit the same line in exactly the same way lol
    last, are parts like suspension links and driveshafts considered sprung or unsprung weight? A little of both?
    LOVE the videos BTW. I'm a full time auto tech, and being able to observe all this theory on a small scale is 100% what got me into crawling. Having your explanations on the theory is an awesome resource.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +1

      It’s hard to deduce anything from an uncontrolled environment 😂 but you are on the right track. An increase in anti-squat will stiffen the rear suspension when you punch the throttle and that seems to be what you’re describing.
      For side hilling it really should have no effect.
      If you’re trying to calculate your sprung and unsprung weight, very precisely, normally put 50% of your link and driveshaft weight to each.
      You could also take apart your shocks and weigh the body and the piston separately, or just assume half of the shock weight on unsprung and half on sprung.
      1/10th scale 10 mm shocks have very little difference in weight whether you mount them up or down and I did a video on that.

    • @patrickgeorge4306
      @patrickgeorge4306 Месяц назад +1

      @BoomslangSuss Thanks for the reply! As far as the sidehill behavior where the uphill rear tire unloads, do you have any general tips or suggestions to improve that?
      The rig in question is a trx4m injora tarantula, about 25% OD, 61/39 weight distribution, 59mm shocks with custom mounts on the body. At full compression the lower links are pretty much parallel to the ground. Front shocks are rubbed banded for full droop, rear have no bands and sit about 75% compressed at rest. Wondering if I have too much travel, or maybe should try banding the rear. It's like if it gets past a certain point of leaning, the body roll kinda gets too much leverage on the rear axle. Hope that description makes sense haha.
      Totally appreciate you dropping the knowledge!

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      Despite what a lot of people think, you can’t improve sidehilling with linkage. Lower CG is really the only thing.

  • @theoalbert897
    @theoalbert897 Месяц назад +1

    There is alot that I know first hand is untrue in this video.. first and most importantly torque is what decides anti squat after link separation, link separation is more important at the chassis that at the axle and when both are used you can easily achiever the rear shocks lifting instead of compressing under torque.. this makes a huge difference with bumping up a ledge even with low wheel speeds and the suspension is harder to compress under acceleration..

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      The physics in the video are correct. Torque is not a variable in anti squat calculation.

  • @Casitascrawlers
    @Casitascrawlers Месяц назад +2

    How do after market link risers affect performance they have extra holes in them so you can move your links to different positions you have upper link extenders & mounts & axle mounted link mounts also with multiple holes to move the links.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +2

      Generally, if you move your links to a higher hole on a link riser the AS value increases. But that’s not necessarily always the case so you’d want to verify. It’s up to you to determine how much AS you like. 70-90 is a good range. But remember, it only benefits during acceleration, not slow climbing.

  • @hotboyracing
    @hotboyracing Месяц назад +1

    I recently did a 4ws swap on my h10 optic using a optic front axle and that moved the links in the rear up and apart greatly I haven’t got to run it yet but I feel like it’ll create issues

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      Apart is generally bad for stiffness and triangulation.

    • @hotboyracing
      @hotboyracing Месяц назад +1

      @@BoomslangSuss I went about the same width apart on the front where it mounted to the chassis when I re installed them to keep the trianglation about the same as it was

  • @stefan-norge
    @stefan-norge Месяц назад +1

    Usefull again, thanks 👍🏻

  • @corneltc
    @corneltc Месяц назад +1

    But isn't just standing still on an incline, actually accelerating parallel to the hill, to fight the slope projection of gravity. I mean, the cars have different postures when standing on a horizontal distance vs incline. As an intuition, when driving uphill in a normal gasoline car, you find that the engine is accelerating even though the car's speed is constant. An electric motor when standing on an incline, is drag braking, which is basically acceleration to stand still on an incline. And anyway you have acceleration from moments when you stop on a hill and start going again, less again bumps. My point for sure, constant speed on an incline is actually acceleration to stop gravity, and anti-squat is at work here.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +1

      If you can’t SEE an acceleration - faster and faster and faster - it’s not there. Plus the only acceleration relevant to AS is the wheels accelerating out from under the chassis.

  • @Gibsonlife573
    @Gibsonlife573 Месяц назад +1

    If I not be Auntie squad or whatever but I know this when I change my upper links it definitely performs different if I raise them up in the rear versus dropping them down I have definitely seen different performance 100% I don't know what it does or what it does it but I just know it helps LOL

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      Auntie Squad - sounds like a great name for a band. 😉

  • @shuster1921
    @shuster1921 Месяц назад +1

    Will there be a quiz on this? Sadly, my dog ate my homework,,, again😂🤣

  • @forrestcrabbe
    @forrestcrabbe Месяц назад +1

    🤘🍻🤘

  • @jda79
    @jda79 Месяц назад +2

    Anytime you apply torque it matters. If the slow crawler had really bad geometry appling torque can load or unload the vehicles it was you dont want😂

    • @extec101
      @extec101 Месяц назад

      Yes any time you apply torque high enough to pull the links and cause a chassi reaction.

    • @jda79
      @jda79 Месяц назад

      @extec101 any amount is enough, even if you can't see it

  • @whitsrcleftovers2707
    @whitsrcleftovers2707 Месяц назад +2

    Even knowing better haha, my biggest mistake with tuning, is changing more than one thing at a time. Instead of just changing shock angle, I'll change angle AND spring, or angle AND something else lol, just can't leave it alone.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +1

      "One Thing at a Time" - that deserves it's own video! Keep on playin'

    • @Glocktologist
      @Glocktologist Месяц назад +2

      ”One thing at a time” is a great principle but don’t follow it blindly. Some setup changes may only work correctly if you make another change to compensate for a side-effect you want to eliminate, for example.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      @Glocktologist I'm trying to think of an example of that???

    • @Glocktologist
      @Glocktologist Месяц назад +1

      @BoomslangSuss these may be interpreted as a single change, but you may sometimes change the shock pistons and the oil at the same time to adjust high-speed damping one way or the other while maintaining a similar low-speed damping as before.
      When going from one track to another one with more grip, you may want thicker sway bars and you change them both in the front and rear: changing just one would affect the grip balance of the car. Changing the balance could be what you want so it’s not a given that changing one sway bar means touching the other.
      Or, you may want to combine changing the axle height on a buggy with raising or lowering the camber link at either end to maintain the same link angle as before.
      Rear toe-in and anti-squat may also benefit from simultaneous adjustments.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      Good observations. Thanks for sharing.

  • @nicholasstephey8475
    @nicholasstephey8475 Месяц назад +1

    Has nothing to do with velocity or acceleration.
    Anti squat takes place as soon as power is applied..
    people please do your own testing hit a line, change your link position and hit the line again. Learn for your self’s. 🤦‍♂️🤦‍♂️🤦‍♂️🤦‍♂️

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +2

      @nicholasstephey8475 And there it is, right on cue. Heartbroken, confirmation bias, placebo and testing protocol. I teed it up and YOU knocked it out of the park. Ticked all the boxes and you clearly didn't even watch the video! Thanks buddy! You proved my point perfectly.

    • @nicholasstephey8475
      @nicholasstephey8475 Месяц назад +1

      @@BoomslangSuss lol. 🤡. I watched your video, and that is what prompted my comment..
      Sorry to question your brilliance, oh great one. You said it on the internet therefore all sheep shall follow.
      I advice people to be free thinkers and test for them self’s.. NOPE listen to the great one’s theory’s.
      As brilliant as you are, you must have 100’s of podium finish’s under your belt.
      When I have a second of time to waste, I will make a video to show how anti squat affects a truck without acceleration.
      Maybe in all your great wisdom, you could have took a step back and asked why I commented that way..🤡

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +2

      Shoot the messenger if you like but it’s not my theory. It’s been widely accepted and proven by suspension engineers worldwide for decades. Many RC crawler builders are slow to adopt it which is why made the video. If you can produce a video that meets scientific rigor I’d love to see it. Show me a double blind test.
      I understand your pov precisely because I’ve heard it a thousand times. In the case of anti squat, you’re not going to change physics with more field testing. People should give up on link risers that don’t do anything and focus on the areas I suggest that actually do make a difference. We’ll all make progress much faster.

    • @nicholasstephey8475
      @nicholasstephey8475 Месяц назад +1

      @@BoomslangSuss 🤣🤣

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +1

      I’m just goofing with you my friend. Would love to see a video but I know it will be hard to demonstrate.

  • @jerryvolpini7987
    @jerryvolpini7987 Месяц назад +1

    I don't have the science and math background but I do like to do a lot of testing. It just never made sense to me that so much of the theory we use for our little crawlers comes from the 1:1 crawler world and rock racers where momentum/velocity/acceleration are vastly different. Still, I 'assumed' link risers worked. Then, after a year, I decided to remove them for testing and never put them back on. Why? Because my testing showed they did absolutely nothing to help performance (well, not saying no anti-squat but not as much as a link riser adds). I don't really understand all the math (although you do a great job of explaining it) but I know what works. And I loved your comment about confirmation bias and double blind tests - too many people just accept things as fact (I initially did). I get it, people want the magic bullet and often don't put in the testing but this is why we need to. Overall, fantastic video! 👍

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +1

      I love it Jerry. Test, test, test... as long as it's still fun.
      You've heard me say it - RC Crawling has very little in common with full scale vehicles.
      Reality SHOULD correspond with your testing. If not, either the theory or the testing is flawed. Too often it's the testing when it comes to simple toys lol.

    • @lastcreations8845
      @lastcreations8845 Месяц назад +1

      originally stemmed from drag racing, stock car, etc... then was developed very early in 1:1 rock crawling (absolutely nothing to do with rock racing). The relation from 1:1 to rc does correspond greatly, but not fully in some specifics.

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      #facts

    • @jerryvolpini7987
      @jerryvolpini7987 Месяц назад

      @@lastcreations8845 Huh?! Videos, articles, almost all reference materials about RC crawling refer to 1:1 rock crawling and, when talking about link risers and anti-squat, rock racing is almost always used as an example. Likewise, almost everyone I talk to refers to 1:1 crawling as their basis for tuning and a large part of that comes from the rock racing community. Yes, it might apply to drag racing and stock cars but I've NEVER heard anyone refer to them as an example for our RC crawlers. I mean, those forms of racing are so different from what we do that they have no relevance (except for some basic theory, maybe)?

  • @Grandmoi-sc2wn
    @Grandmoi-sc2wn Месяц назад +1

    Merci pour toutes ces explications. Etant français j'ai pas tout compris puisque je ne parle pas anglais, a moi de chercher les traduction 🤣
    👍🛻👽

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад +1

      Je vais essayer d'ajouter des sous-titres Français, si possible

    • @Grandmoi-sc2wn
      @Grandmoi-sc2wn Месяц назад +1

      @@BoomslangSuss J'ai vu qu'il y avait la version Booktexte publié il y a 6 mois. En tout cas merci pour toutes tes explications 👍

    • @BoomslangSuss
      @BoomslangSuss  Месяц назад

      De rien!