Elevator Crash Testing the Otis-Inspired Safety Brake! Garage Attic Lift Build in Minneapolis
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- čas přidán 27. 04. 2021
- We finally test the safety brake! Will it fail? Will it succeed? Find out above!
Elevator Build: • Garage Attic Elevator ...
Brake Build: • Garage Elevator Emerge... - Jak na to + styl
Wanted to build a garage lift years ago...... My "analysis paralysis" and procrastination FINALLY paid off! I found your videos and THIS is WHAT I was LOOKING FOR! Coming from an engineer 🤓, you guys did a TERRIFIC job from a DIY perspective. Looking forward to building my own (Inspired from your design & engineering) now. New Subscriber and looking forward to going through all of your content now.
My elevator is remarkably similar to yours. I too used two 330lb. fall arresters as a safety . I have a wireless remote system to move the elevator up and down and high and low limit switches stop it in the up and down position. I also added emergency stop switches in case a limit switch fails. The emergency stop switches kill power to the lift if a limit switch is over run or fails.
I am very impressed with the Otis safety. Very well thought out and implemented. I also appreciate you sharing your testing. Ive tested my lift to 600 pounds and rate it as 400 for practical working load. I weigh 300 pounds and the platform and associated hardware is just under 90 pounds. My first lift motor is rated a 880lbs. I use a second lift motor as a "swap-out" unit and it's rated at 1320lbs. I swap the lift motor every 3 months so I can maintenance the active lift motor. I check and grease the bushings/bearings, check the cable for defects and disassemble the motor to check gear wear and apply fresh grease. I'm still adjusting my maintenance schedule as I learn what wears. I know this is not popular but we actually use our lift to get my mother-in-law up to her second floor apartment. I can not recommend any one else ride their lift... But I assure you it's safer than my 87 year old mother-in-law walking up the steps... She fell down them more than once. Do with that what you will.
Good job guys!! I'll be modifying mine with your brake.
Just Awesome! Very well designed and thank you so much for sharing. Unlike many You-tubers, you actually followed up from previous videos and showed your progress. Thank you for that and again... VERY well done.
Well done guys! Reminds me of my underground mining days. I had do a drop test on an man cage before it would could be certified for man hoisting underground. The cage had wooden guides. I had to design the safety dogs to engage the guides if the hoist cable broke. They had to engage and decelerate the man cage at a rate such that the occupants were mot injured… such as broken legs, hips or backs!! The weight of the cage on the cable kept the safety dog disengaged. Cool stuff!!
Outstanding. I will need to go back and look at the details of how the brake was designed so I can implement a similar solution. Thanks for all the effort and sharing.
Cool man, thank you. I have t say, I'm very pleased. Share it on your social media if you can. We are not big time. We appreciate it.
One other safety mechanism you might consider is a top limit switch. If the elevator is stopped at the top position the winch could damage the carriage, or break the cable. A top limit switch would kill power to the winch before that happens.
Thanks for this series. There's a very good chance I'll be (helping) building a similar system for an in the house elevator at my grandparents soon and I'll definitely be sharing this series with my uncles and grandpa while we're designing. It has been a huge help for me to supplement along with their (grandpa's) book from 1919. If an old system works, use it. 👍🏼😁
Thats the one i looking for
That's pretty sweet, don't know if it would impact the braking system but it might be worth putting another 2x4 or something similar between the one holding the rails and the brakes so if it does ever have to get used there's no chance that it mangles the 2x4 holding the rail and you have to disassemble everything to replace it.
Love the videos! Curious if you have tested the fall arresters like you tested the emergency brake? That would be a great video too. I am currently building my lift.
Thanks for the vid.......There's little doubt it's helping a lot of people ........
I am almost finished with my garage lift and wanted to thank you for your excellent videos, especially your fall safety. I have found a ready made fall safety that was designed for a different application that works extremely well and can be adapted fairly easily. I was thinking about making a video but wanted to know if it would be worth the effort and the liability issues from posting safety related issues.
Impressive. Thank you
Very nice. Good job. I've got a 1930's freight elevator that needs a brake. Gives me some ideas. Thanks for sharing.
Just subscribed, love the ingenuity guys
Thank you man!
I own an elevator company in NYC and I have an Original Safety Otis Brothers from 1865 with the rails.. The Original rails were notched cast iron ....not wood
This is so cool!
Now try it with you on it.
What you have works fine IF the cable breaks. What if the braking mechanism in the hoist breaks or the gears strip out and it starts falling- but falls with enough tension on the cable that the safety mechanism doesn't engage? Since your hoist is a cheap Chinese unit this is a distinct possibility. Same with the fall arrestors. If it's a slower fall they probably will not engage either. Lets see you take the hoist apart, see how the brake works and simulate a failure there with both the braking mechanism then the fall arrestors. Thanks for the video.
nice video. would like to see the fall arrester crash test too
Very cool dude. Love it.
Thank you buddy. Share it social media for us please. We appreciate it. Tell everyone we said "hey". We all gotta get together the next time I'm out there.
@@theelevator3615 can you leave your eamil? we are a tool manufacturer want to cooperate with you
At the 3:00 mark the levers are in a different position than the second test?
Additionally, did the original fall arrestors not server their intended purpose ?
Parabéns amigo 👏👏👏
Great job any possibilities of how the breakes are made or some drawings so we can diy ourselves thanks
What’s the safety system when the winch fails and keeps enough tension on the line to keep the spring brake from engaging?
What are the dimensions of the elevator & opening in ceiling? I'm building a garage and it will have 13' ceilings. Any issues you can forsee with it going that high up?
Wow so cool!!!!!
Thanks Julio!
Thank you Julia!
Parabéns vi todos seus videos muito bom agora faz um passo a passo que ajuda bastante tenho que fazer um para cadeirante preciso fazer um sistema para a segurança deles, obrigado boa noite fique com Deus.
can you give me the details on how to make a safety break in the home made elevator thank you
The second time you tried, you had forgotten to remove the fall arrests?
אך אפשר להזמין ולקנות את המוצר וכמה זה עולה הכל ביחד
Woohoo!
Very pleased buddy!
lol your wife must either really love you or wants you to stay busy doing something! Awesome stuff, question is, how do I replicate this and how do I talk the boss into letting me build something like this.?
איך ניתן להזמין ולקנות את המוצר הזה
Otis!
Very cool! :) I knew that braking system would work, but I was definitely surprised at how quickly it stopped the platform from falling! I figured it would drop a foot or two before everything would move into place.
👍💪✌
Watched this video quite a while ago. Looking at again I think you could achieve the same net effect with far less components.
Show us!
@Tony Turner can't post pictures here, but I can explain the science behind it... He has two fixed (with bolts) vertical bars hanging down from the horizontal piece of wood, for simplicity sake I will call these "drop bars". You can see in the video he has a vertical spreader bar placed down low that goes between them. That is there because of Newton's Third Law of Motion, but that can be removed if it is slightly redesigned.
The reason the bar is there is because the two fulcrum arms are independent of each other, and each of them is designed to press into the wood without a counter acting force. i.e. they are trying to press into the wood, but there is nothing to stop the wood pushing back. So he has a bar between them to provide that counter resistive force. Effectively nullifying the pressure pushing back.
BUT... If you added a small pivoted joiner bar (or just made a pivot point between the two fulcrum arms) at the ends of the two independent fulcrum arms, you would in essence have one flexible fulcrum arm acting in two spots, which would double as a spreader bar. By joining the ends of the fulcrum arms you could also do away with some if not all of the limiters. Because you would make the fulcrum arm just the right length so that it can never go over centre. With the design he has there he needs a limiter because there is a possibility that a single independent arm can potentially go past centre with enough force.
By making the total bar slightly longer than the distance between the fully engaged position, it isn't possible to go over centre (well not if it is designed right it shouldn't) plus you have the added benefit of knowing that equal force is being applied to both sides. Alternately if you wanted the bar to be able to go straight, I can think of a way that the arms can lock on each other (much like folding your arms).
That brings us to the "drop arms"... Modifying it the way I suggested creates one small problem with a better solution answer. Using independent arms you don't need to worry about the arc trajectory they travel in, but joining them together is going to have an impact on the pivot points on the lower drop arms because they are going to want to move is a slightly different trajectory path. But with this problem also comes an answer. Currently he has the drop bars mechanically restrained with bolts, which in turn creates its own problem, you have a steel bar bolted at right angles to a piece of wood and side leverage being applied to the bottom of it (think lever) so when the brake is applied the lever effect applied at the lower pivot point is trying to twist / sheer the bolts in the wood.
BUT... If you replace those bolts with a pivot at the top as well, you kill two birds with one stone. You not only remove the issue of the twist force being transmitted to wood, but you now have a solution to the arc problem caused by joining the fulcrum arms together.
@@DodgyBrothersEngineering that sounds workable but you can't get much simpler than what these guys have done. Their system has been used, and proven, for more than 100 years. Using soft, sacrificial wood as the friction surface is elegant and the balance of the parts are cheap and readily available. I'd love to see a drawing of your device... It could be fun to try and incorporate it into my outside elevator (which is getting built when the weather warms up). I appreciate you taking the time to type your explanation and look forward to more information if you pursue it.
@@tonyturner9146 what I was proposing may only work with their specific application and not in every case. For example I am thinking about using brake pads (of sorts) on metal to arrest the fall, whereas they are using sacrificial wood. The design I described may not work with my planned system, but might with theirs because they are using wood that is going to dig in.
What I proposed relies on the spreader bar being able to "lock" (at least partially), which means the flexible bar I described earlier must be nearly horizontal to work. If the angle is too great the force pushing back from the wood could over power the momentum / spring force pulling it down. There is a certain amount of trial and error required to what I proposed (As I am sure there was in this design), but I believe it could work with several less parts.
I most definitely wouldn't attempt to do what I proposed without a secondary or tertiary safety system, just in case it didn't engage as expected. I found an online calculator that suggested even a one floor free fall was enough to kill you, so this as important as your car brakes. I am constantly refining my idea to try and make it more fool proof as I could be using it to move quite heavy objects like fridges (or heavier).
To me the ultimate lift brake is one that doesn't rely on parts that can fail or get weak, or in the case of wood, rot. Where possible use the laws of physics to work for you, rather than against you, and use the weight of the lift to your advantage rather than a disadvantage. If I ever come up with something I am truly happy with I will make a video of it and put it up on my channel, but at the moment all my energy is going into finishing off my remote control mower, which is where I should be now out in the garage doing a video.
Also one of the major disadvantages of this system (or you could consider it a potential design flaw) is that it is relying on the rails it is attached to not move while being pushed sideways. Lets get a little crazy and say for some reason something compromised the integrity of the lift legs that allowed them to move under load. The brake has the potential to not come on at all. That is why I prefer something that squeezes a rail, or applies equal force to both sides. To just eliminate one more potential weak link.
@@DodgyBrothersEngineering it's fun to think about all the ways we can improve safety. It gives tinkers like me something to experiment with.
The system these guys are using has been used for a very long time and the only real difference is the wood. Lots of things "could" happen to the wood but we deal with the probability of what happens in the real world application. Let's say the stop arm jams into the wood and the wood splits... It would most likely not stop the car but would still provide deceleration which is ultimately the goal (stoping free fall). Or it could jam in one side and skew the platform causing it to jam (also not a bad thing). Interesting to think about. I really don't think either of those things will happen but I'm sure they could under some condition
In a real elevator there is a counter weight to the car/platform. The counter weight is connected with multiple cables each capable of carrying the full weight of the system. The counter weight is sized to be equal to the car and half the expected or rated load. In this situation the car is for the most part balanced which means the motor only feels the portion of the weight that is imbalanced. The extra cables provide redundancy increasing the safety.
Anyway, it's a fun exercise for the mind but we can literally add things to the car until it can't carry all the weight of the safeties.
Keep it simple. In my mind, and seeing the test these guys have done, I think their solution is elegantly simple and I'll be incorporating it in to my current lift.
What is that object fell off from top when you cut off at 300lbs?!
It’s been a while but as I recall it was one of the bungees that was pulling down from the base. It must have bounced at actuation and came off the ring. It did it’s job though. Once it pulled the jamming bars down, the weight of the elevator and the friction did the rest.
Do the brakes lock into slots in the unistrut or is it like a rubber pad that applies friction to stop it? Are you concerned at all of the unistrut giving way or possibly loosening the firring strips as the brakes push against it?
@311mdub They made a previous video showing how they built it. The brake pieces in the rear jam into the wood on the sides, and that stops the platform.
I love making snide remarks on people's deathtrap elevators but it looks like you have all your bases covered. The only thing that seems to be able to go wrong is maybe somebody or something getting crushed underneath or caught between the ceiling and the platform.
Thatta boy. I knew you could do it.
I like the safty redundancy but you should still label: NOT FOR HUMAN TRANSPORT
300
Winner winner chicken dinner on test 2!
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283
LOL. It probably was 283, one bag had a little leak! Don't tell anyone.Sshhh
My DIY wheelchair porch lift only rises 34"
So I am not adding fall protection because
death or injury from falling is unlikely.
!
Better than your original design, but introduces more problems (don't replace a metal lift cable with a crappy plastic rope!). My comments on your original video still stand - this is a dangerous design and does not follow Otis's original design which was more simple, more robust, and worked more reliably.
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