Designing automated assistant for drop sets, negatives, forced reps - need advice

Hi all,

I am new to the forums. I am an Industrial Design graduate working on a project based around body building equipment. The project is not commercial-oriented, but is something I am doing for myself for self-promotion. If all goes well I hope to have a working prototype in 2 months. I have been researching the website for a bit (started 2 surveys too) and was hoping to get some feedback on what I am doing.

The project itself is an automated device that basically substitutes a spotter for barbell exercises. Unlike support rails of a power cage, its meant to aid in lifting or alleviating the weight rather than catching it. As I see it, this may be of use for "forced reps", "negative reps" and possibly "drop sets" with a barbell. The device will include an electric motor and sensors to judge when the user needs assistance, how much and, of course, deliver it (somewhat similar to isokinetic equipment). Unfortunately, I don't have any good imagery to illustrate my ideas yet, but the way I see it, it is a thing that mounts on top or near a power cage or incline bench and holds the barbell on a cable (like a reversed lat pulldown tower).

My question is whether the idea makes sense and whether you believe it could aid you in your workout routine. This should probably be of more interest to more advanced lifters looking to diversify their routine.

I would greatly appreciate any opinions, suggestions and criticism. It would be better to hear the worst now rather than construct something useless.


The attached picture is a previous project that I did which is a folding cable machine. The current idea will be far smaller in size but I hope to get it done to the same amount of detail.


Cheers

are you the same dude posting here under different names?

[QUOTE=jackbravo;1035488813]are you the same dude posting here under different names?[/QUOTE] erm, no)

[QUOTE=gkalitv;1035465403]My question is whether the idea makes sense and whether you believe it could aid you in your workout routine. This should probably be of more interest to more advanced lifters looking to diversify their routine.
[/QUOTE]
A couple of years ago, a guy posted a thread in this forum describing a machine he was developing that did exactly what you describe. He even posted pics of a prototype. It was a horrendously complicated piece of machinery, looking like a cross between a car lift and a hydraulic press. It had cylinders and hoses running all over it and a big oil tank on the side.

Having been in a sheet metal stamping plant on several occasions, and witnessed first-hand the absolute power of such machines, I'd [i]never[/i] sit, lie, or stand in anything similar.



While I'm certainly no Luddite, there are some things that should remain as basic as possible. IMO, weight training and it's associated equipment is one of those things.














Many years ago, a company sold a kind-of-similar machine, call the Pro Spot. It was a power rack with a cable-suspended "free" bar, and operated with solenoids, relays, and sensors. It was supposed to 'catch' the bar when the trainee reached 'failure,' or otherwise was unable to get the load off of himself.

It was a commercial failure due to it's unreliability and lack of people to repair it when it (frequently) broke down. I read online somewhere a few months ago that some new company had bought the patent rights and was planning to bring this thing back to market.

I wonder if they'll assume the liability of the original company, and make good on all the lawsuits filed against it.

Easy enough for me to to visualize it as a pro spot with assist.

I probably wouldn't want it deciding for me how much assistance I needed. But if I could tell it exactly how much assistance to provide at all points of the positive and negative, yeah, that might be useful. I also don't want it stopping the bar unless I'm releasing the bar or the bar is traveling dangerously fast. I would want to use it IN a power cage with the safeties in place, because no gadget like that is going to have a track record good enough for me to trust my life to it. But within those constraints, and if it worked WELL, yeah, I'd want one. I wouldn't use it all the time, but I'd probably use it enough to make it worthwhile.

Kaiser had a line of equipment (they may still make it) that was hydraulic resistance based. You had buttons on the handles or foot pedals to press to lessen or increase the resistance. It was nice for doing drop sets as you could ease up on the resistance to keep the set going. The machines weren't any bigger than their weight stack or plate loaded counterparts. There were no sensors involved to judge when to lessen resistance, that was up to the lifter. Like Maluket said I wouldn't want the machine to judge when to provide assistance, any more than I would want a human spotter to decide (unless it was an obvious emergency of course).
What type of resistance are you planning on using?
Are you going to use some type of adjustable counter balance (kind of like a gravitron assited pullup machine) for doing drop sets? Without some type of self adjusting counter balance I don't see how you can do drop sets unless you have some type of automation to move the selector pin from the weight stack or remove plates from a barbell. Negatives would be tricky as well on pressing movements. Fighting the eccentric part of the movement is so much up to the individual, each rep is going to be a little faster than the previous as strength diminishes, it would be hard for a machine to sense when the user is actually failing.
I'd love something that could do this, but it just seems that it would be cost prohibitive for home use, and for most commercial gym use.

Thank you for the thoughtful responses. This indeed brought to new ideas and problems.

[quote=ironwill2008]Many years ago, a company sold a kind-of-similar machine, call the Pro Spot[/quote]

I did not know that. ProSpot possesses over a dozen of patents on their machines and it appears their patents are still in force. This means someone is still planning on using them like ironwill2008 said. Dunno about the lawsuit though. There is another similiar product called Weider Platinum - a home gym that uses electric resistance. The product has received many breakdown reports most of them regarding wire overheating.

[quote=ironwill2008]a guy posted a thread in this forum describing a machine he was developing that did exactly what you describe. He even posted pics of a prototype. It was a horrendously complicated piece of machinery, looking like a cross between a car lift and a hydraulic press. It had cylinders and hoses running all over it and a big oil tank on the side.[/quote]

I will try to find this thread. I am hoping to achieve something far smaller than that, since resistance will still be delivered by free weights, the device will only need to act as a car winch.

[quote=ironwill2008]there are some things that should remain as basic as possible. IMO, weight training and it's associated equipment is one of those things.[/quote]

True. Fitness industry seems overfilled with not-so-necessary products. Seems free weights and electronics don't go well together either. Although a company called Exerbotics is using electronic resistance sensitive training machines for athletes and people undergoing rehabilitation after trauma. Seems as an expensive technology though.

[quote=Maluket]I probably wouldn't want it deciding for me how much assistance I needed. But if I could tell it exactly how much assistance to provide at all points of the positive and negative, yeah, that might be useful.[/quote]

[quote=thedickus]Like Maluket said I wouldn't want the machine to judge when to provide assistance, any more than I would want a human spotter to decide (unless it was an obvious emergency of course).[/quote]

Could you pls explain why you would want that?
Or do you mean a threshold of assistance (e.g. no more than 5 kg reduction)? I am not an advanced weight lifter, but I would find it difficult to tell exactly how much help I would need after a particular rep and at which point. Even spotters and personal trainers (from my experience) usually start helping by barely touching the bar and slowly introduce more help as they see the bar not moving anywhere. I was hoping to gimmick that so in reality you would constantly be at your limit.

[quote=thedickus]What type of resistance are you planning on using?[/quote]

The resistance will still come from free weights. Instead of counter balance from drop sets I was thinking of making the machine "pull off" half of the load as the user lifts. Although this seems a bit energy inefficient.

Maluket, thedickus, you mentioned assistance on negatives during eccentric movement. I had not thought of that and meant only the lifting motion. Would assistance on eccentric be beneficial as well? I had never done these with my 1RM so I have a vague idea what its like. But I suppose there is strain and other hazards even when lowering with safety rails, like when your muscle twitches or something.

All in all, I am not so sure about the "negatives" and "drop sets" now, considering what a powerful motor that would need (particularly when someone's 1RM on bench press is around 400lb for negatives). The initial idea for this was just the forced reps which is only one variation of high intensity exercises that one should perform in moderation to begin with. On the other hand including the negatives would ramp up the manufacturing price far over 200$ which is probably beyond someone would want to pay for such an accessory.

Either way thank you for the input. It always helps with new ideas and thoughts.

Maybe you can add a low tech contraption to your machine for dropsets - something like this. When the lifter is ready for the dropset he/she lets the bar hang at the high position, attaches the "hook" to the bar, grabs the bar and proceeds with the set.

[img]http://www.shermworks.com/dropset.jpg[/img]

sherman, yeah that seems a far more feasible solution for drop sets actually.

[QUOTE=gkalitv;1035984243]The resistance will still come from free weights. Instead of counter balance from drop sets I was thinking of making the machine "pull off" half of the load as the user lifts. Although this seems a bit energy inefficient.

Maluket, thedickus, you mentioned assistance on negatives during eccentric movement. I had not thought of that and meant only the lifting motion. Would assistance on eccentric be beneficial as well? I had never done these with my 1RM so I have a vague idea what its like. But I suppose there is strain and other hazards even when lowering with safety rails, like when your muscle twitches or something.

All in all, I am not so sure about the "negatives" and "drop sets" now, considering what a powerful motor that would need (particularly when someone's 1RM on bench press is around 400lb for negatives). The initial idea for this was just the forced reps which is only one variation of high intensity exercises that one should perform in moderation to begin with. On the other hand including the negatives would ramp up the manufacturing price far over 200$ which is probably beyond someone would want to pay for such an accessory.

Either way thank you for the input. It always helps with new ideas and thoughts.[/QUOTE]
On a negative the lifter basically fights the weight of the barbell from coming down to the chest (when doing a bench press). You want to slowly lower the bar to the chest, all the while fighting gravity. Your spotter won't really help you lower the bar down, but once you've reached bottom the spotter helps you set the bar back at the top for your next negative rep. I've seen people load up the bar with more than their max weights and just do negatives. The way I've always done them is as a way to "finish" a set. Do all your reps unassisted to failure, have your spotter give you a couple of forced reps (with the same weight) then using that same weight do a couple of negatives.
I think the drop set portion would be very difficult to manufacture, especially if you're like me and prefer doing multiple drop sets. If you have to stop and connect something like a counter weight or add plates to a counter weight you might as well just strip plates off the bar.
Are you primarily trying to do this for pressing movements or for rowing movements and squats as well?

[QUOTE=thedickus;1036053333]On a negative the lifter basically fights the weight of the barbell from coming down to the chest (when doing a bench press). You want to slowly lower the bar to the chest, all the while fighting gravity. Your spotter won't really help you lower the bar down, but once you've reached bottom the spotter helps you set the bar back at the top for your next negative rep. I've seen people load up the bar with more than their max weights and just do negatives. The way I've always done them is as a way to "finish" a set. Do all your reps unassisted to failure, have your spotter give you a couple of forced reps (with the same weight) then using that same weight do a couple of negatives.
I think the drop set portion would be very difficult to manufacture, especially if you're like me and prefer doing multiple drop sets. If you have to stop and connect something like a counter weight or add plates to a counter weight you might as well just strip plates off the bar.
Are you primarily trying to do this for pressing movements or for rowing movements and squats as well?[/QUOTE]

The way you describe your unassisted/forced/negative routine seems like a common way most people do it. At least up to the forced rep part.

Using this for rowing movements also seems like a possibility, but I was planning to do it for movements that youd normally do with a barbell for the most part. This includes squats, deadlifts, military press, bench press, bicep curls, skull crushers, etc...

Earlier you mentioned you wouldnt want a human spotter to decide when you need help. Do you usually warn the person how much you plan to do by yourself for sure or do you ask for help at the moment you feel you're stuck?

[QUOTE=gkalitv;1036160403]The way you describe your unassisted/forced/negative routine seems like a common way most people do it. At least up to the forced rep part.

Using this for rowing movements also seems like a possibility, but I was planning to do it for pressing movements for the most part.

Earlier you mentioned you wouldnt want a human spotter to decide when you need help. Do you usually warn the person how much you plan to do by yourself for sure or do you ask for help at the moment you feel you're stuck?[/QUOTE]

I'll tell the spotter when I need help and exactly what I want. "Help me get three more" or something to that effect. From a spotter I want help with the lift off and then don't touch the bar until I tell you I need help. I'm not going to trust just anyone in the gym to spot me in taking a set to total (positive and negative) failure. That would have to be someone I trust. I think almost as many accidents happen in the gym due to an inexperienced spotter as happen due to the lack of a spotter.

A device for drop sets and a device for forced reps are two very different things I hope you realize this.

[QUOTE=qaz123;1036187323]A device for drop sets and a device for forced reps are two very different things I hope you realize this.[/QUOTE]

Yes, I'm well aware.
Mechanized drop sets I really don't see much of a need for. In the time it would take something mechanized to engage and safely reduce weight the bar could be racked, the lifter can hop up, strip a plate off of each side and get back on the bench. I do it all the time, takes just a few seconds. Even if I had two spotters I'm going to rack the weight anyway. I'm not going to trust that two people can strip off a weight plate at the exact same time so the bar doesn't become out of balance.

I was talking to the kid doing the assignment.

Making something that can give a true variable spot that the user can control is what he should define his goal as being.

[QUOTE=qaz123;1036191613]I was talking to the kid doing the assignment.

Making something that can give a true variable spot that the the user can control is what he should define his goal as being.[/QUOTE]

Sorry qaz123, my bad. I didn't pay attention to the user name, I thought he was asking me if I knew the difference between a drop set and forced reps.
But you're right, that should be how he states it.

[img]http://upload.wikimedia.org/wikipedia/commons/a/a2/Forklift-Truck.jpg[/img]

With vocal commands?!!?!?!!?!?!

Edit: Actually... If you took the car part off the design and mounted the front lifting mechanism on a wall, turning the tips up so the bar can't roll off and for safety during a lift it could work. Have the spotting arms be able to move closer and further apart. Have a control so the user can set a top of movement and bottom of movement height, and when the bar hits the safeties a sensor tells the machine to lift it back up to the top. Holds for a second or two there so the lifter can get back under the bar and then slowly retreat back to the bottom position while the lifter can ready himself for the next negative.

I'll accept royalties. You're welcome.

[QUOTE=trimble006;1036217203][img]http://upload.wikimedia.org/wikipedia/commons/a/a2/Forklift-Truck.jpg[/img]

With vocal commands?!!?!?!!?!?![/QUOTE]

There was actually a machine that used something like the forks on that forklift to raise the weights. It was computerized, big and green if I remember correctly.

[QUOTE=dumb.bell;1036219693]There was actually a machine that used something like the forks on that forklift to raise the weights. It was computerized, big and green if I remember correctly.[/QUOTE]

Nothing lifts like a Deere?

[QUOTE=trimble006;1036220263]Nothing lifts like a Deere?[/QUOTE]

LOL - Pretty sure it wasn't them.

I think Nebraska has or had some automated half racks, but not the ones I'm thinking of.

All this engineering so you can avoid re-racking and taking off some weights? Or a human spotter? I guess engineers have to engineer.

It makes sense in a system where resistance is already controlled by weight stacks or hydraulics. Then you can control it with a computer, voice activation, buttons, pre-programmed routines, whatever. Adding it on top of freeweights can be done too, but now you have freeweights and a weight stack like in the pro-spot. It's convoluted and unreliable, requires careful maintenance.

In commercial gyms everything related to heavy weights is designed to be as maintenance free as possible. You can do a simple hook like sherm suggested, which will require re-racking without a human spotter. But the thing takes up space you want for other things, takes longer to setup, etc.

Hard to foresee this being a popular gizmo.

[QUOTE=Detrus;1036228223]All this engineering so you can avoid re-racking and taking off some weights? Or a human spotter? I guess engineers have to engineer.

It makes sense in a system where resistance is already controlled by weight stacks or hydraulics. Then you can control it with a computer, voice activation, buttons, pre-programmed routines, whatever. Adding it on top of freeweights can be done too, but now you have freeweights and a weight stack like in the pro-spot. It's convoluted and unreliable, requires careful maintenance.

In commercial gyms everything related to heavy weights is designed to be as maintenance free as possible. You can do a simple hook like sherm suggested, which will require re-racking without a human spotter. But the thing takes up space you want for other things, takes longer to setup, etc.

Hard to foresee this being a popular gizmo.[/QUOTE]

OK, here it is - simple, maintenance free, cheap, no human spotter required (not even the you-know-what).
When you are ready to drop weight open up your grip enough for the ropes to slide free and the plates to fall. Might put some pillows out to break the fall of the plates.


[img]http://www.shermworks.com/dropsetrope.jpg[/img]

I knew I'd seen it somewhere already.

[youtube]Na4DHCLkyjY[/youtube]

Here's pretty much exactly what you are talking about OP:

[youtube]wwYO545cI5E[/youtube]