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Assistance device for chins

Posted: Sat Aug 20, 2011 4:22 pm
by KenDowns
As far as I know, the basic assistance device for chins is resistance bands. These have the drawback of helping you out of the bottom but providing nothing at the top. All advice I've seen on improving chins seems to hinge on the fact that there is no device that provides constant assistance through the full range of motion (well maybe at a gym, but not at home).

So first question: is there an affordable home device for doing this I've never heard of?

Assuming no, I was pondering how to make one, and it seems simple. Take a 10 foot 2x10 plank. Put a groove in it about 2mm deep and 2mm wide at dead center. Build a little fulcrum about 1' high, drop the board's groove into the fulcrum. This gives you a teeter-totter. Stick a length of pipe on one side (standing vertical) for loading plates and you just stand on the other side. Load a 45 lb plate and you are magically 45 lbs lighter. Probably can't get cheaper or easier than that, assuming there is someplace you can slide a 10' plank so it's out of the way. Only thing I figure might be a problem is that the board is never really flat, so your feet cannot be flat on it. If there is no cheap device out there to buy, I might just build it and see how it works.

This would also be a cool way to lighten the load on a deload day for dips.

Sooner or later of course "deload" for me will be bodyweight on these exercises, but methinks that will not be for well over a year. :grin:

Re: Assistance device for chins

Posted: Sat Aug 20, 2011 7:56 pm
by Oscar_Actuary
I'm not the builder but wont that only help get you 2 feet higher before you're on your own completely

Cool idea though. Maybe build with higher fulcrum (or offset slot from center of board) and some platform that will help offset the angle.

Re: Assistance device for chins

Posted: Sat Aug 20, 2011 8:15 pm
by Jungledoc
How about a couple of pulleys? One directly above the bar, the other a few feet away. Run a rope through the pulleys, a loop on your end to hook your foot into, and hand weight from the other end. The pull will be directly up, and it will be linear loading throughout the ROM. Sounds easier to me. You could use the same set-up for some pull-downs, if you were so inclined.

Re: Assistance device for chins

Posted: Sun Aug 21, 2011 8:45 am
by KenDowns
Jungledoc wrote:How about a couple of pulleys? One directly above the bar, the other a few feet away. Run a rope through the pulleys, a loop on your end to hook your foot into, and hand weight from the other end. The pull will be directly up, and it will be linear loading throughout the ROM. Sounds easier to me. You could use the same set-up for some pull-downs, if you were so inclined.
Yup, this is option two.

I was going for the teeter-totter because I happen to have that plank lying around, and even though it would take thirty minutes or less to groove the board and make a fulcrum, it lack the flexibility of a pulley, which can be put to any number of uses.

If I go the pulley route I'll have to add a chin bar to my cage, and the two pulleys could go onto the cage nicely. But I can't visualize how to easily add weight. Will have to think about that.

Re: Assistance device for chins

Posted: Sun Aug 21, 2011 9:29 am
by stuward
Two eye bolts in the ceiling can work as pulleys, or you can hang pulleys off them if the friction is too high. A loading pin with a snap link or carabiner will hold the plates. I'm sure you could build one out of a dowel and an eye bolt that would be strong enough for the purpose. If you need a heavy duty one, they're about $50-60.

http://ironmind-store.com/prodinfo.asp?number=1314%2DC" onclick="window.open(this.href);return false;

You can even build a loading pin from a piece of chain and a couple of bolts. http://homemadegymstuff.blogspot.com/20 ... g-pin.html" onclick="window.open(this.href);return false;

Re: Assistance device for chins

Posted: Sun Aug 21, 2011 10:32 am
by KenDowns
I think this home-made job would replace the 50.00 USD item, and then we're in business.

The two pulleys would have to be aligned with tremendous precision so the cable is pulling dead on the axis and not twisting the pulleys to left or right.

Hmmm, sounds quite doable, I think this is how I might go, attach to pulleys to ceiling and hang a chin bar from ceiling.

Re: Assistance device for chins

Posted: Sun Aug 21, 2011 11:30 am
by stuward
You could just drill a hole through the bottom of the pipe. Put a bolt through. The cable or chain could attach to the bolt and the ends of the bolt would act as the stop at the bottom for the plates.

Re: Assistance device for chins

Posted: Mon Aug 22, 2011 2:39 am
by Jungledoc
Use a floor flange at the bottom of the pipe!

Drill holes at the top, and make a cable loop, or a wire loop, or use a carabiner or something, as long as it's smaller then the 2" holes in your plates.

Re: Assistance device for chins

Posted: Mon Aug 22, 2011 8:44 am
by KenDowns
Jungledoc wrote:Use a floor flange at the bottom of the pipe!

Drill holes at the top, and make a cable loop, or a wire loop, or use a carabiner or something, as long as it's smaller then the 2" holes in your plates.
Doc, you beat me to it and I should have thought of that since I've used them on my homemade weight tree.

Assembly may begin this evening, now I have to figure out where to hang this stuff in my little gym area.

Re: Assistance device for chins

Posted: Fri Aug 26, 2011 1:54 pm
by KenDowns
Rigged up a very simple test.

As expected, using handles as stirrups, the pull upward gets a nice even boost. So this works to adjust your weight down as much as you want.

Got a surprise on the way down. There is a tendency for your legs and hips to fold up unless you actively push downward. I did not get that noticeably with resistance bands so was not expecting it. But of course it makes sense as soon as it happens to you. I mean, what else could happen?

Not sure what to do about that. Just get used to pushing down? Seems simple enough.

Before rigging anything up permanently, I'm considering how to use it with a dip station, will the back-swing of legs significantly mess it up and make it useless?

Re: Assistance device for chins

Posted: Sun Sep 11, 2011 2:27 pm
by KenDowns
Final note on this, my "teeter-totter" worked brilliantly for the kids. They are short enough to be able to stay rigid through full ROM and get the full benefit of the assistance. A big hit.