Limits of Bungee Chords

Hi guys! I know that I might be in the wrong thread… but does anyone know how far the default bungee chords can be stretched? I am experimenting with a new tensioning system and that data would be useful.
Thanks!!

replace it with weights, they work much better (any spring/elastic will provide
the most tension when you need it the least and the least tension when you need
it the most)

David Lang

Alright, what weight would you recommend?

Thanks!

With a stock frame, the minimum tension is just under 4 pounds, you don’t want
the weights to overwelm that tension and pull the sprockets against the other
side of the gears.

Normally, you attach the weight to the pully/sprocket in the middle of the
slack, which gives the tension of the sled a 2:1 advantage.

so you can go up to about 7 pounds.

I have about 4 pounds on mine, I use 1 gal water jugs partially filled, so I can
adjust the weight if I find something else is better.

David Lang

This is late… but I am thinking about converting to a counterweight system… could I possible get a picture of your setup along with any chain guards/guides?

Thanks!

what is this term called? (when the motor turns in the opposite direction because of weight) It happened to me today (not using a c/w system) I think that my left motor could be messed up because it can barely pull any weight at all…

Backlash? If there is no chain on the sprocket, use your fingers to try to turn the sprocket. You will feel a small turn. With either bungee or weight tensioning you do not want that to happen. A balanced weight tensioning is the the best approach to avoid this. Bungees or springs give the max force when not needed and the least when needed. Any plastic bottle filled with water or sand on a rope will do.

When I try to turn the sprocket, I get a small turn almost as if there is some play in the sprocket. However, I think that I have always had a small amount of play within the sprocket. How do I fix this issue and/or what things should I do to further troubleshoot?

The sprocket turns. Normal. Just keep the pull on the slack chain low enough to no activate that turn. The sled weight should keep it stable at all times and all positions on the sheet,

This is likely the worst weight tensioning in the forum, but the one I can find :grin:

if you can use the search in the Forum, you can find better and over engineered versions.

Here’s a video of what’s happening. Sorry for the poor quality… at the end was me moving it… disregard that.

I also found something interesting… in this video I am pulling with very little pressure all. That said, I think that it is a hardware problem with my motor.

Is the chain jumping the teeth on the sprocket? The chain seems loose. Is the sled attached on this video?

That ‘backlash’ seems normal. What exactly are you trying to do?

The sled is not attached and it is not jumping teeth… I was holding onto the chain with little pull strength.

OK, this can be a broken gear. :pensive:
Did anything bad happen, like the chain tangling around the sprocket, or something else that could have put a lot of force on the motors?

If you are confident to open the motor, you can check. Not recommended for someone who has not done this before. Looking at the first video again and again, it seems to me that one gear is gone. Not sure and I hope for you that I am wrong,

Nope… I’ll attach a pic of my setup below, I’m genuinely not sure why this got broken as I have been running this setup for about a month-two months and my motors have not taken much abuse at all. The only thing that I could think of is that since my chains are longer than normal that could have shortened the longevity. However, even with that… I thought that these motors were durable.

If this data is to any help… I do use my Maslow quite frequently for hours on end cutting 8 foot long panels. I do 3 passes per panel and I’ve probably cut about 60 panels with intricate finger joints on one side of each panel (so basically a ton of cutting)

If what i saw in the video was that you hold the chain, the motor is turning but the sprocket not, can have 2 causes:

  • The sprocket is not tightened securely on the flat side of the motor shaft
  • A gear is broken

What do I know :sweat_smile: Yes, the video is not clear

I think that sadly the gear is broken because the sprocket and the motor shaft move together. Besides I don’t think that it should ever move freely like that. Also here is hat picture… I forgot to attach it above.