Chains super close to binding?

I think I’m almost ready to make proper cuts. But I’m concerned about the proximity of the chains to each other.

Is this normal? Did I do something wrong? I whipped up a little collar out of duct tape, but I have very little confidence in that as a long term solution. I’m concerned that the moment I take my hand off the “STOP” button, something will bind and the machine will tear itself apart.

Suggestions? Should I be looking to completely change the way the chains are setup?

Your bungee cords look to be too long, and too thin.

1 Like

I agree with @ame I think that those bungee cords were the original ones intended to be used in the old vertical configuration. I would use something a little bit more elastic or one of the counter weight designs

It would also be a good idea to have a single bungee linking both idle sprokets, that way as the sled moves to one side of the work piece the sag will auto compensate.

I believe several folks here have use that configuration.

These bungee cords were with kits that were (I think) among the first to include the metal ring. Is there a bungee cord you might recommend that I could pick up at a Home Depot / Lowe’s type hardware store?

Is there any advantage or disadvantage to moving the pinned other end of the chains further away from the motor?

The only thing you have to worry abut is the chain to sled rubbing against the pinned end of chain when the sled is in the top right or left extremes. This cause wobbly cuts for me until I noticed it. I worked out that 12" from end of top beam and 1/2" from top of top beam was safe on my frame (same as yours).

If you are buying a new bungee then you might consider doing an alternative tension design. I saw a good idea to run a closed loop of surgical tubing between the two gear cogs.

The above thread has loads of different designs. I have not tried any. I can say that the stock bungees on my frame cause slack chain in top left/right 1.5’ and in the bottom corners the tension is very high.

The advantage of counter weights is that you have a constant force on the chain, compared to the constantly changing force of bungees.
If you turn the sprocket by hand left and right you will feel a backlash. The reason why we are not visibly seeing it is because the weight of the sled has more force on the sled side. Making a bungee strong enough to keep the chains across the top beam might introduce some of that backlash when cutting low on the sheet.

You only need starting with 2kg/~4.4 lbs as weight (I use plastic bottles with water) on each chain.
I’ve proven that it’s possible with the stock material, but there are far better engineered here on the Forum.