I was adding items from the DIY Kit Mechanical Equipment Equivalent Parts list and I was looking to see what the recommended length was and couldn’t find it. How much chain do I need for the usual 4x8 setup? the closest length that equals the $100 mentioned at the bottom was 19ft ($97.66).
The original length is 11ft on each side. There is currently a tendency to go wider with the motors so more then 12ft is needed.
Thank you, this information is helpful. I just didn’t want to order a length that was going to be too short.
The 5 meters ~16.4ft from china including shipping look interesting but I’ve not checked the overall measurements.
Regarding the 12’ beam, I have got mine up and running…
At present, it is pretty accurate…
but there is always room for improvement.
To determine the chain length needed for the 12’ system, first the height of the beam from the workpiece must be determined. Retaining the same geometry as the 10’ stock “screw & glue” design raised the beam on my machine, with its 9" h bottom ledge and the addition of wheels, from about 17.5" from the top of the workpiece, to about 27.5", or 94" from the floor. In my shop it is important to be able to wheel my Maslow through an 8’ high door, so I set the beam a little lower at 90" to accomodate the motors and any slack chain management schemes I might want to try. This changed the “top of workpiece measurement to about 23.5”. Regarding the slack chain, since the cutting area remains the same, and my approximately 32" slack to 72" streched bungee worked really well on the original configuration, my plan was to pretty much replicate the same area as the original design for chain management. All of this is to say that I ended up with a 13’ (156") chain length on each side. As there is a bit more chain weight, tying a knot in the bungee was enough to increase the tension to a nice balance. Driving the sled around the parimeter with about 2" for safety on the ends, and right on the line top and bottom, the bungee hook goes maybe an inch too far on each side. So I will probably add 4" of chain to each slack end.
The sled now is rock solid in the bottom corners, with enough pull to the outside to counteract any small hang-ups on the work surface, or the tension of the dust collection hose. The machine cut the benchmark pattern without a hitch. I highly recommend this upgrade.
@Dustcloud, are you saying that the 12’ width will require you to shorten your bungee by 4" on each side so the hook doesn’t hit the sprocket when the sled is down to the bottom corner?
If I understand correctly, then your original " 32" slack to 72" stretched " becomes 24" slack to 64" stretched… ?
With the knot in the bungee, is it currently closer to 26" now ?
(Bungee an inch too long / chain an inch too short)
Thanks for sharing this post - it really helps !
Regarding the 4" addition to my chains, keep in mind that the “tail” ends are doubled over the take-up cog, so it would add only 2" to each side. I am working from memory on the bungee length, as the machine lives 200 miles away from my city house. Also, the bungee has been on the machine for several mounths, so it may have streached a little. Keep in mind that all of this is dependant on how the machine is built. I will be up there Tuesday and I can give you precise measurements then.
Happy Labor Day!.