Cutting a 5x5 square tube

[Joe Jones]

One thing is certain. No matter how big a shop is, it will NEVER be enough room!

Joe

[AndyZ]

Torch Extension.jpg

Hi Folks, I finally found the time (I Retired) to tinker a bit more on this idea. Here is a work in progress, but it did make the cut on this 5X5 tube outside of the table. I'm relooking at a few of the ideas that you guys shared. I'll be reworking this as the magnetic base isn't strong enough to manage the additional weight as it jostles around especially during initialization.

[Joe Jones]

Torch Extension.jpgHi Folks, I finally found the time (I Retired) to tinker a bit more on this idea. Here is a work in progress, but it did make the cut on this 5X5 tube outside of the table. I'm relooking at a few of the ideas that you guys shared. I'll be reworking this as the magnetic base isn't strong enough to manage the additional weight as it jostles around especially during initialization.

That is a good start. Remember that a counterbalance will make the whole process more stable. The Z motor CAN lift the weight, and with a counterbalance on the back side of the backing plate, you will virtually eliminate the goose pecking action of the torch tip. The counterbalance must be attached to the backing plate and move up and down with the the backing plate and the extended torch mount. The counterbalance could be a tin cup in which you pour a handful of 1/4-20 hex nuts for weight. Then the whole thing will move straight up and down, like the cross member of a ' T ' I would create a flat 14 gauge plate beneath the Z motor 4-point mount, and attach the counterbalance to the back side of that plate.

Joe

[rdj357]

Good start there Andy! I think you're on the right track in that you could make your extension so that you moved both pieces of the magnetic mount out to the end of the unistrut by making a piece that would bolt into the carriage torch holder.

As for weight and balance, too much weight on the gantry will sag it in the rails and cause a lot of backlash and trouble. Because it's going to be a dedicated spot off the end of the table, maybe a good idea would be a support from above to the torch cable with a spring to allow movement. So the cantilevered weight of the torch could be transferred to somewhere other than the gantry.

[Joe Jones]

A counterbalance is not about weight. It is about leverage. I learned this while riding a teeter-totter! In a doctor's office, I observed how moving a small brass weight an inch or two could compensate for 50 pounds of weight on the scale. LEVERAGE.

A simple one pound weight on a leveraged arm will serve as a counterbalance. It does not require anything near the weight that would cause the gantry to sag. You only need enough counterbalance weight to compensate for the forward tilt force being applied to the carriage by the extended arm with the torch mounted to the end.

Joe

[weldguy]

Hi Folks, I finally found the time (I Retired) to tinker a bit more on this idea. Here is a work in progress, but it did make the cut on this 5X5 tube outside of the table. I'm relooking at a few of the ideas that you guys shared. I'll be reworking this as the magnetic base isn't strong enough to manage the additional weight as it jostles around especially during initialization.

Pretty cool

[rdj357]

A counterbalance is not about weight. It is about leverage. I learned this while riding a teeter-totter! In a doctor's office, I observed how moving a small brass weight an inch or two could compensate for 50 pounds of weight on the scale. LEVERAGE.

A simple one pound weight on a leveraged arm will serve as a counterbalance. It does not require anything near the weight that would cause the gantry to sag. You only need enough counterbalance weight to compensate for the forward tilt force being applied to the carriage by the extended arm with the torch mounted to the end.

Joe

[tinspark]

Torch Extension.jpgHi Folks, I finally found the time (I Retired) to tinker a bit more on this idea. Here is a work in progress, but it did make the cut on this 5X5 tube outside of the table. I'm relooking at a few of the ideas that you guys shared. I'll be reworking this as the magnetic base isn't strong enough to manage the additional weight as it jostles around especially during initialization.

Thats a great Idea! Thanks for the share

[adbuch]

It looks like you achieved a pretty nice cut with your setup as-is. You've got those bungee cords attached to the extension to help to keep if from breaking free of the magnetic base. I agree with Robert - just bolt your extension directly to your Z bracket and move the entire magnetic mount out to the end of your extension. You could use your bungee cords connected from the torch end of your extension to go an overhead cable or bracket so as to apply some upward force to counteract the cantilevered weight of the bracket/torch/cables, but I think the gantry is stiff enough that this step may be optional. Just keep it as simple as possible.

David