Has anyone built a 'LongerMill'?

Hi everyone.

Just wondering if anyone has extended the Y Axis on their longmill.

I have a few projects in mind where it would be an advantage to have the Y axis reach to 48". I won’t able to go diagonal and would prefer not to tile. I read the post Things to consider when making a longer LongMill | Sienci Labs and I have an idea of the changes and limitations. It seems the l main caveat to going longer on the Y is whip on the lead screws.

If my math is correct adding 18" would require a 1487mm lead screw and 1500mm appears to be commonly available. I should be able to get longer 2x2 angle locally, and either 3d print or purchase from sienci the additional middle feet and drag chain, and I could use the extra wiring available on the left y axis motor to patch in an extension on the z axis motor cable. Am I missing anything?

Any chance of an official 30x48 Sienci upgrade kit?

Oh, I do own a LongMill 30x30 v4 bought Dec 2020. Just want to go a little longer

@starckie Welcome to the group, Scott. You will find it a great place to ask questions, pose solutions and post pics of your projects.

I re-read the document that you linked to, just to remind myself of its contents. The technicians at Sienci will be better able to discuss all the issues with making a LongerMill. My take away, FWIW, from that resource document, is that the least of your concerns will be sourcing longer lead screws, longer rails, longer cabling and additional feet.

Longer axes mean greater whip potential if you don’t go with heavier lead screws. Heavier lead screws mean bigger bearings and different couplers and feet to hold them. The document also talks about likely wanting to increase speeds (not a necessity). Increased speeds likely mean bigger steppers. Bigger steppers need more power. Greater speeds also increase the potential for lead screw whipping.

I’m sure that all of this sounds very negative. Clearly, what you want to do can be done. However, a lot of emphasis in that document is on why the LongMill size is it is. These guys are engineers and had the experience of the Mill One to learn from.

All that preaching done, I still wish you good luck with your project. Please post your results.

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