May 31, 2017 at 5:31 pm #34870
Wayne A HogueParticipant
After seeing this http://www.maslowcnc.com/ It got me thinking about the LowRider.
While the maslow looks promising, the hardware kit will not be available for a while(there is a waiting list) and they are still working on accuracy at the edges and corners. In the center they are getting +- 1/64 but drops to +- 1/16th as you move from the center edges.
The LowRider takes up so much space that is at a premium here. I could build it in a shipping container but that’s still a tight squeeze.
So I have been thinking of issues with tilying it on it side near vertical.
I think the Y and Z axis would be fine. Maybe some tweeking to the Y rollers to keep it aligned.
The X axis is another story. Gravity working for us in one direction and against us in the other. Belts will want to stretch and bigger nema may be necessary.
the stretching belt could be over come by using bicycle chain for the x axis like the maslow. Maybe a pair of nema 23 to drive it.
Anyone have any thoughts?
BTW the lowrider does not come up on google search for 4×8 router at least with several searches I have done. I remember a similar project a few years ago maybe 2014 but have not been able to locate it again.May 31, 2017 at 5:44 pm #34871
We all talked about this in the beginning of me designing it. I think it could be stood up at some sort of tilt, belts being the vertical axis. The belts are not going to stretch they are rated at something like 140lbs normal load each. Chain is not a good option it has much more backlash than belt.
I would like to try a tilted milling job but for me vertical space is more of a challenge than horizontal. It does get in the way but I now have a giant work table and can easily store all my other tools under it.
As for the goole thing until someone writes it up somewhere the rankings will always be pretty low. That is a foreign language to me. Last time I searched “3d printer” besides the paid ads the mpcnc was the first actual machine to be on the page over any other actual 3d printer…. Go figure.May 31, 2017 at 6:42 pm #34887
Dui, ni shuo de duiParticipant
If space is an issue, couldn’t you just use a foldable table?
You just need an old ping pong table, add a few wood layers to make a flat surface, widen it a little so that the rollers won’t hit the legs and it should be all right.
This way you can have a large machine when you need to , and save space when you don’t.June 1, 2017 at 5:13 am #34908
Counter-weights are the answer to your problem.
Mount pulleys at the top of the X-axis.
Weight the entire Y gantry and make two weights that add up to the total.
Run a cable from the top of the Y gantry on each side up over the pulley and attach the weights.
The weights will counter the effect of gravity by causing opposite pull in both directions.
You may need larger stepper motors on the X axis as you’ve now basically doubled your Y gantry weight.
The hard part will be figuring out a way of loading up an entire sheet of wood onto the machine. The floor will be in your way on one side and probably a ceiling on the other. Maybe figure out some way of hinging the Y axis so that you can swing it up out of the way or something.June 5, 2017 at 10:31 am #35152
For the pulleys, I imagine you wouldn’t want to use a single pulley for the counter-weight. The weight on a single pulley would likely limit your cutting height because the counter-weight would either hit the floor or the pulley before your cutting limits are reached.
A block and tackle would be a simple solution. Depending on the mechanical advantage, the counter-weight would only move a fraction of the distance that the gantry moves. The downside is that you have to use proportionally more weight to balance the weight of the cnc assembly. As long as your frame is sturdy and built well, that extra weight shouldn’t matter though.June 5, 2017 at 2:46 pm #35165
The problem with hanging weights is now you have a couple pendulums hanging off your machine. They will swing, and will cause issues.
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