Hey Chris and Taylor, I'm an AIADO alumni who's looking to modify the LILCNC plans and I'm seeing that the dremel tool seems to occupy only 2/3 of the Z-Sled. Is there a reason for this or can I remove the space occupied by the Z-Sled Front piece? I'd have to shorten the Z-Rail Bearings and maybe lower the position of the Z-Rail Bearing Trap but it looks like I'd gain more cutting height from this.
-Ming
Can I also reduce the width of the Z-Sled?
Nevermind I see that the space is needed for the interlocking t-bolt joints.
@Ming,
The Z sled is a great target for redesign. As you've pointed out, there are many opportunities to save space (and gain travel). You might want to consider permanently attaching some panels with glue - this will reduce the need for bulky tab/slot fixtures.
Is there anything to hold the Z-Rail bearing assemblies to the Z-Sled besides a tight fit? I see that the X-Rail bearing assemblies are bracketed in place by trap and tensioner panels but there doesn't appear to be any for the Z or Y axis.
Also a related question: why do the Y-Rail bearing assemblies stick out so far from the Vertical Braces?
Ming, great questions (good to hear from you, btw).
It's pretty much friction holding the Z-Rail bearing assemblies to the Z-Sled. Really the Z-sled just needs to stay aligned vertically; the acme screw does all the work in that part of the gantry.
One alternative we're going to look at in an upcoming redesign is to use bushings wrapped around steel rod. Something like this:
This will eliminate lots of bulk in the Z-cart as well as all the extra parts required for the skate bearing assemblies.
To answer your other question regarding the long Y-Rail bearing assemblies: we tried to make them shorter, but found that the gantry would rack pretty substantially, since it's only held down by gravity. That's another thing we're planning to address in V2, getting the Y-bearings trapped somehow so they're more stable.
Thanks for the information Chris! I was thinking of linear bearing blocks too after seeing it in Sly's build. Sly used VXB, which looks like a good choice.
Right now I'm trying to contact VXB in regards to some measurements for the 12mm bearing blocks because the Rhino model I built from the listed measurements looks like a flattened version of the actual bearing block. If I'm reading the measurements on that page correctly, the block should be 28mm tall and 42mm wide. Thus the height should be 2/3 of the width but the photos don't convey those proportions.
I'm emailing VXB about the dimensions and hoping to have a reply soon. Hopefully I did something stupid and that the listed dimensions are right (instead of me being right and being therefore unable to trust any of the measurements given on the site).
On a tangent, I am currently planning on making a highly modified LIL CNC. I'd like to include stepper motor dampers to increase IPM, an Arduino replacement for serial ports, a dust shoe, a cyclone dust trap.
In addition I'm planning on switching out the timing belts for leadscrews or racks & pinion. I feel like I'd end up screwing up the timing belts by tightening them to different tensions. I will update you on design modifications as I make them.
You must log in to post.
