Hello,
I am a newbie here. I have a LR4 and I constructing its table.
What’s the largest X axis anyone has built on an LR4? I know sagging is an issue.
Thank you for your time.
How long is your Y axis going to be?
Sagging is not the issue, rigidity is. The X axis NEEDS to be the shorter axis for a dramatically faster machine. The longer your X the slower your machine.
What materials do you plan on cutting?
The largest we had was someone cutting 30’x8’ sheets for a dome of some sort if I remember right.
Y will be 96" long
Material woud be 1/4" to 3/4” plastic
That is wild. did he have any issues? would you use aluminum struts or extra braces?
I cut consistently 4x8 acm sheets and extruded pvc sheets. Neved had sagging issues with my build iuse mdf with glue as sealant. Ultra conservative Z rapids/plunge. Perfect and clean cuts all the time using cheapo bits
I built a very large LR4 that runs a drag knife. It would be unsuitable for running a trim router with the size of that machine’s X axis.
X is the limiting factor, then above 10 feet of Y you have to figure out how to join tubes.
Standard length in the EU for the suppliers is 6m, so you still have some breathing room. 
But I’ve also just joined them with a two-sided plug. 
In my country the y axis can be had at 19 feet for under 8usd. 
My goal is to have the table 6 ft x 8 ft. It sounds like it is doable. I want to run a makita router.
To do what with? 6 feet of X axis is oversize for many uses.
You are getting 6’ wide material?
I don’t know your material off hand, but my table was roughly 5’x10’ with full sheet mdf and a tiny bit extra cutting area. I’m in the process of shrinking it down because having that much space taken up was a waste. I only ever did one cut that needed a machine that big, and it was the strut plates for itself. The machine can do it, just know there are downsides.
Off I was doing boat foam, I might have tried a slightly bigger machine… but it’s all about end user needs
Melamine comes in 7’x9’ in my country, we also have some other oversized materials. I actually dont work with them because the investment in a machine that is capable of 7’ wide has a really slow roi. We process the melamine in a saw table
I was thinking I would like the option to cut plastic or mdf that is oversized than just the standard size;
The machine can do it, just know there are downsides.
what were they ? You mentioned space.
Also, did you have any problems with accuracy at those dimensions ?
The larger you make the machine the slower you have to cut to keep the same accuracy.
For example “I just don’t want to break down full sheets, but only cut small things” would be a horrible reason to build it bigger. The only common reason to build a big machine is to cut big parts.
I agree with your example. I have some ideas but to be honest they are so far down the road. I need to get this thing rolling and built out before I’m there yet.
Ryan answered you.
But to expand from my own experience…
First is the weight of the material. I can lift mdf no problem. But to gently set it in the center of a machine is a completely different story. I built a steel structure under mine so I could rest the mdf on the end of the machine and slide it in without racking the table in the process. It still wasn’t fun. On the end of the machine are wo printed parts holding the z belts. I have 2 full sets of back ups ready to go because I’ve broken them enough trying to load such a big heavy awkward piece of material
Working with thinner material was a game of clamping forces. You can’t just throw ¼ plywood up there and screw the corners. Wood flexes and is almost never straight and flat. The longer the material the more the center will bow and vibrate. So i was constantly looking for where I could safely hold it down. Not a huge deal, but it did turn into a game of following the machine and putting screws where it just cut out or taking them out of where it was going to be going next. A smaller machine doesn’t get rid of this, but it’s much less pronounced.
Ryan mentioned speed and accuracy. I actually didn’t find this to be an issue because I had never run a machine before this one. I just thought it was cool that it could do what it did. But the numbers don’t lie and the more you look into it the more you realize you have given up. I just flattened my spoilboard on my shortened up machine, but i can already tell the ability to hold the bit in place while working is much higher. I’m guessing the speeds i can hit now will make me feel like I wasted so much time. Especially because it turned out my material was full size but the parts I actually cut were never that big. I think the biggest parts I cut on the machine were the strut plates. Everything else i did would have my ¼ sheet machine.
Anyone ever tried running a vacuum hold-down in reverse to have it act like a giant air hockey table?