Build or Buy Table?

For the MK2 I purchased earlier this year, I put my totally amateur woodworking skills to the test and built a 4 x 8 MDF topped mega-monster CNC router table. I have since then learned that MDF sags, my table is huge, and pieces of wood from Lowe’s like to twist and bend. I’m having issues with my CNC’s alignment and consistent cutting, I believe it’s due to my table moving on me. I’m contemplating building a new table OR I’m seeing all of these nice solid hardwood kitchen tables that people are basically giving away on Facebook Marketplace. Is there any downside to getting one of these tables that already meet the size requirements for the MK2 and just repurposing it for my CNC router? The cost of MDF/Plywood and lumber alone is more than most of what people are asking for on Marketplace and if I can be completely honest, I’m just not looking to build another table right now, I’d rather just purchase one and get to CNC’ing.

Appreciate all feedback,
Thanks, Tanner

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Hey Tanner,

Oh my, that would be a waste of what I find beautiful table. It looks stirdy enough, but yeah, it will work on ya. I have my machine mounted on a separate MDF slab that is not mechanically connected to my table. I could move the machine in working order off my table if needed. On top of that, I have a separate wasteboard that I can use if I need to work flat. Mostly, I just flatten the project and don’t need the table to be too straight. But if I really need to, I can have it in no time.

You might want to look into the secondary wasteboard direction before discarding that lovely table you have built.

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I’m having trouble with my gantry’s aligning and v wheels connecting to the axis rails.
because the table is so big and made from one giant piece of MDF, it has waves throughout it’s surface that I believe are causing alignment issues with the axes, compounding into even deeper issues when it comes to cutting. Example, my Z gantry has high and low points across the X-axis rail where the bottom v wheels connect, because I have to leave the eccentric nuts open to the loosest part of the axis, it causes it to sag forward in other spots where the bottom v wheels no longer have a snug fit. I’ve flattened my wasteboards and squared the machine, problem is that the hills and valleys in my MDF top are causing it to mess up in other places and ruin my cuts. Only thing I can think to do is dismantle and rebuild a better table with a truly flat top.

Hence, I absolutely don’t want to build another table from scratch lol.

What happens when you unscrew the tabletop from the table? Will that make it jump back into a more workable form?

If so, might you be able to support your MDF slab with a good set of beams beneath the table?

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@Tpoole1988 Hello Tanner! I concur with @Spamming_Eddie, that is a beautiful design you have! I also built a table from scratch. My Laminated Plywood Bench as many of us here have done! Don’t get me wrong, I’ve struggled with consistency issues as well. Have you flattened the spoil board? I did that and it GREATLY improved my carving. Then, still not being totally happy with the “quality” of my carving, I began to flatten the work piece to my cnc machine. Makes one heck of a mess, but the quality of the carves are superb!

If I were you, I’d tinker with what you have. A dining room table, while not a bad idea, will not be more sturdy than what you already have.

Heck, the majority of us are amateur woodworkers. When my dad wanted me to learn woodworking (he was a master carpenter), I was too busy drinking and chasing women.:joy::rofl::sweat_smile:. All joking aside, one of my major regrets in life. The school of hard knocks is much more difficult.
Bounce ideas off of us, we will get you there sir! Take care and continue to post your journey here!

Hey @Spamming_Eddie just a quick comment. I love your gantry you made there! Does it move as your machine moves? Don’t want to hi jack the thread, but like that design!

Hey Jake,

The gantry you see—a miracle you could see it for what it is with all the mess in the picture—is actually the turnable connection for me to be able to pull the table off the wall to be able to have more space behind the mill for longer projects.

And it’s also the pivot point on which I can turn the table from the wall into the garage when I need all the space I can get. I can run stuff through the door into the office if needed. Or if I need to get to the mill’s backside.

The turnable gantry is mounted on an old kitchen table I used as a work table and wood storage.

This was my initial setup; it has evolved since but is still possible, if I make the space and relay some cables, to turn around. Mostly, it just sits at the wall… quiet… waiting…

Thanks guys, I think I will try to work something out with my current setup. I certainly didn’t do myself any favors with the lack of support I put underneath the table. Being the novice that I am, what would be the best way to brace the bottom side of the table? The top frame is super basic, just 2x4 around the edge, screwed into the 4x4’s in the middle and on each corner, and finally 1 2x4 running underneath the center of the table connecting the 4x4’s that are just to the left of the CNC. The 8 foot 2x4 that runs along the face of the “front” of the table had serious sag to it in the center of my CNC, so I added in the additional 4x4 you see in the picture. I’ve surface my spoilboard, it’s flat and I’ve used a bubble level tool to ensure that every single spot on the spoilboard has the same tilt/angle (the entire spoilboard has a slight lean, but it’s consistent the whole way across). So if I screw the top off and pull the machine off, how/what/where do I add braces?

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Hey Tanner,
Personally, I’m a huge fan of laminating lumber. Anything from plywood to dimensional lumber, I like to double them up and use a good bed of a decent woodworking glue.

This is how I did mine. Overkill? Possibly. I utilized pocket hole joinery to secure my top which was 3/4” plywood to the frame. Then I put my MDF on top of that in order to secure my machine. I used a 4’ level to ensure my support pieces were perfectly flat before placing my plywood top on it. If you haven’t already done it, I encourage you to have a look here on the forum a thread specifically about building a bench for the Long Mill. Everyone designed theirs a little differently. My attempt was prior to even getting my machine. I do have casters on my bench, but the retract so my legs rest firmly on the concrete. No rock at all. Also no twisting.

So I would carefully remove your LongMill and the material for your top and install another few 2x4’s on each side of the existing center one and then install blocking between them. You will be pleasantly pleased with how much more stable your bed will become. You could add from below your machine, but I prefer to work at chest height. If you don’t mind crawling under the top, then my all means do it. The alternation of blocking allows you to screw through the side of the lumber into the end of the blocking.

I hope this helps! It will get much better, honest!

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thanks for the advice! one question, with the 2x4’s that run around the frame already sagging, will they just bring down my boxed 2x4 connections, or will those connected boxes be a “greater than the sum of their parts” type force that will elevate and level the frame areas that are bowing?

Could you add an additional straight 2x4 to the inside of the outer 2x4 and bring the outer one back into place? Not sure if I’m making sense. The Xoriginal 2x4 is sagging if I read this correctly. Adding another one on the back side to bring your original one to level? I’ll stop now, if that doesn’t make sense, I tend to be a visual person. Let me know and I’ll draw something out. It’s been a long day! We are here for you Tanner! Also something I meant to ask about earlier, did you nail or screw your lumber to your 4x4’s? Decent screws make a lot of difference too.

Following you 100%. Completely forgot, but I also have a 2x4 that runs front to back underneath the middle of the table, dead center, under the CNC. That is also adding weight and creating sag. I’m actually at the lake on a vacation with the family for the next few days, but when I get home I will take a picture to give you an idea.

There are many ways to support. I have kept my setup as versatile as I possibly could. My primary tabletop is a standard slab of meranti 22mm (light blue). If it needs replacement, I only have to slap a new one on there.

My wasteboard (orange) where the mill is mounted is MDF 22mm with a piece ripped off so I can slide it left or right on the meranti top (I didn’t decide where I wanted the mill to sit). Doing it this way I never have to. I am thinking of milling some holes on the front of the wasteboard so I can mill projects that are larger than the Z space available. I can slide the mill over the edge of my table and have the project stick through the hole. But that is another update still to come.

The outline of the table (brown) is done with 2x4, slightly larger on the inside than the meranti tabletop.

The support structure (green) is 22 mm below the outline to have the meranti slab level with the outlining construction.

Both the Meranti tabletop and the machine wasteboard are in no way mechanically connected to the table and are free to expand or shrink in any direction.

It would be cool if Sienci sold the AltMill table as a stand alone item. I know they’re probably not in the mood to spin off a part of the AltMill as they’re in the middle of ramping up production for their brand new product.

But I can dream. :slight_smile: