Thick vs Thin fixture tables? What’s your thoughts on this?

[Fireball_Jason]

I recently found this article and I thought it was an interesting topic.

Welding and Fabrication Table Top Thickness - 1/4″ vs 3/8″

I thought it be great to have a discussion about it. This topic gets brought up a lot at trade shows.

Let me start off with the excessive clamp loading. Let me just say this, if it can happen it will. Not everyone is going to use the correct clamp for the table top, we can talk about that topic later, but If the clamp goes in the hole it’s going to get used. What’s your experience? Have you distorted a table hole before? I’ll see if I can find the original film that was the article referenced. Will take a closer look at the hole.
I need everyone to remember, I didn’t have a table in production at the time the video was made. I had an open mind and tried to not be biased in any way. I just know how tools are going to be used in the workplace and wanted to replicate a worst case condition.
Jason

[johnp]

Hey @Fireball_Jason ! John P. here. One of our mutual customers shared your discussion with me!

A couple quick points:

• Just to second what you said, you indeed were NOT making tables when you made that video, or when I wrote that article. And your video is a fantastic, and fair, assessment with all the info you had available to you. It’s what inspired me to put some thought and research into all this. Furthermore, you always approach topics you’re investigating with an open mind and a well reasoned approach. Thanks for the effort you put into that for us!
• Now that you’re producing tables, they are amazing. I saw them at Fabtech and would have said Hi, but you’re always swamped with fans.

I always think this topic is fascinating because valid arguments can be made from different perspectives.

I’m sure many people are familiar with the old phrase, “No one ever got fired for hiring IBM.” The reference being that when you buy the absolute best no one can accuse you of doing the wrong thing. And one could argue this applies to everything (almost). If we were all billionaires, what the heck… give me a Blueco! It’s just money. And since you allegedly can’t get anything better we can cross that off the list if anything goes wrong.

On the other end of the spectrum, for an individual or small business doing work with 1/8" or 1/4" tolerances, it might be irresponsible to spend exorbitantly when funds might be better deployed elsewhere.

I think it’s great that there are a variety of options to meet different needs. If I were to oversimplify my view of the market it would look something like this. (Excuse the white board sketch.)

Perhaps I can also share three thoughts tangentially related to this topic.

Variable Build Quality
Tables that utilize material removal processes, such as milling or grinding, should always have an edge when it comes to consistency. Assuming the machines doing the work are cared for, calibrated, and professionally operated, the output should be remarkably consitent.

Tables that are fabricated from laser cut parts are subject to far more risk factors including the quality of the material, the consistency of the thickness of the material, and the skill and processes employed with their assembly.

Building really flat tables is MUCH harder than the other method, so it’s a more an experienced-labor intensive process. The cost advantages come from material savings which can offset some of that labor, combined with the speed of laser cutting compared to milling.

Strength and Durability
Clearly more and thicker is going to be stronger, all other things being equal! But the question is, how strong is enough? From my perspective the key is to have enough strength that whatever you put on the surface doesn’t cause more deflection than is acceptable for the tolerances required.

So if you need to maintain 1" of tolerance, the weight on the table can’t cause it to sag more than that or you simply can’t get the job done.

For people who are only putting a few hundred pounds on the surface, all of these tables are fine. But if you’re going to put 4,000lbs… well, now we need to understand how the table is going to behave before we can say if it’s appropriate.

Flatness
This is again an area where material removal processes have a huge advantage. It kind of doesn’t matter what the material looks like before, because the after is always going to be the same.

Conversely, fabricated tables have to fight the natural tendency of the material to curve. You have to worry about specs of dirt getting between parts, or burs on the edges of material. And many other things.

When done correctly, the results can be surprisingly good. For example, here’s a scan from our $100k Verisurf laser system of one of our 70"x140" tables. Personally, I’m super impressed by how flat we got it. You can see one little problem area on the end, but even that is pretty darn good, plus it’s down, not up, which is at least better.

Anyway, I hope this added a little value. I can’t wait to see what others have to say. I’m always anxious to learn how we can all do things better!

[Fireball_Jason]

Hey Jon, I have a few questions that I hope you can answer.

I noticed that you build and fabricate your fixture table off of a competitors table . Here’s the photo I’m referencing.

How come you don’t use your own tables for assembly?

How come the tables that you make don’t have chamfered holes?

What happens if the thin table top gets heat soaked in one area?

Why do you mix match table and tooling from another company?

Is a nut and bolt the only option you have to hold fixtures to the table?

[johnp]

Hey @Fireball_Jason, great questions. Let me take them in order…

How come you don’t use your own tables for assembly?

Short answer: since we’re laser cutting and fabricating our tables, I like to think of it as if we are trying to build a perfect copy of a table that already has a known surface. Those Siegmund tables were milled, and we measured them and they were very flat. So we use them kind of as support to keep our tables as flat as possible while we build them.

Longer answer: the Siegmund tables were one of the first things we implemented to improve our repeatability. They work pretty well as a crutch. We have plates mounted to the floor, and the leveling feet for those tables mounted to the plates so that once we leveled them as good as they can get, they don’t move when the table is bumped or whatever.

At this point, we have added some of our own tables, which again we’ve measured and leveled and know they are very flat. But since we spent the money on the Siegmunds and it ain’t broke…

How come the tables that you make don’t have chamfered holes?

This is simply a function of the process. All of our holes are cut on the laser. So of course it simply cuts a cylindrical shape out. Chamfering would be a secondary operation which would add cost, and we’re trying to keep the price point down so these tables are a viable option to folks who don’t require something absolutely flatter and stronger.

By the way, I love the look and feel of chamfered holes. But I’m not aware of any performance improvement with them. Is there a reason you asked other than curiosity?

What happens if the thin table top gets heat soaked in one area?

Well, this is a great question. At a micro level I truly don’t know. It would be interesting if I used our laser to measure a section, heat it as much as possible, and measure it again.

Anecdotally, I can tell you about a time we had something bolted to one of our shop table tops and we picked it up with a forklift. The bolt deformed the hole a little, pulling it up around 1/8". I took an oxy torch with a rosebud tip and tried like hell to heat it up so I could knock it down gently with a hammer. With direct flame on it from the torch I couldn’t get it hotter than a dull red glow in a small area. So I think the entire top acts as a heat sink.

But there is another important technique that I personally use and recommend. I like to elevate the work off the surface of the table. If you have some precision rests you can just put the parts on those and not affect the overall flatness. And this allows you to keep heat off the surface, as well as giving you some room to do downhill welds on parts without running into the table.

Why do you mix match table and tooling from another company?

Again, when all this got started I was retired from other stuff and just building tables for people pretty much for fun. We began selling Stronghand tools purely as a service to people who needed tools to go with the tables. We’ve been growing so rapidly over the last few years that we’ve been fine working with them to supply the tooling, but in the not too distant future we’ll be releasing our own tooling.

Oh, also I think a benefit of all the tables with standard 16mm holes is that you can mix and match brands of tooling and they should all work.

Is a nut and bolt the only option you have to hold fixtures to the table?

Well, there are several ways to fixture things to the tables:

• There are vertical clamps that drop into the holes and clamp downwards, like the one you used in your video test I think.
• There are some other ones that kind of look like half a C clamp which reach forward and clamp down.
• You can certainly use a bolt and reach under the table to add a nut, but there are also little magnetic accessories called a threaded hole adapter which you can just pop under the table and then bolt into.

I feel like I’m forgetting some other options, but the point is there are multiple ways to temporarily, or “permanently” affix things to the surface.

Hopefully these answers make sense. And if anyone has any suggestions on how we can improve our processes or products I hope they’ll respond with comments and ideas! We’ve got a really great team of folks over here who truly care about what they’re doing, and we want to always do it better if we can!

[some_rando]

Let me first state that I’m a hobbyist repairing or augmenting existing equipment and I hate doing work that’s lower quality than I can pay someone else for. I love working with metal, but I want to get a certain level of quality in my results with relative efficiency more.

I have two primary issues with anything under 3/8" thick: I’m not building art and I’m generally building things that need to fit tightly against something pre-existing so they don’t vibrate and cause damage (great example would be bolt ons that carry weight on off-road bumpers, don’t want them slowly wallowing out bolt holes or chipping powder-coat like an inefficient needle scaler). The second issue I’ve got is that I have no idea what I’ll be working on before I start a project and some of those items might be very heavy. It’s not to say that those thin tables don’t have a place, but they’re pretty awful between the clamp load causing hole distortion and the fact that the fixture pegs don’t have as much material to bind against to fight angular deflection from perpendicular to the surface.

I don’t have a heavy-duty cast table because it didn’t fit in the budget and I likely wouldn’t be able to physically get it to my place, but I also have a pretty decent table and the company I got it from was incredibly helpful with my situation. It was laser cut with slightly undersized holes which I reamed to final dimension. It was a pain to get done, but it was absolutely worth it as every hole is exactly .625" and not conical in shape.

If I was starting to learn to weld again I’d buy that Titanium fixture table (or two and stack the tops) since it’s way better than the dirt-cheap 20ga sheet metal tables for clamping, but I wouldn’t pretend it’s as good as a 8’x4’ Fireball or even what I’ve got.

IMO for the price of many of the 1/4" tables I don’t think they’re cheap enough to be worth buying in comparison to saving a bit more and getting something just a little bit heavier.

I’m not even going to start in on the fact that most of the cheap tables are made in China and aren’t even a full 1/4" since they’re using metric plates…