Welding Table Tabs Tolerances

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Plasma-art
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Welding Table Tabs Tolerances

Post by Plasma-art »

working on designing a welding table and fixtures and at the point i am drawing in the welding tabs and slots.
in this case its 6mm (0,23622 inch) thick sheet and the tabs are 30mm long.
both sides 0.5mm (0,02 inch) so a total of 1mm (0.04 inch) clearance.
the holes on the corners are 4mm diameter so should cut ok?
would this be enough to cut on a plasma or is it to tight?
tab.PNG
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Re: welding tabs tolerances

Post by adbuch »

If your table is tight and you cut some samples first to adjust your kerf width, then I think the 0.040" size differential will be fine. Is this to be welded?
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Re: welding tabs tolerances

Post by Plasma-art »

Yes, this is to be MIG welded.
No table yet, waiting for parts but preparing alot of drawings.
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Re: welding tabs tolerances

Post by kicktillmonday »

Are guys using plasma tables to cut parts to build welding tables like this?

I would have thought that with the tighter tolerances required for a good build, and the plasma bevel on the cut edge's which cannot always be eliminated that plasma was just not good enough for this type of thing.
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Re: welding tabs tolerances

Post by Plasma-art »

There are plenty of examples of plasma cut welding tables, Tay from Lift arc studios on youtube cut one from Maker table files for example.
Yes the machine needs to be dialed in and you might need to do some clean up but there is no reason not to do it.
It all depends on the tolerance you want to try to achieve.
It's probably not going to be 0.1mm over a meter but 0.5mm per meter would be plenty for what I am trying to achieve.
It's also extremely difficult and very expensive to get a decent fab table in my country.
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Re: welding tabs tolerances

Post by kicktillmonday »

Plasma-art wrote: Fri Sep 16, 2022 1:00 pm There are plenty of examples of plasma cut welding tables, Tay from Lift arc studios on youtube cut one from Maker table files for example.
Yes the machine needs to be dialed in and you might need to do some clean up but there is no reason not to do it.
It all depends on the tolerance you want to try to achieve.
It's probably not going to be 0.1mm over a meter but 0.5mm per meter would be plenty for what I am trying to achieve.
It's also extremely difficult and very expensive to get a decent fab table in my country.
Thanks, I will go check out that guys build on Youtube, very interested now :Like :Like
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Re: welding tabs tolerances

Post by adbuch »

Plasma-art wrote: Fri Sep 16, 2022 1:00 pm There are plenty of examples of plasma cut welding tables, Tay from Lift arc studios on youtube cut one from Maker table files for example.
Yes the machine needs to be dialed in and you might need to do some clean up but there is no reason not to do it.
It all depends on the tolerance you want to try to achieve.
It's probably not going to be 0.1mm over a meter but 0.5mm per meter would be plenty for what I am trying to achieve.
It's also extremely difficult and very expensive to get a decent fab table in my country.
What country are you in? I watched the Lift arc studios 5x10 table build video. It looks like they may have been using 1/4" thick material. They did mention that their finished table was bowed up in the middle (I think they said about 1/8" or so) and they were planning to install a lag bolt into the concrete floor and install a turnbuckle in an attempt to pull the center down so the top is relatively flat. With a smaller table, this may not be as much of a problem. Another consideration is the wall taper on the plasma cut holes. This may be ok for use as a welding table where the holes are only used for clamps. But for precision fixturing I would want the holes either laser cut or drilled with annular cutter as used with portable mag drills.

My welding table is made from a 1" thick x 3 ft. x 7 ft. steel remnant that I picked up at the local structural steel supplier years ago. It was an off cut from a much larger piece and basically a left over. I took a long straightedge to check for flatness when I picked it out. It has one 3/4" hole in the middle that I installed an eye bolt into to lift it out of the back of the truck. I think it weighs around 800 lbs. It has served me well for many years.
welding table.jpg
A few years ago I bought several of the Rhino Carts mobile fixturing stations from StongHand Tools. The tops are 30" x 48" x 5/8" thick machined flat on both sides. They have 5/8" id holes on 2" centers. They come with locking casters and leveling feet which makes it easy for them to be butted together and leveled out for a nice flat level surface - either 48" x 60" or 30" x 96" when joined together. They also came with some basic clamps and fixturing and I have added to that as I went along.

More photos of the Rhino Cart projects here.
https://photos.app.goo.gl/SsDsKC4MvY7FEAkU6
and here
https://photos.app.goo.gl/7xdUae3eoVWjbSrL7
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Re: welding tabs tolerances

Post by Plasma-art »

adbuch wrote: Sat Sep 17, 2022 2:49 am What country are you in? I watched the Lift arc studios 5x10 table build video. It looks like they may have been using 1/4" thick material. They did mention that their finished table was bowed up in the middle (I think they said about 1/8" or so) and they were planning to install a lag bolt into the concrete floor and install a turnbuckle in an attempt to pull the center down so the top is relatively flat. With a smaller table, this may not be as much of a problem.
I'm in the Netherlands, found supplier with long lead times and high prices for the tables plus they are imperial spacing and I want metric.

1/4 inch is a little thicker then 6mm but not by much, for me the next size up would be 8mm.
Not worried about any warping because I have a big cast iron table I can torque it down to at a local company that I can use when ever I want, that's the plan anyway.

Wouldnt mind a 30mm thick welding table but I cant handle the weight.
Would have to squeeze it around a corner while having it on end or take the roof off and hire a crane to lift it in :HaHa

For starting out I can live with a less then perfect fixture table with the work I am doing, it beats working on a wooden bench with a piece of sheetmetal ontop of it.
When i outgrow my space and have something bigger i do intend to invest in a bigger table.
for now I can not justify investing 3500k euro in a 3x3 foot table and another 1500k in tooling for it, rather spend that kind of money on a better plasma cutter.
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Re: welding tabs tolerances

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I have wanted to build a table at home for a while. I built a 4’x6’ table at work on top of a hydraulic lift table using a 1/2” plate and a mag drill with 5/8” annular cutter. Then I used 1” threaded rod and tapped the center of the rod for all of my bolts to fasten the plate to the table. I adjusted each nut on the threaded rod until the fixture table was completely flat. It is a good table, the only downside to this is I don’t have any side walls to clamp to. But it suits us well for what we do.
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Re: welding tabs tolerances

Post by adbuch »

Plasma-art wrote: Sat Sep 17, 2022 5:45 am
adbuch wrote: Sat Sep 17, 2022 2:49 am What country are you in? I watched the Lift arc studios 5x10 table build video. It looks like they may have been using 1/4" thick material. They did mention that their finished table was bowed up in the middle (I think they said about 1/8" or so) and they were planning to install a lag bolt into the concrete floor and install a turnbuckle in an attempt to pull the center down so the top is relatively flat. With a smaller table, this may not be as much of a problem.
I'm in the Netherlands, found supplier with long lead times and high prices for the tables plus they are imperial spacing and I want metric.

1/4 inch is a little thicker then 6mm but not by much, for me the next size up would be 8mm.
Not worried about any warping because I have a big cast iron table I can torque it down to at a local company that I can use when ever I want, that's the plan anyway.

Wouldnt mind a 30mm thick welding table but I cant handle the weight.
Would have to squeeze it around a corner while having it on end or take the roof off and hire a crane to lift it in :HaHa

For starting out I can live with a less then perfect fixture table with the work I am doing, it beats working on a wooden bench with a piece of sheetmetal ontop of it.
When i outgrow my space and have something bigger i do intend to invest in a bigger table.
for now I can not justify investing 3500k euro in a 3x3 foot table and another 1500k in tooling for it, rather spend that kind of money on a better plasma cutter.
OK - I checked your other posts and now I remember more about you. You are in the process of building a diy smaller size cnc plasma table with dimensions somewhere around 22" x 49" cutting area. I was not suggesting that you purchase or build something different than what you are already designing for your welding table - just showing some different ideas that might be of interest to others here.

My first "welding table" was a wooden bench with a sheet metal cover. Then later I moved up to a piece of 3/16" thick steel about 24" x 30" mounted to a steel stand. This worked great for smaller jobs for welding and layout/assembly for smaller projects. For what it sounds like you will be doing, I expect that a smaller table - maybe about the same dimensions as your plasma table - would be perfectly fine. And I don't think you necessarily need all the holes on a 2" grid, but maybe just a few holes out in the middle for post clamps. The main thing is that your surface is flat enough for your particular needs. You can always use small shims to level your assembly out on the table before welding if need be.

Just curious - what is 3500K euro? Is that different than 3500 euro or about the same as $3500 US? But in any case, I agree that is a large cost compared to a diy approach. I know that Tom has build a medium size welding/fixturing table and much of his own tooling. Perhaps he will chime in here and show us some photos.

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Re: welding tabs tolerances

Post by adbuch »

SRdesign wrote: Sat Sep 17, 2022 8:40 am I have wanted to build a table at home for a while. I built a 4’x6’ table at work on top of a hydraulic lift table using a 1/2” plate and a mag drill with 5/8” annular cutter. Then I used 1” threaded rod and tapped the center of the rod for all of my bolts to fasten the plate to the table. I adjusted each nut on the threaded rod until the fixture table was completely flat. It is a good table, the only downside to this is I don’t have any side walls to clamp to. But it suits us well for what we do.
That is a great looking table and design! A very clever method for leveling out the table surface. For me personally, I prefer a table without the side walls as I find they can get in the way when I want to use a regular C-clamp, Omega clamp, or Vice-grip clamp at the edge of the table. I think you could add side walls if you really want/need them. My Rhino Carts have small removable "side walls" for clamping parts vertically.

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Re: welding tabs tolerances

Post by adbuch »

By the way - Siegmund makes welding tables with metric holes/spacing. They are pricey - but good to be aware of.
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Re: welding tabs tolerances

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SRdesign wrote: Sat Sep 17, 2022 8:40 am I have wanted to build a table at home for a while. I built a 4’x6’ table at work
I really like the idea of adjustable height with the lift table.
Personally I do like a bit of adjustability and even worked at a company where I had an hydraulic lift table in my part of the workfloor but totaly forgot about that.
adbuch wrote: Sun Sep 18, 2022 1:31 am
Just curious - what is 3500K euro? Is that different than 3500 euro or about the same as $3500 US?
With the current exchange rate it's pretty much the same, comes in at 3506 dollar.
So yes it's pretty steep for starting out hence the DIY approach coming in at about 300 dollar for material and about a day of work.
adbuch wrote: Sun Sep 18, 2022 1:57 am By the way - Siegmund makes welding tables with metric holes/spacing. They are pricey - but good to be aware of.
Found a supplier for those thanks to your tip.
Comes in at 1300 euros for a 1000x500mm table with adjustable legs excluding shipping.
Still need the tooling so that's also around 1500 euros or I need to diy those.
It's still alot cheaper then the other tables I found so I did make a note of those in my investment plan :Like
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Re: welding tabs tolerances

Post by adbuch »

I would be interested to see the plan for the table you are designing that you showed at your original post above - if you care to show it. Fusion 360 file would be fine. Thanks,
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Re: welding tabs tolerances

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adbuch wrote: Sun Sep 18, 2022 4:40 am I would be interested to see the plan for the table you are designing that you showed at your original post above - if you care to show it.
still working on it and before i release any files i do want to build it to make sure it fits together.
here are some quick renders, its 500x1000mm (19.6"x39.3") and 900mm (35.4') from ground to top with a 50mm hole spacing, i am a pretty tall guy and hate low tables :HaHa
500x1000 tafel.png
this is the internal part, probably going to add a 3rd short rib (the yellow one) in the centre.
500x1000 tafelinternal.png
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Re: welding tabs tolerances

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adbuch wrote: Sun Sep 18, 2022 1:46 am
SRdesign wrote: Sat Sep 17, 2022 8:40 am I have wanted to build a table at home for a while. I built a 4’x6’ table at work on top of a hydraulic lift table using a 1/2” plate and a mag drill with 5/8” annular cutter. Then I used 1” threaded rod and tapped the center of the rod for all of my bolts to fasten the plate to the table. I adjusted each nut on the threaded rod until the fixture table was completely flat. It is a good table, the only downside to this is I don’t have any side walls to clamp to. But it suits us well for what we do.
That is a great looking table and design! A very clever method for leveling out the table surface. For me personally, I prefer a table without the side walls as I find they can get in the way when I want to use a regular C-clamp, Omega clamp, or Vice-grip clamp at the edge of the table. I think you could add side walls if you really want/need them. My Rhino Carts have small removable "side walls" for clamping parts vertically.

David

buildpro 1.jpg

builpro 2.jpg
Thanks adbuch, that’s a great idea. I like the idea of removable side pieces so I can use them when needed. The leveling idea is not my own. I got the original concept from fireball tools. He used to sell adjustable studs that were tapped at a very low price per stud. I had planned on using them for this table but he took them down from his website before I could get started on this build, so I had to improvise. I just wanted to share another method to build a table, and yes the adjustable height is awesome. I purchased a file for a weld together fixture table a few months ago to make at home but I haven’t gone through with cutting up the plate yet.
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Re: welding tabs tolerances

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Never mind. Here they are. https://fireballtool.com/products/plate ... ner-1-stud
But they are sold out and I think they’ve been sold out for a while.
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Re: welding tabs tolerances

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SRdesign wrote: Sun Sep 18, 2022 8:02 am
The leveling idea is not my own. I got the original concept from fireball tools. He used to sell adjustable studs that were tapped at a very low price per stud.
We used the same concept when we built the 2M prototype mirror for the Next Generation Space Telescope back in the day. We had motor driven actuators attached to the back of the mirror to make adjustments under computer control to adjust the mirror to keep it in focus with temperature changes. There actuators would either push or pull to distort the mirror as needed for best focus. I expect they implemented something similar on the actual telescope. The work I was involved with as a Mechanical & Electrical Engineer was at the University of Arizona, Space Sciences, Lunar & Planetary Lab in conjunction with Optical Sciences and Steward Observatory. Jim Burge was the PI in the project.

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Re: welding tabs tolerances

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Plasma-art wrote: Sun Sep 18, 2022 5:25 am
adbuch wrote: Sun Sep 18, 2022 4:40 am I would be interested to see the plan for the table you are designing that you showed at your original post above - if you care to show it.
still working on it and before i release any files i do want to build it to make sure it fits together.
here are some quick renders, its 500x1000mm (19.6"x39.3") and 900mm (35.4') from ground to top with a 50mm hole spacing, i am a pretty tall guy and hate low tables :HaHa

500x1000 tafel.png
500x1000 tafel.jpg
500x1000 tafel.jpg (18.12 KiB) Viewed 1471 times
this is the internal part, probably going to add a 3rd short rib (the yellow one) in the centre.

500x1000 tafelinternal.png
500x1000 tafelinternal 1.jpg
This looks great! Lots of fun to be had playing around with Fusion 360 for these sorts of projects. Please keep us updated as to your progress.
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Re: welding tabs tolerances

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adbuch wrote: Sun Sep 18, 2022 10:25 am This looks great!
thanks, i feel its a good learning experience taking the time and effort to draw stuff up.
spent another hour or 2 on it today drawing up some more accessories.
the more accessories i put onto it the more i think i need a bigger table :Wow

also to give credit where credit is due, i used this vise model for the render https://grabcad.com/library/bench-vise-27
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Re: welding tabs tolerances

Post by adbuch »

You most likely won't have all of your fixturing up on the table top at the same time, so your size may be fine for your application. My Rhino carts have storage shelves and brackets underneath the table for handy fixture and clamp storage.
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Re: welding tabs tolerances

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adbuch wrote: Mon Sep 19, 2022 12:40 am You most likely won't have all of your fixturing up on the table top at the same time, so your size may be fine for your application.
quickly made a model of one of the bigger frames i make to check the sizing and its more then big enough.
i did get a quick quote for laser cutting it and its not to expensive so that might be an option.
getting it laser cut does save me a bunch of work handeling the steel.
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Re: welding tabs tolerances

Post by adbuch »

I forget what the actual size of your table is, plus those mm dimensions confuse me. But it looks like you have plenty of room for your projects at that size. Nice work on the model.
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Re: welding tabs tolerances

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adbuch wrote: Tue Sep 20, 2022 11:21 am mm dimensions confuse me.
They do make more sense then imperial.
Took me an hour to figure out I needed a 1/4 key for a pulley the other day :HaHa
Only when I hit the fractional button on the digital calipers by accident and it switched from mm I figured it out.

But the table should be 19.6 by 39.3 in freedom units.
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Re: welding tabs tolerances

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Plasma-art wrote: Tue Sep 20, 2022 11:36 am
adbuch wrote: Tue Sep 20, 2022 11:21 am mm dimensions confuse me.
They do make more sense then imperial.
Took me an hour to figure out I needed a 1/4 key for a pulley the other day :HaHa
Only when I hit the fractional button on the digital calipers by accident and it switched from mm I figured it out.

But the table should be 19.6 by 39.3 in freedom units.
It's whatever one is used to. I typically work in inch decimal units. So 1/4" = 0.250" and so on.
For mm, I always have to divide by 25.4 to get inches. If someone tells me a size is 1000mm - I really have no idea how big that is. In my head I can divide 1000 by 25 to get 40 inches which is in the ball park. If you grew up using metric, then inches may seem foreign to you.
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