Welding fixture table types to fabricate

[Machinitect]

I’m getting ready to machine and build a welding fixture table with 5/8” holes and a 1” thick steel top, around 4x8. I’ve seen the type with slats and multiple plates, as well as the type with a single large work surface.

Other than making it easy to machine and drill each slat, is there a benefit to the slat type table over the large work surface type? I attached a photo of the one with multiple plates.

 

[GeoBruin]

Off the top of my head:

- In addition to using clamps that use the 5/8" holes, you can use a standard "F" style clamp because the clamps can stick down between the slats to clamp to the bottom of the table. This also applies to standard locking c-clamps and just about every other type of clamp.

- If you're working on a part or assembly that you want to clamp down, but it has a feature that sticks down below the plane of the table, you can remove 1 or more slats to make room.

- You can remove slats to access your assembly from underneath if you need to weld from the bottom.

- If you damage your table (gouging it with a grinder, welding to it, etc) you can replace a single damaged slat relatively economically.

- You can swap in different slats with different size/spacing fixture holes, or threaded holes, etc. for specific applications.

- You can make a set of slats that are full width with no gaps and no holes to use as an assembly bench where you don't want fasteners or small parts falling through the table.

 

[Machinitect]

GeoBruin, I appreciate your detailed reply. I’m liking the idea of slicing up my 1” sheets and going with the slat design.

Another positive is squaring the edges on the mill and drilling the hundreds of holes with auto down feed instead of my mag drill by hand. It seems like each slat would be difficult to align but maybe that is no big deal.

The extra set of zero gap/ zero holes solves the problems that I had in mind because I will also be using the table to rebuild engines and to repair stuff. Thank you!

 

[strength_and_power]

There is a plethora of fixture table options out there today. I don’t know what your time is worth but buying one ready to go might acabe cheaper by the time you figure in time spent cutting holes and getting the slats ground so you actually have a flat surface.
Twenty years ago, I built a table with slots to use F clamps and later drilled 5/8” holes for fixture clamps. I used 1/2” so there wasn’t enough meat to have it ground. It’s flat-ish. If I need another table, it will be bought.

 

[Machinitect]

There is a plethora of fixture table options out there today. I don’t know what your time is worth but buying one ready to go might acabe cheaper by the time you figure in time spent cutting holes and getting the slats ground so you actually have a flat surface.
Twenty years ago, I built a table with slots to use F clamps and later drilled 5/8” holes for fixture clamps. I used 1/2” so there wasn’t enough meat to have it ground. It’s flat-ish. If I need another table, it will be bought.

I hear you for sure. This is one of those cases where I got all excited and ordered the fireball template, several annular cutters, and several thousand $$$ in steel plate and bar stock. My time in the shop isn’t worth anything other than the fun factor. Can’t wait to have a proper welding table.

 

[BroncoAZ]

I have a certiflat table I found on Marketplace last year. It works fine for me, for non welding use I keep a piece of 1/4” hard board on the surface.

i thought the main idea behind the slot tables was to be able to adjust them to be perfectly flat across the surface using bolt tension. Using standard F clamps also makes sense. Swapping out the slats for a set without holes seems like it would be a major hassle to get everything perfectly level again. I agree with not wanting to hand position the mag drill for a flat table vs using the mill and having everything perfect.

 

[NUTTSGT]

I would suppose it depends on what you are doing for a majority of the time.

I never considered slats as I didn't wanted a split table and built mine with a used piece of steel for the top. While it's not perfectly flat, it's fine for me in my home shop.

I drilled all my holes and fabbed my clamps from store bought.

 

[GeoBruin]

down feed instead of my mag drill by hand. It seems like each slat would be difficult to align but maybe that is no big deal.

Machine yourself a jig. That way you just place the first slat, then use the jig to place the 2nd slat relative to the first and so on.

 

[Retired dozer fixer]

Ok I’m not a machinist but why would you spend thousands on a machined table top with fixture holes and **** it up by welding on it? Why wouldn’t a scrap metal top be good enough especially since you give the impression that you’re a hobby shop? I’m not poking at you just trying to understand spending thousands and lots of time for something that could be done for less

 

[Machinitect]

Ok I’m not a machinist but why would you spend thousands on a machined table top with fixture holes and **** it up by welding on it? Why wouldn’t a scrap metal top be good enough especially since you give the impression that you’re a hobby shop? I’m not poking at you just trying to understand spending thousands and lots of time for something that could be done for less

Yes, just a hobby and I’m ready to have a nice clamp table for better results. I will also build some items for my company once the shop is set up for it. Right now I mostly weld on a concrete floor.

I’d guess ordering and shipping a similar weight table would be around 12-15k and I can build it for around 3k with materials already purchased. Years ago I machined a home gym rack with over 800 holes drilled. That thing was fun to build, and it is still great to use.

I was really just asking whether there are benefits to slicing up my sheets instead of just building the large table, and I’m getting some great responses.

 

[strength_and_power]

When I added holes to my slotted table, I had a local shop laser me a template with 5/8” holes on 2” spacing on two sides. The rest of the template was 3/16” holes on 2” spacing. I put shoulder bolts in the 5/8” holes and used those as stops. Marked my 3/16” holes with a 3/16” punch then center punched the marks to make finding the mark easy with the guide pin on the annular cutter. Slid the mag drill all over the marked section popping holes then used the template and 5/8” shoulder bolts to advance my template and keep the spacing. It worked well and made a ton of swarf.

 

[Machinitect]

When I added holes to my slotted table, I had a local shop laser me a template with 5/8” holes on 2” spacing on two sides. The rest of the template was 3/16” holes on 2” spacing. I put shoulder bolts in the 5/8” holes and used those as stops. Marked my 3/16” holes with a 3/16” punch then center punched the marks to make finding the mark easy with the guide pin on the annular cutter. Slid the mag drill all over the marked section popping holes then used the template and 5/8” shoulder bolts to advance my template and keep the spacing. It worked well and made a ton of swarf.

Great solution. Now fireball makes that template for around $200, and I ordered it. I could have made it, but I like the idea of a drill jig with perfect holes and hardened inserts. After the table is done, the jig becomes a fence for welding. When I built the home gym, I ended up with a 50 gallon drum of stringy chips from that annular cutter drilling 800 holes. Wow.

 

[NUTTSGT]

For a home shop, do you really need a 4x8 table or will something smaller work ? A table that large, once in place will more than likely, stay in that same spot. My table is 48"x60'x1/2" and is on casters so I can move it around.

 

[Steve_P]

A 4'x8'X1" rolled steel plate might have a half inch, or more, bow in it. This is why people build tables out of bars. You can buy blanchard ground plate from Ryerson, or you could, but if you look up the tolerance specs for flatness on an as-rolled plate you'll be shocked.

 

[Machinitect]

For a home shop, do you really need a 4x8 table or will something smaller work ? A table that large, once in place will more than likely, stay in that same spot. My table is 48"x60'x1/2" and is on casters so I can move it around.

My last table that I sold was 4x12 and I usually worked in a little corner of it because an engine or transmission was scattered all over it. I do like the idea of several small tables like (4) 4x4 tables that could be bolted together or moved around. Appreciate your comment.

 

[Machinitect]

A 4'x8'X1" rolled steel plate might have a half inch, or more, bow in it. This is why people build tables out of bars. You can buy blanchard ground plate from Ryerson, or you could, but if you look up the tolerance specs for flatness on an as-rolled plate you'll be shocked.

I’ll have to measure my steel when it arrives. I’ve never seen a 1” thick piece of 4x8 new steel so that is some good insight of what to expect. I made a heavy vise stand a while back out of 2x2x1” thick mild steel and I really like working on it. The shop has a Cincinatti dial mill, so I guess the plate could be fly cut flat if it needs it. Looks like this will be a fun project.

 

[tarbellb]

Getting something truly flat is hard. There are a few ways to achieve +/- .005 flatness over 4x8

Most common is to have something Blanchard ground, but this is expensive and not always available locally

The other way is Slates- welding threaded standoffs to the underside and tweaking each plate the a workaround

Looks like you've already bought your materials so the option of tab n slot plates doesn't apply, but these are another method. Even then I had to shim my tab n slot table w .010" shims before welding to achieve +/-.005" flatness

Good luck w the table, how do you plan to cut the plate?

 

[Machinitect]

Getting something truly flat is hard. There are a few ways to achieve +/- .005 flatness over 4x8

Most common is to have something Blanchard ground, but this is expensive and not always available locally

The other way is Slates- welding threaded standoffs to the underside and tweaking each plate the a workaround

Looks like you've already bought your materials so the option of tab n slot plates doesn't apply, but these are another method. Even then I had to shim my tab n slot table w .010" shims before welding to achieve +/-.005" flatness

Good luck w the table, how do you plan to cut the plate?

If I end up cutting the plates, it will be with a milwaukee metal circular saw.

 

[tarbellb]

If I end up cutting the plates, it will be with a milwaukee metal circular saw.

Going to have a helluva day (week) cutting 1" w that saw

 

[Machinitect]

Going to have a helluva day (week) cutting 1" w that saw

Yeah, maybe this makes the decision for me to just leave the table large and one piece. Thanks for everyone’s comments. I think I have enough info to start drawing up a design and testing out some drilling when the material shows up.

 

[strength_and_power]

Great solution. Now fireball makes that template for around $200, and I ordered it. I could have made it, but I like the idea of a drill jig with perfect holes and hardened inserts. After the table is done, the jig becomes a fence for welding. When I built the home gym, I ended up with a 50 gallon drum of stringy chips from that annular cutter drilling 800 holes. Wow.

My first order from a high school for power racks was for 12 7’ tall racks with 1” and 2” holes spacing. I used a jig and a single rotonroach ultra cutter for all the holes. I was drilling for days.

 

[no704]

You can bolt 2 slats in one row and have a wider table.

 

[NUTTSGT]

My last table that I sold was 4x12 and I usually worked in a little corner of it because an engine or transmission was scattered all over it. I do like the idea of several small tables like (4) 4x4 tables that could be bolted together or moved around. Appreciate your comment.

If you're doing engine/trans work on it, I would consider a smaller table than a different workbench/table for the mechanical work. I added a torch table that slides out from under the steel plate top of my table.



PM sent.

 

[Steve_P]

I’ll have to measure my steel when it arrives. I’ve never seen a 1” thick piece of 4x8 new steel so that is some good insight of what to expect. I made a heavy vise stand a while back out of 2x2x1” thick mild steel and I really like working on it. The shop has a Cincinatti dial mill, so I guess the plate could be fly cut flat if it needs it. Looks like this will be a fun project.

I'm sure that the flatness tolerance that the steel plate producer gives is a worst-case so that 99.99% will be under the spec. I have a friend that did some consulting engineering work in a Caterpillar plant that made mining equipment, and they did not need flatness on a 4'x8' plate to be .12" but they still had a giant press that they almost always put plate stock into so that they could flatten it out to make it acceptable for making the giant **** that they do.

For you, if it's less than 1/4" bowed over 8', then that's a winner as far as that plate. Probably not good enough for your purpose, but....