I was watching videos of fixture tables being built recently. I noticed that the fabricators made some design choices that will be an inconvenience later once they starts using the table. This gave me the idea to put together a short list of mistakes I’ve made that you should avoid if you decide to make your own welding table. Everyone is welcome to add to the list if you’ve tried something that didn’t work well as you thought.
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Don’t start with warped or bent piece of steel. I know this seems obvious but it’s very difficult to straighten a bent piece of heavy plate steel. Leaving it bent is also a bad idea. The bent plate will transfer into everything your trying to build with the finished fixture table. Keep the bent or warped plate for a workbench. This includes a existing table top that your thinking about converting into a fixture table. Your going to put a lot of time and money into the project and the overall condition of the surface can create a lot of problems down the road.
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Picking to thin of a table top. This is bad for several reasons. Thin plate is harder to keep flat. Thin plate is can bend with heavy objects or large clamping loads. Thin plate isn’t the best choice for trying to straighten metal with the table clamps. It’s more prone to bending and warping due to heat transfer. Table clamps and tooling doesn’t work as designed. 1/2 is a minimum thickness plate if you want to avoid problems.
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The frame of the table is in the wrong location. This comes into play when you start drilling the holes. I’ve seen tables where holes are skipped do to the frame underneath is blocking the hole. Flat bar on edge is a good material to use to avoid the hole layout.
- Wrong hole spacing. This is the most common mistake I see. The holes aren’t just for clamps they are for fixtures also. Clamps don’t care what the hole spacing is. They have a large range of distance that they can reach. More holes is preferred. It’s nice to have more options to get the clamp in a position that is out of the way for welding accessibility. Off the shelf fixtures are designed to be on a specific hole center. Fixtures are made in a way where 2 holes in the table are used at the same time. I see lots of DIY tables with 5/8 holes with a 3,4, and 6in hole centers. This is wrong. This distance is to far apart for any off the shelf tooling to work properly. I understand that you don’t want to drill all the holes on a 2in distance because it will take longer, but you won’t be able to use the manufactured tooling. 2 in hole centers was chosen to keep the fixtures as small as possible.
- Stay on grid! Don’t go crazy and make random holes in the surface. Random placed holes don’t work with off the shelf fixtures. It also makes creating a fixture map in CAD impossible. It also looks sloppy and disorganized. This includes the 5 hole pattern.
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Avoid threaded holes. They get plugged up with grinding dust and crud. They are slow to use compared to a through hole. Through holes are easier to clean and you can still bolt stuff to the table with them. A sub plate is a great idea if you need threaded holes on the surface for a project.
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Avoid tee slots. These can be difficult to add fixtures and clamps to the table because most tee nuts feed in from the side of the slot. Yes you can get fancy tee nuts that can be placed in from the top but most people don’t have these. Tee slots don’t offer the accurate fixture placement like the holes on a grid system does.
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Leg braces in the wrong location. If you want to sit at the table keep the leg braces out of the way of your shins and feet. Being able to use the foot pedal and getting comfortable is going to help make nicer welds.
