Outer Limits 4x4 Board

built a fab table a few months back. decided I want to have a steel top to jig on as the form ply is about 4mm out of flat. also like the earth the table idea.

got a quote 6mm (1200x1600) $280, 8mm $350.

looking at ordering 8mm. but thinking 10 might be better?

Has anyone else done this? Is it flat enough or am I pissing in the wind.

Don't want to spend the money and have it bow either.

wish I could justify / afford a bluco table or similar, saw them at the show last year.

I've got a 10mm thick table at work and an 8mm one at home, the 10mm one is better but the 8mm is fine for what I do.
Be aware you're very unlikely to get a perfectly flat sheet so build your table frame with crosspieces and even shim the plate between the crosspieces and the underside of the plate to get it as flat as you can.
It's a good idea to have the plate larger than the frame size by around 50mm all around the table it makes clamping things down easier as you don't have to get clamps over the frame as well.
I've got my table on 4 lockable swivel castors so it's easy to move around as well.
I use lots of vice grip clamps, G clamps and F clamps for my fab work and I don't buy junk clamps only use the better brands. For G clamps I like T&E brand very heavy duty much stronger than Record, Bessey and all the others.
Regards Andrew.

mate, once again a perfect answer.

I will see how it fits on top of the form ply, if that fails I will take the ply off and shim it as you have suggested.

Was thinking of using laminex / chipboard underneath as thats about as flat as it gets.

Regards

Justin

everything awill said. but my table top is 12mm

One place I worked had a nice 65mm table top, farken heavy but good to work on.

Yer i also work at a place the have a table abou 4m x 3m and about 25mm thick. It had a Good frame under it with multiple legs, Then to get it flat we would level it wit a dumpy and packers.Down side was you needed an overhead crane to move the thing..

Thats huge. I made mine 1200 x 1600 so I could work around the whole table. I figured the longest thing i will be building is a 1600mm long trailing arm.

wish I could afford 25mm, would be so quiet to work on

bru21 wrote:Thats huge. I made mine 1200 x 1600 so I could work around the whole table. I figured the longest thing i will be building is a 1600mm long trailing arm.

wish I could afford 25mm, would be so quiet to work on

It's a duller thunk on a 25mm + table. But 8mm would suffice and 12mm will be pretty darn good.

Cheers

I've got a 20mm Bis top on my bench. Best bench I've used yet. My work uses 10mm steel tops and they are ample for most duties. All the boilys have 25mm bis tops, and they have plenty of dings!

Mining $hit is heavy

I have a frame table 3000mm long X 1500mm with 6mm plate on top. Its definetly not thick enough go the thickest you can afford is my opinion.

bru21 wrote:Thats huge. I made mine 1200 x 1600 so I could work around the whole table. I figured the longest thing i will be building is a 1600mm long trailing arm.

wish I could afford 25mm, would be so quiet to work on

Yer it was used to build vehicle turn tables on then they would be dismantled and bolted back together on site.

Ok so, to day I went to buy 10mm 1200x1600 for $407 ex.

I was half way there and realized the buggy will be wider than my table.

So I lashed out on a bit of 1600x1500x20mm.

I decided i will have this for ever and will do it right the first time.

I am going to hire a Magnetic drill and drill it every 100mm and tap it out to M12. That way I can use cyclone rod (I have 400+offcuts) and bolt everything down. I have drawn up a few angle brackets and rhs brackets that will fit either 90 or 45 to the table for jigging. I will make everything fit the holes Ie: notchmaster, vice etc so I can move them where it suits.

I'll put a pic up here next week.

New question Is how do I tap 200 odd holes dead straight.
Hoping to use starter tap, heaps of lube and either mag drill or reduction drill? Might have to buy a few start and intermediate ones as I can't see even a name brand thredding this plate. I was told Its higher tensile then mild too.

Thanks bru

cheers bru

Get it laser cut?

how are you moving the plate? It must weigh a lot!

not sure if laser can cut 10mm holes in 20mm plate. would be sweet to get it laser etched for hole position though.

as for moving it its 377kg so use our fork

Is there any particular disadvantage in just drilling the holes n not having them threaded. A bolt/threaded rod through the hole with a nut on top of the job and one under the table... tho I do realize you'll have to reach under the table to put the bottom nut on... Try it without thread first and if it's too much of a pita then tap 'em..

Water jet definitely will cut 20mm.

We used to drill thousands of holes a time in 12mm plate on site and they were drilled and tapped M.12.

We discovered that the best items to use were,

Proper CNC style centre drills to spot every hole after marking and
c/punching, (these can be drilled in quite deep)

Cobalt drill bits to then drill clean through the plate in one hit,

Plenty of soluble oil in a squirt bottle when drilling,

A good mag base drill,

A reversing tapping head for the mag base drill,

12mm intermediate taps with trefolex. (not sure how these will go in 20mm)

The center drill and cobalt bits can be had from any decent industrial supplier.

After drilling the holes use a countersink tool to clean them up prior to tapping.

Cheers

my workbench is 20mm plate.

it is steel frame beneath, very heavy, with huge castors
timber bearers for the 20mm timber base, then 20mm plate above that.
i love it and i can move it around the shed

Jes

drilling and tapping the welding bench is not the best idea, it will fill full of spatter and shit. I used to work on big machine centres and we used tapped bed plates about 50mm thick, took hours to clean when changing set up's.

If anything just drill it, easiest way would be on a machine centre, drill and tap also if its a must.

I drilled and tapped 16mm holes every 50mm on our tombstones, bars and bed plates, very long process and it was all cnc tapped.

thought about leaving grub screws in the holes. In reality I only tig things I like lately (and the buggy is 4130 and has to be tigged) so there is no spatter, and I can blow the grinding dust out.

found some sweet magnetic clamps at hare and forbes, might be more practical than holes.

got an estimate for nc hole drilling today - about 1 - 1.5k, no cnc machine on the coast is big enough.

cheers bru

find a plasma they will cut 20 mm then drill out the hole to suit the tap and use the magnetic drill to tap the holes or simplt drill/plasma the holes big enough and weld in threaded bungs/plugs or nuts heaps easier/cheaper .