Rotary Table Choice 36:1 o 90:1

Peter

Another suggestion for your every growing project list would be a grid of tapped holes plate to sit on top of the standard table. With smaller tables conventional Tee nut, stud, step block and clamp bar systems take up disproportionate amounts of space and are frequently too cumbersome for Model Engineer size jobs. With only 4 slots direct bolting can be difficult too.

Something like the ThorLabs 1/2 " thick range with M6 tapped holes on 25 mm centres would work well. The MB1515/M 150 mm square version is almost affordable at £39 (+VAT & delivery) **LINK** instead of rolling your own. The double density hole pattern 150 mm diameter MBR150/M is probably the one to copy **LINK** as £98 (+VAT & delivery) is just too spendy.

Aluminium tooling plate is the material to use as its already decently flat, machines well and is reasoanbly ding resistant.

For smaller jobs with smaller cutters quite lightweight clamps can be fine.Having fitted my old BCA with an "obtained" Thor Labs table I made a bunch of hold downs out of 1/4" or 3/8" thick material with M6 or 1/4" jacking screws built in. These were generally satisfactory, especially if I could arrange a direct bolt or two through the job. I tended to use more clamps than strictly needful and temporarily remove any that were in the way of the cutter.

I also made a number of very simple 1/8" or 3/16" thick bent sheet L shape ones inspired by the predecessors to the Thor Labs CL5, 6 & 8 ranges **LINK** . Usually with a couple or three holes rather than slots. Easier. Being a quick'n dirty bend job I shed no tears if the best way to deal with a cut involved chomping into a clamp rather than shuffling stuff around.

I found jack screws working from underneath like the CL8 and CL3 something of a pain in use. Generally having the screw out of the top so the jack height could be set during installation worked better but sometimes underneath was the only way. If you do use jack screws a protector plate under the end to avoid chewing up the table is essentail. I went swanky with free running pressure pads, G-clamp style, lots of extra work for pose points.

Many folk manage just fine with the standard Tee slots. All depends on the job and your work-holding creativity threshold. Two out of the first three jobs on my BCA were a right pain with the standard 3 tee slots so something more in tune with my (then) needs had to happen.

Clive

Not sure I want to tackle that on my SX1LP !!

Grid of holes boards and clamps are fair bit of work but worth the effort if its better / easier for your sort of work than the standard slots and normal clamp systems.

Sort of thing I tend to have sketched out ready to do if a suitable piece of material turns up and an appropriate job arrives.

You don't have to fit all the holes at once.

What primed me for the idea was a couple of hard to hold in the vice jobs where I just shoved a few tapped holes in a bit of scrap and got all crude with bolts, washers and strips with holes. So when the real thing appeared I knew I could use it.

As always its finding the best solution for your work and equipment. Knowing what has been successfully used by others in the past is great for inspiration.

Clive

Thanks Clive - more additions to the list of projects!