Granite Surface Plate

[Deanimator]

Are you going to mount both your subject stage and your camera / lens to the horizontal T-slot member? If so, then I'd personally recommend soft-mounting it. I like to use 3M wall-mounting double-stick tape for such purposes (the grey color, not the super-strong black). A few strips of it in strategic spots will hold it firm, and it will be relatively easy to move around. Best of all, no drilling! You can also tailor the resonance characteristics by putting on additional layers of the material. It has high dampening qualities so helps absorb higher frequency stuff coming from the table.

Edited to add: if the subject will mount to a different system which is mounted to the steel plate, then soft-mounting won't work well.

I haven't decided yet.

What I'd wanted to do was to use a combination of the 40mm x 40mm and 40mm x 120mm. Unfortunately, there's no linear bearing for the wide profile, making rough focus tough.

So I'm now looking at 40mm x 40mm for both vertical and horizontal. I don't think that would be stable with the vertical portion installed unless it was mechanically attached to the plate, or at least had transverse legs of some sort, a la Wemacro.

That also makes available space for horizontal shooting limited. I'd like to be able to shoot things bigger than pinned insects, so I'm probably going to have to rig up some kind of platform that will be attached to the horizontal profile.

[ray_parkhurst]

For a vertical post, I've had excellent performance from a long 1/4-20 threaded rod, with nuts and washers either end of the 4040 column. On the 4040's I have the hole in center is large enough to fit the 1/4 rod with just a little extra room...perfect. Just make sure the column is machined flat on the mating surface, and the plate is clean. Only requires one hole to drill.

PS it should work splendidly to drill and tap the steel plate for 1/4-20. Then install the rod and column and cap it off with washer and nut.

[Deanimator]

For a vertical post, I've had excellent performance from a long 1/4-20 threaded rod, with nuts and washers either end of the 4040 column. On the 4040's I have the hole in center is large enough to fit the 1/4 rod with just a little extra room...perfect. Just make sure the column is machined flat on the mating surface, and the plate is clean. Only requires one hole to drill.

PS it should work splendidly to drill and tap the steel plate for 1/4-20. Then install the rod and column and cap it off with washer and nut.

My original plan was to mount the 40mm x 40mm vertical to the 40mm x 120mm horizontal, which should have been stable. Now that the 120mm piece is off the table, so to speak, the vertical will have to be fixed to the plate, or to the horizontal, which would be fixed to the plate.

Would you drill completely through the plate to mount the vertical or drill and tap a blind hole? What you suggest is exactly what I have now, only substituting the aluminum profile for the wooden furniture leg and the steel plate for the wooden cutting board.

If I were to go that route, it might behoove me to literally duplicate my existing rig, including vertical profiles of different heights for horizontal use (and mounting the Wemacro directly to the table).

[ray_parkhurst]

For a vertical post, I've had excellent performance from a long 1/4-20 threaded rod, with nuts and washers either end of the 4040 column. On the 4040's I have the hole in center is large enough to fit the 1/4 rod with just a little extra room...perfect. Just make sure the column is machined flat on the mating surface, and the plate is clean. Only requires one hole to drill.

PS it should work splendidly to drill and tap the steel plate for 1/4-20. Then install the rod and column and cap it off with washer and nut.

My original plan was to mount the 40mm x 40mm vertical to the 40mm x 120mm horizontal, which should have been stable. Now that the 120mm piece is off the table, so to speak, the vertical will have to be fixed to the plate, or to the horizontal, which would be fixed to the plate.

Would you drill completely through the plate to mount the vertical or drill and tap a blind hole? What you suggest is exactly what I have now, only substituting the aluminum profile for the wooden furniture leg and the steel plate for the wooden cutting board.

If I were to go that route, it might behoove me to literally duplicate my existing rig, including vertical profiles of different heights for horizontal use (and mounting the Wemacro directly to the table).

Unless the plate is very thick, it's generally best to drill and tap through.

[Deanimator]

Unless the plate is very thick, it's generally best to drill and tap through.

Based on Chris's recommendation I'm going with 5/8".

[ray_parkhurst]

Unless the plate is very thick, it's generally best to drill and tap through.

Based on Chris's recommendation I'm going with 5/8".

That is pretty thick for steel. You might consider a blind tapped hole. You need ~1/4" of good threads to get a nice grip on the threaded rod.

[Deanimator]

Unless the plate is very thick, it's generally best to drill and tap through.

Based on Chris's recommendation I'm going with 5/8".

That is pretty thick for steel. You might consider a blind tapped hole. You need ~1/4" of good threads to get a nice grip on the threaded rod.

An alternative would be to drill an oversized hole and epoxy in a threaded insert or coupler nut.

[ray_parkhurst]

Unless the plate is very thick, it's generally best to drill and tap through.

Based on Chris's recommendation I'm going with 5/8".

That is pretty thick for steel. You might consider a blind tapped hole. You need ~1/4" of good threads to get a nice grip on the threaded rod.

An alternative would be to drill an oversized hole and epoxy in a threaded insert or coupler nut.

To ensure the column has a very tight coupling to the base, the threaded rod needs to be tightened very tight. Will an epoxied insert hold up?

Also, it's best to minimize the amount of metal removed. I like the tapping concept over the through hole because you can drill a smaller (pilot) hole. Next best would be a 1/4" through hole. Drilling an oversized hole and installing an insert means you must remove a lot more metal than is really needed.

Personally I'd leave the insert as a backup in case you need to fix a mistake...

[Deanimator]

To ensure the column has a very tight coupling to the base, the threaded rod needs to be tightened very tight. Will an epoxied insert hold up?

Also, it's best to minimize the amount of metal removed. I like the tapping concept over the through hole because you can drill a smaller (pilot) hole. Next best would be a 1/4" through hole. Drilling an oversized hole and installing an insert means you must remove a lot more metal than is really needed.

Personally I'd leave the insert as a backup in case you need to fix a mistake...

Would it be a good ideal to put an HDPE disk between the post and the plate to protect both, the way I put stacked wooden disks between my furniture leg and the cutting board on my current rig?

[ray_parkhurst]

To ensure the column has a very tight coupling to the base, the threaded rod needs to be tightened very tight. Will an epoxied insert hold up?

Also, it's best to minimize the amount of metal removed. I like the tapping concept over the through hole because you can drill a smaller (pilot) hole. Next best would be a 1/4" through hole. Drilling an oversized hole and installing an insert means you must remove a lot more metal than is really needed.

Personally I'd leave the insert as a backup in case you need to fix a mistake...

Would it be a good ideal to put an HDPE disk between the post and the plate to protect both, the way I put stacked wooden disks between my furniture leg and the cutting board on my current rig?

No, better to have direct metal to metal contact to make the two pieces of metal as intimate as possible so they move as one.

[Deanimator]

No, better to have direct metal to metal contact to make the two pieces of metal as intimate as possible so they move as one.

Having given some thought to your idea of mounting the vertical profile directly to the plate, I'm considering always having some sort of 40mm x 40mm vertical post mounted to the hole in the plate. To this, I would add, using a gusseted corner connector and a couple of corner plates, a horizontal 40mm x 40mm profile to mount the subject stage. I'd probably use one of the smaller, cheaper no break linear bearings with a platform bolted to it.

To start, I think I would get a 24" and a ~80mm vertical post. I was originally going to make the horizontal profile 24" long, but now I'm leaning toward 36". I've got 48" on the table top.

[ray_parkhurst]

No, better to have direct metal to metal contact to make the two pieces of metal as intimate as possible so they move as one.

Having given some thought to your idea of mounting the vertical profile directly to the plate, I'm considering always having some sort of 40mm x 40mm vertical post mounted to the hole in the plate. To this, I would add, using a gusseted corner connector and a couple of corner plates, a horizontal 40mm x 40mm profile to mount the subject stage. I'd probably use one of the smaller, cheaper no break linear bearings with a platform bolted to it.

To start, I think I would get a 24" and a ~80mm vertical post. I was originally going to make the horizontal profile 24" long, but now I'm leaning toward 36". I've got 48" on the table top.

The stand I built using a composite base has 24" vertical post, and it's not quite tall enough for the 3.5x lenses I'm working with. The 80cm vertical post sounds perfect, with enough height for most work we do, and yet a bit shorter than 36". This is important because most of the threaded rods come in 36" lengths, so being a bit shorter gives room to stick out the top.

[Deanimator]

The stand I built using a composite base has 24" vertical post, and it's not quite tall enough for the 3.5x lenses I'm working with. The 80cm vertical post sounds perfect, with enough height for most work we do, and yet a bit shorter than 36". This is important because most of the threaded rods come in 36" lengths, so being a bit shorter gives room to stick out the top.

Actually, I said 80MM, but an 800mm post for vertical wouldn't be bad. An 80mm and an 800mm would probably do well.

The 80mm would give me enough post on which to mount the horizontal profile and the 800mm would give me good vertical working distance.

[ray_parkhurst]

The stand I built using a composite base has 24" vertical post, and it's not quite tall enough for the 3.5x lenses I'm working with. The 80cm vertical post sounds perfect, with enough height for most work we do, and yet a bit shorter than 36". This is important because most of the threaded rods come in 36" lengths, so being a bit shorter gives room to stick out the top.

Actually, I said 80MM, but an 800mm post for vertical wouldn't be bad. An 80mm and an 800mm would probably do well.

The 80mm would give me enough post on which to mount the horizontal profile and the 800mm would give me good vertical working distance.

I just thought 80mm was a typo.

[Chris S.]

Responding to points from several posts: (I've also replied off-line to Deanimator.)

Strongly agree with Ray that in this situation, we want metal-to-metal contact for efficient mechanical coupling.

Drilling and tapping 5/8" steel is child's play for a fabricator like Don. I can even do it myself quite easily. Steel takes threads so nicely that epoxying in an insert would decrease, rather than increase, holding strength. Epoxying in an insert would also needlessly add complexity.

But for mounting vertical things on a steel base-plate, one should also consider through-bolting, using an unthreaded hole with countersinking on the underside of the base. In this way, a flat-head machine screw can be inserted from under the steel base. The head will be flush with the bottom of the base-plate, or better, slightly recessed into it. The threaded portion of the screw will extend through the base plate and above it, allowing whatever riser is used to be either screwed to it (if the riser has a threaded hole) or bolted using a nut. Through-bolting with steel is a very strong method of attachment. Again, a decent fabricator can do this easily. On my rig, the vertical post (labeled part M) is attached this way.

Also, we should keep in mind that a fabricator can also weld things to a steel base-plate. As an example, right-angle stock to which a rise could be bolted or braced. Not sure if this is useful for Deanimator, but it's worth remembering. On my rig, Don welded on handles--which makes the rig ever so much easier to move.

I'm having trouble envisioning exactly how Deanimator envisions this rig. A sketch would be helpful.

Cheers,

--Chris S.

PS--Rather distant from Deanimator's immediate needs, but worth mentioning: Heli-Coil® inserts. I can't recall ever stripping the threads from a hole in thick steel, but have done it in aluminum. An easy way to fix this was to place a Heli-Coil® insert in the aluminum, effectively giving it steel threads.