Recommendation for a light, low geared, macro slider?

Hi,

I'd like to ask forum members for advice on a macro slider please. I have a two axis macro slider that's commonly available all over the internet under a dozen different names and no name. It uses a rack and pinion gear to drive the movement. It works but it's not ideal.

There are two problems, both of which come from the gear ratio. The first is that the gear ratio is too high. One turn of the knob moves the camera about 30mm. This makes it hard to make very fine even adjustments of the type needed for stacking at say 1:1 to 1:2. The second is that when pointed up or down, gravity will move the carriage, camera and lens downhill. Yes there's a lock knob, but that then requires two adjustments per shift, more time, and more chance of upsetting bugs.

Can anyone recommend a slider with a very low gear ratio? Single axis is fine. It might use a worm drive or have an additional gear train to reduce the ratio. It must be field portable and preferably light. So not a powered one.

Many thanks,

Rod

Rod McD wrote:

Hi,

I'd like to ask forum members for advice on a macro slider please. I have a two axis macro slider that's commonly available all over the internet under a dozen different names and no name. It uses a rack and pinion gear to drive the movement. It works but it's not ideal.

There are two problems, both of which come from the gear ratio. The first is that the gear ratio is too high. One turn of the knob moves the camera about 30mm. This makes it hard to make very fine even adjustments of the type needed for stacking at say 1:1 to 1:2. The second is that when pointed up or down, gravity will move the carriage, camera and lens downhill. Yes there's a lock knob, but that then requires two adjustments per shift, more time, and more chance of upsetting bugs.

Can anyone recommend a slider with a very low gear ratio? Single axis is fine. It might use a worm drive or have an additional gear train to reduce the ratio. It must be field portable and preferably light. So not a powered one.

Many thanks,

Rod

I have a couple of NiSi NM-180 rails and a Haoge FM-160.

They are comparable in weight and size, with the NiSi being slightly larger because of the greater length and the rotatable clamp.

The NiSi is sort of the darling of the macro world right now. It has a fairly fine lead screw (what you called a "worm drive") that moves a highly controllable 1.25mm/turn. It's a pain to move a large distance, though. They give you a flip-out crank handle on one knob so you can haul it back quickly. It has a rotatable Arca clamp to accommodate lenses with long standard plates like my 200mm f/4 Micro-Nikkor. For me, the rotatable clamp is a necessity for any main (single rail or top rail in a stack) use. It goes for around $130.

The Haoge has a large, steep pitch lead screw" and can smoothly move 4mm per turn, making it a very controllable alternative to a typical 15-25mm/turn rack and pinion. It has a fixed 90-degree Arca clamp, meaning you need to use it with a Hel-L bracket on your camera or a square "bidirectional" Arca plate on camera or lens. If your lens has a long standard Arca plate you're kinda SOL). It's a great lower (cross) rail and it's even useful as a vertical "lift" rail. It goes for around $70 or near half what you pay for the NiSi.

I prefer the "quicker" 4mm/turn at 1:1, the fine 1.25mm/turn is more a 5x sort of thing.

Hi 3D and Joseph,

Thank you for your suggestions - plenty of scope there.

Cheers, Rod

3D Gunner wrote:

I have built a large and heavy device that contains three fast focusing rails, two for front and back advance and one for side shift, plus another fine lead screw system.

Sounds fascinating. Would you care to share what you built it for, and perhaps share pics of the rig and the results?

The camera plus the macro accessories are mounted on a two point sustaining system, and the two rails for the front and back advance is to additionally provide a weight balance to the whole toy (close to 3kg without the tripod, camera, lens and other accessories).

I had considered a moving counterweight system for my big rig. I'm already at 7 stepper motors: what's a couple more.

The portability is very discutable, but is fun to play with the whole toy.

Sounds like.

Details, please.

Rod McD wrote:

Hi 3D and Joseph,

Thank you for your suggestions - plenty of scope there.

You're welcome, Rod. Knowledge is to be shared, not hoarded.

Cheers, Rod

And you.

3D Gunner wrote:

Joseph S Wisniewski wrote:

3D Gunner wrote:

I have built a large and heavy device that contains three fast focusing rails, two for front and back advance and one for side shift, plus another fine lead screw system.

Sounds fascinating. Would you care to share what you built it for, and perhaps share pics of the rig and the results?

Details, please.

Pictured is the setup for using microscope objectives.

That is interesting. I don't think I've seen so many native system tubes stacked before. I stack a lot of M42 tubes, but those things are 1.0mm thread and sturdy like gas pipes, and I have adapters to M42 for all my objectives (RMS, M25, M26, M27) the 50mm Photar (M40) and enlarger lenses (M39 forward and M40.5x0.5 reversed).

What is the rotator under the camera? Is there a swivel section in the tube near the camera that we can't see from this angle?

For combinations with large extension, the mount is slightly different.
I also use several kinds of tripods and tripod heads, plus a motorized attachment.

Doesn't everyone?

And I'm also designing a much lighter version with linear ball bearings.
For all macro shots I use this toy, or parts of it, plus/minus other accessories.

It's great fun out in the field, where you can lose an entire day for 1-2-3 or a few photos, where someone else is frying several varieties of meat, paired with cold beers.

Absolutely. The journey is sometimes more important than the destination.

The combination with this type of tripod head is very high; for a more stable balance and elimination of vibrations, a different, lower height tripod head is recommended!

Or a heavy gear head with thick castings. The old Manfrotto 405 kills vibrations, but the thing weighs, if memory serves, 2kg all by itself.

But for more control, I'm playing with a yoke design right now. Lowers the COG and reduces bounce from the lateral arm. The problem is that it means doubling at least the elevator lead screw rails (and syncing them with stepper motors) and either doubling the rear standard pitch geared rotators or having a geared rotator on one side and a plain swivel on the other.

This is an ancient version of the rear standard, with a Haoge 160mm rail for lateral, a NiSi 180mm rail on elevation, and a double L arrangement that bounces far too much to actually use for anything, even when it's all being run by steppers, hence the move to double elevators and a yoke or possibly square internal frame.

The front standard is less complicated, and when it's all together there's 7 steppers total running the thing.

The more complex the serial robot, the less stable. At the rate I'm going, I'll have gone to a parallel robot before I manage to get the serial version running properly. The Stewart drive version is 6 DoF, but much simpler, smaller, and stronger.