Synchronizing Pneumatic Telescopic Cylinders

Why wouldn't you have matching equalized cylinders? In any case a more detailed drawing of the assembly would be helpful...

The cylinders are the same.

Maybe on Monday when I get back to work I can post a better drawing.

thanks.

not a great photo

Pretty much my thoughts. I wanted an electric linear actuator with a servomotor but my boss and the customer thought a telescopic pneumatic cylinder would be better. One lever pull and task complete.

We get close but not sure it's repeatable.

Maybe this, similar to cross-compounding dc motors

https://www.youtube.com/watch?v=_KTv8K3TVcc

Not intuitive, but I think I've seen something like this before. Also saw this, I've not seen this in practice, but no design parameters, 3 equal volume cylinders, compensation for rod end volume, and stated for hydraulic, as mentioned by Tornado...

https://www.youtube.com/watch?v=YmmHCnP__gE

I'd worry about how well it works after 6 months of wear and condensate at customers poorly maintained air compressor dryer...

In the first link, the cylinders won't synchronize (mismatched cross-sectional areas).

I think the second link works in theory, but if there is any difference in CSAs, or even a slight leakage, it too will become out of sync.

The video does show that too, I never noticed!

And I’d wonder about the transition between stages, if off a little bit, would really jump out of synch fast.

I'm curious to know what their rationale was, if any.

A crosshatch assembly confined to tracks might work...

Unfortunately at this time I am trying to fit everything in a small space. Currently working on a more rigid linear bearing.

You could make a swivel attachment for the cylinders on a crossmember that attached to the drawer at the midpoint, which also swiveled...this would reduce stress on the linear bearings...

I will post some pictures on monday.

I have several links to look at on Monday.

I wonder if you could use a rodless cylinder to take part of the linear bearing function and still get the stroke that now requires telescopic cylinders?

https://www.hydraulicspneumatics.com/technologies/cylinders-actuators/article/21887509/less-is-more-considerations-for-choosing-rodless-pneumatic-cylinders

You need a rigid, guided connection between the two cylinders. The guide needs to be stiff enough to not twist and bind.

By the time you have that designed and integrated into your small space you will have spent the same time and money a servo actuator would have cost.

Agreed. Now to convince my boss. That meeting is planned for today.

https://cr4.globalspec.com/search/sitesearch?do=show&fs=14&srchobjs=t%2Cc&order=asc&query=Synchronizing+Pneumatic+Cylinders&sort=textmatchrank&mindate=-

You're right. I didn't do a search.

I did review the titles and none of them refer to telescopic cylinders.

There is a spendy way to synchronize 2 pneumatic cylinders, but that method won't work for telescopic cylinders.

The meter out flow controls were switched to meter in flow controls with more adjustment range. Now we are getting the synchronization needed to make it work.

Next step is getting rigid linear bearings. They are being ordered now.

something Rack and pinion - Wikipedia and/or Bevel gear - Wikipedia and/or Drive shaft - Wikipedia +maybe ?? Screw (simple machine) - Wikipedia ??