5 ms·

What is a reasonable guess here..hmmm. I have no idea about how much these motors would cost but I am assuming given the number of office chairs (which move up

What is a reasonable guess here..hmmm. I have no idea about how much these motors would cost but I am assuming given the number of office chairs (which move up and down with a lever) we produce, they shouldn't be costing a lot. We get good office chairs which support up to 300 lbs for under $100. I am assuming the technology for moving tables should be similarly priced. A sturdy steel frame + planks (wood/composite) + up/down motor/hydraulic lift shouldn't cost more than $300 in my subjective opinion. I am not willing to pay more than that. Wonder how much would IKEA charge for these, if they made one (edited for typos).

jlgreco 13y ago
One problem I see with the chair-piston approach is that if you don't get each leg moving up or down at the same rate then you might get a jam. This could probably be overcome if it is indeed an issue at all, but probably worth considering.
- simplekoala 13y ago
  I have a simple(minded) idea here. Connect a damn horizontal rod between the two pistons/moving-legs on each side
  - nknighthb 13y ago
    Which will cause the desk to jam at a (potentially disastrous) angle when the motors get out of sync. Are you a programmer? Do you like it when a non-programmer tells you "just do X", because it must obviously be so simple? Why, then, are you so sure that you can come up with a better design than mechanical engineers without even studying the problem?
    - simplekoala 13y ago
      Apologies for shooting from the hip. Never meant to say I can come up with a better design than mechanical engineers. You seem to suggest that building this table requires some serious engineering chops. May be there is some truth to it. As a layman ( in mechanical engineering ) I find it extremely hard to believe that technology for synchronized hydraulic lifts is not commoditized yet. It just feels like these ergonomic goods producing companies are selling chairs/tables with super high markups ($900-$1500) for ergo chairs - really?). Seems like you have a better handle on the production costs of a hight-adjustable table. How much does it really cost?
      - nicholassmith 13y ago
        They probably make about 20-30% profit on each one dependent on the company. Making shit is expensive unless you're doing it at scale, the majority of people don't care about adjustable desks so the marketshare is by nature a niche. You then have staffing costs, design costs, distribution costs.
      - kyzyl 13y ago
        FWIW, we certainly can make synchronized tandem lifts, but as always it comes down to costs. Basically if you want both actuators to move in unison, you either need to directly link them mechanically, which is expensive to build/repair, and not very feasible over large distances, or you need to connect them electrically via their control signals. In the latter case, you would usually synchronize their controller clocks, and specify the motors/cylinders/whatever to both have a very tight positioning tolerance. Then you mount the surface being moved on a system of bearings that have enough freedom s.t. it will self center automatically, absorbing the tiny bit of misalignment that can (and WILL) occur. However, in my experience it's almost always better to use two passive, i.e. non-lifting, supports along with one actuator in the middle that is twice as powerful. In heavy lift applications it often comes down to getting a single cylinder that is powerful enough without blowing the cost through the roof. Nevertheless, if you look at marine architecture, airport gangways, earth moving machinery etc. you will often see just a single lifting point. And in three paragraphs we've gone from office chair pistons to front-end loaders! Yay HN! As I said... for what it's worth ;-)
    - tomrod 13y ago
      Why not use a crank then?
  - jlgreco 13y ago
    I think if you want to do it cheap, then a handcrank, 4 rubber belt drives, and 4 screw legs would be the way to go. The problem would be making it look acceptable (either hide the mechanism, or display it prominently and make it look nice.
  - DigitalJack 13y ago
    package that with a corded drill and you are good to go.
ygra 13y ago
They do make one. They charge 600 €.
nknighthb 13y ago
The >300lbs on a GeekDesk Max isn't how much it can support, it's how much it can lift. Your office chair can't lift 300lbs. It can't lift much at all. I also don't believe in the ability of a pair of $300 hydraulic lifts to consistently reproduce my presets. As someone who weighs close to 300lbs, I can also tell you you won't find a good office chair rated for 300lbs for under $100. Go look at the specs on office chairs closely. Most of them will be rated for less than 250lbs with no more than a few hours/day of use. If you want your own crappy top (planks? really?), the actual cost of a GeekDesk Max is $725-745. The non-max (275lbs lifting capacity) is $525-549. You want a vastly inferior product to save $225?
- minor_nitwit 13y ago
  Why does a desk need to lift 300 lbs? Seems like a ridiculous requirement.
  - nknighthb 13y ago
    50lbs desk surface, 3x ~15lbs LCDs, 5.6lbs laptop, ~15lbs desktop, other electronics, lamps, some books, papers, stands, containers with misc parts and things, whatever else I might be working on. It's a 6.5' x 2.6' foot surface, it holds a lot more than a laptop.
  - michaelbuddy 13y ago
    I got a geek desk, the original. Put my own top of plywood on it finished. I've got 3 24" flatscreens and abunch of other crap. I'm still not even near the lifting capacity. But I think of the higher end desk as a good idea for a quieter motor, not so much the need for more weight. With that said, I think a hand crank desk should be fine for most of us. If only I could find one that's reasonably cheaper. The hand crank desks I've seen basically cost the same as the geekdesk though, which I don't understand at all.
  - BrandonMarc 13y ago
    Perhaps because you weigh 160 lbs and your spouse / sexetary weighs 140 lbs?
encoderer 13y ago
Hydraulic lifts on chairs work because you can stand up to raise the chair! It doesn't have to lift hardly any weight.
- jamwt 13y ago
  A bit pedantic, but I think you mean "pneumatic lifts". Unless you have something very exotic, there's no fluid in your chair!

jlgreco 13y ago

One problem I see with the chair-piston approach is that if you don't get each leg moving up or down at the same rate then you might get a jam. This could probably be overcome if it is indeed an issue at all, but probably worth considering.

simplekoala 13y ago
I have a simple(minded) idea here. Connect a damn horizontal rod between the two pistons/moving-legs on each side
- nknighthb 13y ago
  Which will cause the desk to jam at a (potentially disastrous) angle when the motors get out of sync. Are you a programmer? Do you like it when a non-programmer tells you "just do X", because it must obviously be so simple? Why, then, are you so sure that you can come up with a better design than mechanical engineers without even studying the problem?
  - simplekoala 13y ago
    Apologies for shooting from the hip. Never meant to say I can come up with a better design than mechanical engineers. You seem to suggest that building this table requires some serious engineering chops. May be there is some truth to it. As a layman ( in mechanical engineering ) I find it extremely hard to believe that technology for synchronized hydraulic lifts is not commoditized yet. It just feels like these ergonomic goods producing companies are selling chairs/tables with super high markups ($900-$1500) for ergo chairs - really?). Seems like you have a better handle on the production costs of a hight-adjustable table. How much does it really cost?
    - nicholassmith 13y ago
      They probably make about 20-30% profit on each one dependent on the company. Making shit is expensive unless you're doing it at scale, the majority of people don't care about adjustable desks so the marketshare is by nature a niche. You then have staffing costs, design costs, distribution costs.
    - kyzyl 13y ago
      FWIW, we certainly can make synchronized tandem lifts, but as always it comes down to costs. Basically if you want both actuators to move in unison, you either need to directly link them mechanically, which is expensive to build/repair, and not very feasible over large distances, or you need to connect them electrically via their control signals. In the latter case, you would usually synchronize their controller clocks, and specify the motors/cylinders/whatever to both have a very tight positioning tolerance. Then you mount the surface being moved on a system of bearings that have enough freedom s.t. it will self center automatically, absorbing the tiny bit of misalignment that can (and WILL) occur. However, in my experience it's almost always better to use two passive, i.e. non-lifting, supports along with one actuator in the middle that is twice as powerful. In heavy lift applications it often comes down to getting a single cylinder that is powerful enough without blowing the cost through the roof. Nevertheless, if you look at marine architecture, airport gangways, earth moving machinery etc. you will often see just a single lifting point. And in three paragraphs we've gone from office chair pistons to front-end loaders! Yay HN! As I said... for what it's worth ;-)
  - tomrod 13y ago
    Why not use a crank then?
- jlgreco 13y ago
  I think if you want to do it cheap, then a handcrank, 4 rubber belt drives, and 4 screw legs would be the way to go. The problem would be making it look acceptable (either hide the mechanism, or display it prominently and make it look nice.
- DigitalJack 13y ago
  package that with a corded drill and you are good to go.

ygra 13y ago

They do make one. They charge 600 €.

nknighthb 13y ago

The >300lbs on a GeekDesk Max isn't how much it can support, it's how much it can lift. Your office chair can't lift 300lbs. It can't lift much at all. I also don't believe in the ability of a pair of $300 hydraulic lifts to consistently reproduce my presets. As someone who weighs close to 300lbs, I can also tell you you won't find a good office chair rated for 300lbs for under $100. Go look at the specs on office chairs closely. Most of them will be rated for less than 250lbs with no more than a few hours/day of use. If you want your own crappy top (planks? really?), the actual cost of a GeekDesk Max is $725-745. The non-max (275lbs lifting capacity) is $525-549. You want a vastly inferior product to save $225?

minor_nitwit 13y ago
Why does a desk need to lift 300 lbs? Seems like a ridiculous requirement.
- nknighthb 13y ago
  50lbs desk surface, 3x ~15lbs LCDs, 5.6lbs laptop, ~15lbs desktop, other electronics, lamps, some books, papers, stands, containers with misc parts and things, whatever else I might be working on. It's a 6.5' x 2.6' foot surface, it holds a lot more than a laptop.
- michaelbuddy 13y ago
  I got a geek desk, the original. Put my own top of plywood on it finished. I've got 3 24" flatscreens and abunch of other crap. I'm still not even near the lifting capacity. But I think of the higher end desk as a good idea for a quieter motor, not so much the need for more weight. With that said, I think a hand crank desk should be fine for most of us. If only I could find one that's reasonably cheaper. The hand crank desks I've seen basically cost the same as the geekdesk though, which I don't understand at all.
- BrandonMarc 13y ago
  Perhaps because you weigh 160 lbs and your spouse / sexetary weighs 140 lbs?

encoderer 13y ago

Hydraulic lifts on chairs work because you can stand up to raise the chair! It doesn't have to lift hardly any weight.

jamwt 13y ago
A bit pedantic, but I think you mean "pneumatic lifts". Unless you have something very exotic, there's no fluid in your chair!