Metal Expanding Table 01

[@margan59]

I'm so bummed that you haven't posted in 4 yrs. This is such a cool project. I would think someplace like Rockler might take it on. In any case, I hope your life is going well and your brilliant mechanical ability is being used.

[@olivier2553]

Scott, regarding the spring to take back the slag on the cable, you could use a compression spring. Terminate the cable with a threaded rod, throw this through a compression spring, a washer and a nut. The nut can adjust most of the slag, the spring is here only to take the last couple of millimeters. Compression springs can be much more compact and that one could be both shorter (it does not need to take a lot of slag) and stronger. On my motorbike, the rear brake is activated by a rod that attach to the break lever through a compression spring, each time you brake, you compress the spring, so it must be robust, and there is a nut at the end of the rod to take of the slag.

[@nielsencs]

Awesome project! As you were talking about welding to the hub at around 8:20 it struck me that bolting might have some advantages. 1. Less chance of distortion in the rim from the heat during welding. 2. Many folks don't have a welder (including me!) I don't know if you would be able to design this in such a way that even the welder would be unnecessary? If you could, the design would have even greater universal appeal :)

[@johnwurst6691]

Just found your videos. Very interesting, finally somebody that thinks a lot about things that could be. Keep it up!

[@peter-ip3uk]

A tension cable system which goes over centre can be kept tensioned if the other end mirrors the motion, but it then brings you back to the bent arm across the centre pivot to achieve it. Most closed loop aircraft systems do not have tensioning springs but rely on the cable stretch. The tension is moderately high and achieved by turn barrels. A little link off the cable to travel round the outer pulley is one way of reversing the direction.

[@s1ocky]

On the common thread of bike parts, some of the ‘exotic’ shift systems worn with dual cables to push/pull the gearing may be worth looking into. Examples include the pinion p1.12. Small cable readily available, designed to handle repeated flexing on a similar radius, along with housing that has braze-on attachments to simplify routing.

[@ScottRumschlag]

A transmission for my bike, complete with oil changes, ha ha. I'll check it out.

[@doseven]

For the springs on the last concept you could use pressurized gas struts. The type used on hatchback cars. The force is fairly linear over the range and they should be fairly ubiquitous throughout the world.

[@belg4mit]

Awesome, very excited to see a new capstan table.

[@baronvonlichtenbush8870]

Well done sir. I see some mentions of bicycle roller chain, which is a good idea in place of cable. Is it possible to attach the cable in your diagram in some sort of slot to act like a cam when the attachment point goes past the end of the track to allow for the direction change? Last thing that comes to mind is if you are still wanting to use a stationary plate in the center, is there enough room left on the spindle to thread another nut? If so possibly weld a nut to the plate and that would be a fairly easy way to get it stationary. Just some random thoughts.

[@oldporkchops]

Have you thought of using a half moon design for the extension slides? I can elaborate more if needed.

[@jrmitchellj]

Beautiful! I have been looking for this type of project! I know it has been two years since you published this, but have you considered using timing belt (like used in many 3d printers) instead of cable? Or maybe bicycle chain? I look forward to viewing the rest of the series. Ray

[@tochi_nozhi]

Good thoughts man! Looking to your new videos!

[@danielbostrom129]

Review how control cables in small aircraft are set up. Turnbuckles to adjust compression springs to maintain tension, etc. Cables, pulleys, turnbuckles, springs etc. all available at Aircraft Spruce and Specialties. They ship worldwide too. Check it out!

[@ScottRumschlag]

Thanks for the recommendation, new part sources are always welcome.

[@aserta]

Some ATV rims are perfect cylinders with a flat piece of metal welded inside for the attachment point.

[@ScottRumschlag]

So they are . . . that's interesting.

[@ImpGimp]

14:24 Why not try these sliders on an incline? The table rotates anyway.. so why not use that motion to have the table travel up. While they sit on the incline they are all in contact and thus ensuring a play-less movement. (though the range of motion might be too limited.. going 11" sideways has to transfer into the 2 units up)

[@PursuitofHappiness]

Good to see more videos! BTW, now I can’t NOT see the scare sign. Lol!

[@davidriley7659]

27:52 could always use a weight rather than a spring. If you had a pulley the weight could sit against the table leg. Not the most practical, but figured i'd point it out.

[@Daniel-ML]

Have you ever thought of using a car window track for the push / pull of the slides? Seems like it would work well and is ubiquitous.

[@ScottRumschlag]

I don't think it would be stiff enough.

[@WilliamWallace14051]

For the wrapped cable you could have the cable loop back to the hub a wrap in the opposite direction.

[@englishwords21]

Thumbs UP for international auditory !

[@reddcube]

Could you explain how you would attach the tension cable to the base. Is the fixed point brought up to the slider level. is the guide pulleys angled to allow horizontal movement at the slide, but a spiral to the fixed point Is the whole cable and pulley system angled like a wedge between the base and the outer point. The last would need some type of hinge between the cable's shuttle and the top slider. but depending on the geometry you could get the redirection movement with the hinge. the shuttle would never loop over the end pulley.

[@ScottRumschlag]

I think it will be clearer in the next video, when I begin testing the concept with actual hardware.

[@AvionsVoisin]

Why not use a chain between both sides of the cable. It can be wrapped around a cog, with the slide being moved by a shuttle attached to one or two of the chain link pins. i.e. both the cable/bowden tube and chain/sprocket can be made completely from common bicycle parts.

[@nraynaud]

For the rail, Igus N series rails could be interesting to evaluate (I think the keywords is "DryLin® N80" ). I don't know about the price, tho.

[@ScottRumschlag]

I've used other Igus stuff, it's nice but definitely costly.

[@TK-qm8rb]

Instead of springs... what about counter weights, like in the old double hung windows. The center of the table could house the weights.

[@Ravedave5]

Seems like a bicycle chain might be better than a cable. Also easy to convert to gears and cams.

[@ScottRumschlag]

I've thought a bit about chains, they have some major benefits but cables bend in two directions . . .

[@JeremyMcMahan]

Scott, Instead of a cable, how about bike chain?

[@plmi1]

I was also going to suggest the chain, but two people already commented.

[@WilliamWallace14051]

The are drawer slides meant to lay flat underneath drawers.

[@ScottRumschlag]

I've looked into those, too flexible.

[@TK-Thawngpi]

very good idea

[@clebiosilva4025]

Muito bom!!!

[@gandhizehner]

Hydraulics instead of cables!

[@ФёклаШиринкина]

Круть ,непонятно правд нихера =) без субтитров