exxos's Atari, Amiga & retro forum

Reading these last posts I think @exxos should ditch the chair and the bed and just sleep and sit on the floor. What could possibly go wrong :hide:

TheNameOfTheGame wrote: 11 Oct 2023 01:51 Have you considered an exorcism? You may truly be cursed by the ghost of office chairs! (whoever that may be..might be Fred..not sure) :lol:

Yeah my mother and I often say we are cursed as we always get bad luck.

Icky wrote: 11 Oct 2023 07:45 Reading these last posts I think @exxos should ditch the chair and the bed and just sleep and sit on the floor. What could possibly go wrong :hide:

Been doing that as I can't sit on the wooden chair for more than 10 mins :lol: I get arm ache as the mouse is above my head :roll:

My first draft chair adapter block thingy.

It is actually upside down. So the "top hole" in the image is actually where the main pressure of the piston will sit. So the weight of its occupant will be pressing on the top and that force will be transferred to the chair base. Being solidly printed I don't think it is going to compress all that much.

Because the piston is actually tapered the second force will be trying to physically split the hole apart. So the two holes as shown in the front will be M10 bolts. This will fix the block to the existing metal base of the chair and also it will help with the "spreading force" because again while the plastic could be pulled apart, it will be even more difficult to compress, especially since it will be trying to compress against two M10 bolts.

The third force will be the "tilt" of the pison. Where the central the block would actually be the pivot point, and the worst force will be the top and the bottom of the block. This will be solely printed for about 20 layers. The actual inside of the block does not really need to be that strong because the top and bottom would see the most strain as opposed to the inside anyway.


So I cut away internal view would look like this.


In this image you can see the holes of the M10 being next to the piston hole.


Now another force is the left to right bending of the chair. If anything will break it will probably be that because the slot is where the lever is. That currently will be most likely the week is pointing in the construction.

Now I have the original part disconnected I can see the underside and also now see where the original welds broke.


It was similarly as bad on the top before I started welding it. But obviously I could not get at the bottom because the whole block was welded in!

I think it would have been a lot stronger if the inner tube actually butted up to the base of the chair which I intend to do with my plastic block. There would be a lot less pressure from the weight of its occupant and the shearing force left to right etc would have also been transferred to the base of the chair. But how the metalwork is arranged, other than some very puny welds, there was nothing substantial about this part whatsoever!

Around and around she goes. Where she stops, nobody knows... But probably soon :lol:

I think you got a Friday chair, as it looks like the welds were improperly formed from the off, and didn't go all the way around.

This is my oldest chair:
And probably the cheapest, and the weld is a complete 360 with no signs of cracking. I can't see the top, but it's still showing no signs of problems.

My 2nd oldest is almost identical.

I did buy a new chair recently, it's rated for 24hr use and 150+ KG, so if it breaks I'll be very annoyed.

I honestly doubt that 3d printed part will hold out and you'll need a metal equivalent.

rubber_jonnie wrote: 12 Oct 2023 14:41 I think you got a Friday chair, as it looks like the welds were improperly formed from the off, and didn't go all the way around.

I must have had about 20 Friday chairs over the years then as they all broke.

I honestly doubt that 3d printed part will hold out and you'll need a metal equivalent.

Still has to be printed to make sure it all fits.

exxos wrote: 12 Oct 2023 14:46
I must have had about 20 Friday chairs over the years then as they all broke.

Still has to be printed to make sure it all fits.

Agree it needs printing to check the fit for sure, but I haven't even broken one chair over the years, the only failure I had was a leaky gas strut, so I just can't begin to imagine how you break yours :dizzy:

rubber_jonnie wrote: 12 Oct 2023 14:59 Agree it needs printing to check the fit for sure, but I haven't even broken one chair over the years, the only failure I had was a leaky gas strut, so I just can't begin to imagine how you break yours :dizzy:

Back here, not a very good image viewtopic.php?p=90199#p90199 but you can see the collar totally snapped off. Hence welding it. Which broke anyway.

Mother and I just say we cursed as we get nothing but bad luck :(

I mean my carpet cleaning machines pump motor is on its way out again. Have to change the thing every year. They built like garbage regardless where or what brand they are. I can't even figure out how they failing. It's like the shaft welds itself stuck for no reason. The pumphead is all brass. Supposed to be rust and chemical resistant. But they keep failing. I don't think I have ever had anything last for any reasonable amount of time. Everything is just total garbage from new these days and nowhere near fit for purpose. It's a ongoing battle and why I have less and less time for Atari stuff these days.

Then the ongoing one is ball joints on my van. Only the genuine part lasts any amount of time. I've just given up replacing them these days. If it passes MOT then I just put up with the thudding and banging now.

exxos wrote: 12 Oct 2023 15:16

rubber_jonnie wrote: 12 Oct 2023 14:59 Agree it needs printing to check the fit for sure, but I haven't even broken one chair over the years, the only failure I had was a leaky gas strut, so I just can't begin to imagine how you break yours :dizzy:

Back here, not a very good image viewtopic.php?p=90199#p90199 but you can see the collar totally snapped off. Hence welding it. Which broke anyway.

Mother and I just say we cursed as we get nothing but bad luck :(

I mean my carpet cleaning machines pump motor is on its way out again. Have to change the thing every year. They built like garbage regardless where or what brand they are. I can't even figure out how they failing. It's like the shaft welds itself stuck for no reason. The pumphead is all brass. Supposed to be rust and chemical resistant. But they keep failing. I don't think I have ever had anything last for any reasonable amount of time. Everything is just total garbage from new these days and nowhere near fit for purpose. It's a ongoing battle and why I have less and less time for Atari stuff these days.

Then the ongoing one is ball joints on my van. Only the genuine part lasts any amount of time. I've just given up replacing them these days. If it passes MOT then I just put up with the thudding and banging now.

Yeah, that collar is deffo a Friday job for sure. Poor welding both ends, but regardless of how you welded it back, that top end was never welded back too, so would always be a weak point.

BTW, you said the chair has a foot rest, does that mean you never rest your feet on the floor? That could add a lot of extra stress at the top of the gas strut.

As for your pumps, it sounds like bad seals allowing liquid/corrosive chemicals into the motor shaft and causing it to corrode.

While I get what you're saying re ball joints, I wouldn't recommend leaving them, when they fail you can completely lose connection between 2 points, which is never good.