Stuck

Yes, but how would all of those pulleys connect with each other as I am seeing a ton of smooth rods.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

its paint mate, not a scale drawing.

The red is belt

As for the smooth rod, well whats the length of the pulley say 16mm (just measured one of mine) and a bearing width say 5mm. So the shaft lenght of the doubble pulleys (the longest you need) only needs to be about 37mm call it an even 40mm.

If you cant find 5mm smooth rod that is dead straight over 40mm, then no one here can help

Edited 1 time(s). Last edit at 03/22/2017 01:51AM by scottybfg.

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scottybfg
its paint mate, not a scale drawing.

The red is belt

As for the smooth rod, well whats the length of the pulley say 16mm (just measured one of mine) and a bearing width say 5mm. So the shaft lenght of the doubble pulleys (the longest you need) only needs to be about 37mm call it an even 40mm.

If you cant find 5mm smooth rod that is dead straight over 40mm, then no one here can help

You know I had forgotten about the double pulleys.
If I could find this in 16t 5mm bore I could devise to have a bearing on top and bottom and use my 3xmm m5 screw inbetween.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

I think you would pay more for a double pulley then just buying 2 and placing them together on the shaft (or glue them if you wanted to)

So do you see this idea as a better solution to your design problem?

Edited 1 time(s). Last edit at 03/22/2017 02:15AM by scottybfg.

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scottybfg
I think you would pay more for a double pulley then just buying 2 and placing them together on the shaft (or glue them if you wanted to)

So do you see this idea as a better solution to your design problem?

It looks like it will work but I will have to re design how the belts work and print the new design up plus I have to print up the pulley holders.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

Only the motor pulley needs to be 16T, the rest can be anything as long as they are equal. You could even increase accuracy by using higher tooth count for the other pulleys.
( I'm referring to the closed belt scenario )

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o_lampe
Only the motor pulley needs to be 16T, the rest can be anything as long as they are equal. You could even increase accuracy by using higher tooth count for the other pulleys.
( I'm referring to the closed belt scenario )

Motor 16t to first 16t pulley to the next 16t pulley and all other pulleys 20t so 3 16t and 4 20t? How would that help?

Edited 1 time(s). Last edit at 03/22/2017 03:45AM by Dark Alchemist.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

Motor 16T, all others 20T would be fine. The 16T will determine the steps/mm.

You could even use smooth idlers on the far side of the double pulleys. Just make sure they are aligned properly.

Also be reminded, you'd have to clamp the carriers to the same side of the belt.
Either both on left side or both on the right side. ( Not both sides on the inner belt )



Edited 2 time(s). Last edit at 03/22/2017 04:57AM by o_lampe.

"Also be reminded, you'd have to clamp the carriers to the same side of the belt.
Either both on left side or both on the right side. ( Not both sides on the inner belt )" I don't get that part even with graphic.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

Print it out and draw arrows along the belts. Which side of the belts ( inner/outer) will run in the same direction for both carriers?

Heck, if you look at the design I have this will be hell to implement and I will lose a lot of print space which this design was 300x300x370.

I did the paper arrow bit and yeah, one side on the outside and the other on the inside because of the way the belt will move. Interesting concept but I can't see how to do this (due to using wheels mainly) without losing a lot of space in X and Y.

Edited 2 time(s). Last edit at 03/22/2017 05:22AM by Dark Alchemist.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

If I understand your CAD rendering (KKKNXwV.jpg) correctly, the 600mm smooth shaft is to connect two toothed pulleys. My take on this is that it is not necessary to have the rod dead straight as it will bend by a couple of mm under its own weight. It will however be necessary to have two or more supports to hold it in line. These need be little more than PLA bearings with a fairly close but free fit..
The bad news is that a 600mm long 5mm dia. rod will have quite significant torsional flexing - it will twist along its length, particularly if there is any 'jacking" or the carriage ends.
One of my printers has two 6mm bore 20 tooth pulleys which are 500mm apart which I joined with 8mm thin wall stainless steel tube. This is much more rigid than 6mm solid bar both in bending and torsionaly.

Mike

No idea but having the support along it was even worse because none of the four rods were straight. I have to give up on this 5mm rod as I just can't get a length that is straight as even the ends are slightly bent. If I had a way to do it the axle method gives me the most printing area.

Edited 1 time(s). Last edit at 03/22/2017 05:08PM by Dark Alchemist.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

I said it a few times but may have been glossed over, Have you looked at carbon fibre rods? They are used in RC plane building because they are light, strong and offer a small amount of flex.

It sounds like you are dead set on the shaft idea so you dont have to do too much re design, so maybe its time to look at different materials that will give you the shaft you want.

[hobbyking.com]

[www.ebay.com.au]

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scottybfg
I said it a few times but may have been glossed over, Have you looked at carbon fibre rods? They are used in RC plane building because they are light, strong and offer a small amount of flex.

It sounds like you are dead set on the shaft idea so you dont have to do too much re design, so maybe its time to look at different materials that will give you the shaft you want.

[hobbyking.com]

[www.ebay.com.au]

It was way late and I did not check up on the fiber rods as I got enthralled (still am to a good extent) by the all belt AND I know zip about carbon fiber rods. Are they perfectly straight? Will they deform while spinning around (like a rope)? Will they be able to handle tightening of the gt2 belt without bending?

Hobby King is sold out and the ebay link is a maximum of 500mm length but it gives 5mmX3mmX500mm so that means it must not be round due to the 3mm dimension.

Edited 1 time(s). Last edit at 03/22/2017 05:48PM by Dark Alchemist.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

I cant say that they will be perfectly straight (something you would need to ask the suppler) but they will have some flex, so as long as the bearings are aligned this shouldn't be a problem (you might need to add one in the middle depending on the distance between bearings). Its not going to deform when spinning and should take the tightening of the gt2 belt, depending on your supports (you have one each side of the pulley so I see no issue there)

These where just two links to show you, if you have a local hobby store go ask if they have any, even if its just a small section to have a look and see if you like the material

Also the ebay one is round, just a tube so 5mm outer 3mm inner and 500mm long

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scottybfg
I cant say that they will be perfectly straight (something you would need to ask the suppler) but they will have some flex, so as long as the bearings are aligned this shouldn't be a problem (you might need to add one in the middle depending on the distance between bearings). Its not going to deform when spinning and should take the tightening of the gt2 belt, depending on your supports (you have one each side of the pulley so I see no issue there)

These where just two links to show you, if you have a local hobby store go ask if they have any, even if its just a small section to have a look and see if you like the material

Also the ebay one is round, just a tube so 5mm outer 3mm inner and 500mm long

Nope, hobby stores around here went out of business as most people here don't do stuff like that.

You know it was so bad with the 5mm rods that I had to remove the outer holder on each side or it would not work.

There is one issue I found that disturbs me but how do you get a 5mm rod into a 5mm bearing???? I had to spend 2 hours sanding my rods to try each one but on a Carbon fiber rod I don't think I would want to sand that from what I have read. It amazed me that a bearing made for 5mm wouldn't be 5.1mm to allow the 5mm rod to go in but none of my 625zz were anything but 4.9-5.0. Thinking back none of my Prusa stuff was a smooth rod going into bearing they were always screws which are always slightly less than the rated M size so never an issue. Would be like me taking an eight mm smooth rod g6 and trying to slide a 608zz bearing on it. If the 5mm 625zz is how all of them work it would never fit.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

Yeah been there, but 5mm rod goes nice into 5-8mm couplers, and 8mm rod goes easy into the 8mm pillow/self aligning bearings.
So much neater than a plastic part.

Edited 1 time(s). Last edit at 03/22/2017 06:35PM by MechaBits.

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MechaBits
Yeah been there, but 5mm rod goes nice into 5-8mm couplers, and 8mm rod goes easy into the 8mm pillow/self aligning bearings.
So much neater than a plastic part.

This tells me (thanks to the grub screws) it would be dead easy sliding the rod through it.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

these might be better for your frame. you can pass extra length out the ends.

Edited 1 time(s). Last edit at 03/22/2017 07:08PM by MechaBits.

Harder to attach those to the 20x20 extrusion whereas the ones I showed I can print a minimal tower then 3 holes but that one (the one I always think of when I hear the word pillow block) I would have to have a column that is attached to the 20x20 then go up and have two opposing holes from the first set to attach the block. So, two sets of holes 90 degrees opposite the first set at the bottom of the column.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

If you want to go back to the belt idea, I made it simpler and would fit to the top with only a few part modifications and no loss in print area.


By mounting the motor ontop you save belt and space, as for mounting the belt to the carriage just add a bracket to the top of your carriage design, and insted or just using one plate, use two (one on each side of the wheels, that way the have a tab on both sides (as one x carriage will need to be mounted to the inside of the belt and the other x carriage will need to be mounted to the outside)

Edited 2 time(s). Last edit at 03/22/2017 08:05PM by scottybfg.

The parts I circled in red are where I am having an issue with designing and making fit. The other is I can't change the plates and they can't change how they are printed so I am trying to come up with a way to get the belt around it since those big honker wheels are there.


Edited 2 time(s). Last edit at 03/22/2017 08:48PM by Dark Alchemist.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

Are these the plates you cant change? If its all 3D printed apart from the 20*40 why cant you change?

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scottybfg
[attachment 92295 addon1.jpg]

Are these the plates you cant change? If its all 3D printed apart from the 20*40 why cant you change?

Not those being the ones I can't change it is the ones with the wheels. Those you circled would be swapped out but I am not sure how I would design those that I circled in red to not be funky.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

Yeah ok.

I had envisioned an almost cube bracket with two side faces missing to allow for the belts to pass through. With out dimensions of your parts (pulley, motor bearings) I cant do much else.

No problem I will have to work something out myself.

Thanks for the help you did provide.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

Nah, Im stubborn (if you cant tell already). I got most the distentions from a quick google, Just need one more you. What height is the centre line of that 5mm shaft currently?

With the rest of the numbers I found the bracket almost designs itself, If you give me this last dimension ill send you a solidworks file, (yeah, no more shitty paint haha)

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scottybfg
Nah, Im stubborn (if you cant tell already). I got most the distentions from a quick google, Just need one more you. What height is the centre line of that 5mm shaft currently?

With the rest of the numbers I found the bracket almost designs itself, If you give me this last dimension ill send you a solidworks file, (yeah, no more shitty paint haha)

Measuring from the top of the 20x20 to dead center of the 5mm smooth rod measures 62.52mm.


Edited 1 time(s). Last edit at 03/23/2017 12:58AM by Dark Alchemist.

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I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.

I'm afraid even with a carbon rod, you'll need one flex coupling.
But it seems we are back to the belt idea?