Re: Stuck March 22, 2017 01:43AM |
Registered: 11 years ago Posts: 1,277 |
Re: Stuck March 22, 2017 02:03AM |
Registered: 11 years ago Posts: 1,277 |
You know I had forgotten about the double pulleys.Quote
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
Re: Stuck March 22, 2017 03:07AM |
Registered: 11 years ago Posts: 1,277 |
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.Quote
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?
Re: Stuck March 22, 2017 03:43AM |
Registered: 11 years ago Posts: 1,277 |
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?Quote
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 )
Re: Stuck March 22, 2017 04:56AM |
Registered: 11 years ago Posts: 1,277 |
Re: Stuck March 22, 2017 05:16AM |
Registered: 11 years ago Posts: 1,277 |
Re: Stuck March 22, 2017 08:01AM |
Registered: 12 years ago Posts: 1,450 |
Re: Stuck March 22, 2017 05:06PM |
Registered: 11 years ago Posts: 1,277 |
Re: Stuck March 22, 2017 05:46PM |
Registered: 11 years ago Posts: 1,277 |
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?Quote
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]
Re: Stuck March 22, 2017 06:26PM |
Registered: 11 years ago Posts: 1,277 |
Nope, hobby stores around here went out of business as most people here don't do stuff like that.Quote
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
Re: Stuck March 22, 2017 06:40PM |
Registered: 11 years ago Posts: 1,277 |
This tells me (thanks to the grub screws) it would be dead easy sliding the rod through it.Quote
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.
Re: Stuck March 22, 2017 07:13PM |
Registered: 11 years ago Posts: 1,277 |
Re: Stuck March 22, 2017 08:46PM |
Registered: 11 years ago Posts: 1,277 |
Re: Stuck March 22, 2017 09:30PM |
Registered: 11 years ago Posts: 1,277 |
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.Quote
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?
Re: Stuck March 23, 2017 12:08AM |
Registered: 11 years ago Posts: 1,277 |
Re: Stuck March 23, 2017 12:55AM |
Registered: 11 years ago Posts: 1,277 |
Measuring from the top of the 20x20 to dead center of the 5mm smooth rod measures 62.52mm.Quote
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)