nema 17 machine and thicker screws 🇬🇧

28 May 2020 11:26

I know that the original files call for a t8 screw to be utilised... 

I am going big... 1500x1500 and believe that there can be a lot of whipping as the screw travels its full length...

obviously, a thicker screw would be ideal... 

I have seen on https://www.motedis.co.uk/shop/Dynamics-linear-units/trapezoidal-threaded-spindle-accessories/trapezoidal-threaded-spindle/Steel-Trapezoidal-threaded-spindle/Trapezoidal-threaded-spindle-RPTS-right-TR-10x2-L%3D1980mm::999994793.html a t10 with a 2mm pitch with an 8.7-8.9 min max lead...


or even the https://www.motedis.co.uk/shop/Dynamics-linear-units/trapezoidal-threaded-spindle-accessories/trapezoidal-threaded-spindle/Steel-Trapezoidal-threaded-spindle/Trapezoidal-threaded-spindle-RPTS-right-TR-12x3-L%3D1980mm::999994801.html

a 12mm with 3mm pitch and a 10mm lead...


If i make the holes bigger on the parts... can these be used..?

Especially seeing that they are so much cheaper...?


Thanks in advance

28 May 2020 12:14

With the T8's and their 8mm of movement, Ive been offered T20x45 ball screws... £120 a length of 1500mm... with such big distance per revolution, would this hinder the motors or help them...?

28 May 2020 15:50

@jason higgins I build mine with the screw from Motedis, the TR 12x3. I have used 12mm bearings and modified the holders for the bearings and for the nut holder (the nut is also from motedis). My machine is 1100x1500. I did not finished the machine, I think saturday I will have the fist test, I will write here my experience with the behavior of the lead screws.



30 May 2020 10:04

I think your issue is the 3mm pitch...

You motor needs to do a full revolution to move 3mm...

I know they are expensive, but I’ve also sourced a 12mm speedy screw with a 35mm lead... I think this will put so much less pressure on the motors.... 

imagine how easy it will to calculate the steps...


Can someone confirm?

02 Jun 2020 00:36

someone on here must know an answer...?

We cant all be waiting for Topsy to get involved in every post...

02 Jun 2020 11:16

In the Nema23 version I thought about using larger lead screw up to 12mm.

In the Nema17 version it's a bit more complicated, which version do you plan to make ?

02 Jun 2020 12:08

Hi Topsy,

Gotta say - loving your work!!!

I'm going to do the Heavy Nema 17... I don't want to have half Nema 23 and 1 piece of nema 17 so I'm gonna stay with 17..

I understand that increasing the screw diameter changes a couple of components... and the arduino programming - as i will have to tell the board that the lead will be 35mm instead of 8 as you do in the video...

The question is, i saw on one of your posts about using a t8x2 and it was sooooo slow... if I can get hold of these Speedy Screw 12x35 lead... it would work well... or badly..?

02 Jun 2020 21:28

it would work but you cant mount it on the nema 17 version :/ 
there is no place to use a T12 screw with his nut

03 Jun 2020 12:23

(which nut)

Id obviously have to find a way of mating the a 12mm screw to a Nema 17... and I'd have to change the T8 nuts to T12's and make holes bigger on your STLs..?


J

03 Jun 2020 13:38

Hi Jason,

Check this, i don't know if it's you're looking for... :)

5mm to 12mm

03 Jun 2020 14:14

David..!

awesome..!!

I'm going to have a proper look through this site as well..!!

cheers..

I still want topsy to confirm what  he means by 'nut' I assume its the motor to screw nut..

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