Looking for Lead Screws

[Dominick Ferone]

Attached is a picture of our calculations. We are trying to optimize the Rpm, as to not draw to much power and have a good mix of speeed and torque.

[mastachyra]

Igus(FIRST sponsor) has some.

http://www.igus.eu/wpck/2371/drylin_trapezgewindemutter

[asid61]

Originally Posted by Dominick Ferone

Attached is a picture of our calculations. We are trying to optimize the Rpm, as to not draw to much power and have a good mix of speeed and torque.

You are running the leadscrews far too fast. They literally cannot tolerate those kinds of rpms without failing.
There is another thread that I saw a few days ago that had a link to a chart of safe rpms for leacscrews.

[pilum40]

We ordered yesterday from www.Roton.com We used them because I wanted to make sure all parts "mated" the first time rather than having to modify/send it back/wait for right part. We prototype d with smaller lead screws from Igus that we had hoarded from past years. We used Igus' sleeve nut and flange to test. It worked great! We're having a build off between a cable/Modulox modified transmission/CIM lift system and the screw next week. I'll post a video of the build off unless it really sucks badly for both.

Here's what we ordered:

59284 Acme Lead Screw, 1/2 - 10, RH, Steel

89403 Acme Sleeve Nut, 1/2 - 10, RH, Bronze

89838 Flange, Steel

19660 Acme Anti-Backlash Flange Nut, 1/2 - 10, RH, Plastic

[stre0123]

Hello,

I too looked at lead screws for 70", but the critical speed for a long unsupported shaft I calculated to be under 400 RPM which with 1/2" lead which makes it under 3ips. We felt it was not fast enough. Lots for force, but not enough speed.

This is a good reference for calculating force, and critical speed
http://pic-designcatalog.com/images/.../section_3.pdf