Re: Lead screw Project

A delrin nut is made that touches both flanks of the acme leadscrew. Kind of like an interference fit, the steel slightly compresses the delrin, resulting in zero positional error with a change in direction of rotation. The delrin is very slippery and tough and will hold up over an extended period of time. The spring only adjusts for the wear on the flanks of the thread.

Fred Smith - IMService

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Andy Wander <awander@...> wrote:
>
> Hi Fred:
>
> How do you get Zero Backlash on an Acme screw? It's not obvious fromteh drawing or the photo.
>
>
> Andy Wander
>
> -----Original Message-----
> From: CAD_CAM_EDM_DRO@yahoogroups.com [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of imserv1
> Sent: Wednesday, May 23, 2012 1:37 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: [CAD_CAM_EDM_DRO] Lead screw Project
>
> I've been working on a new leadscrew design project. The purpose is to have zero backlash, zero endplay, and zero machining for a home built CNC router type of machine. This kit is designed to be installed on a CNC machine using hand tools such as a drill, file, and Allen wrenches. Desired length is adjusted by simply sawing the leadscrew to the needed length and deburring the end.
>
> Here are some pictures that show the concept. Comments and reactions are sought, here or in private at imserv at imsrv.com
>
>
> Photo assembled:
>
> http://www.imsrv.com/images/304200_Nomach-large.jpg
>
> Drawing:
>
> http://www.imsrv.com/images/304200_Nomach-DRG.jpg
>
> This is a 1/2-10 acme thread with dual thrust bearings, a flex coupling, and a threaded shaft clamp. The thrust bearing preload is adjusted and held between the flex coupling and the shaft clamp. The coupling has a 1/2 bore to mount directly onto the lead screw without any machining. The driver bracket clears the end bracket on the top and bottom so the travel between the motor mount bracket and the end bracket is shortened only by the length of the lead nut.
>
> Available in 1 start or 5 start threads. Starts under $100 without motor.
>
> Fred Smith - IMService
> http://www.imsrv.com
>
>
>
>
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