Which Lead Screws to buy?

[finsel]

Hi,

I have no Idea which Lead Screw to buy, or use, etc...
There is a calc for choose the best? what else ?
Someone have some example of stuffs cut with some Lead Screw , etc ?

Thank you!
Frank

[Boort]

Frank,

What lead screws you want depends a lot on what you are planning to use your router for.
On my "Stock" model A router I have used:
10" 1/2-10 Acme threaded rod for Z Axis
18" 1/2-10 Acme threaded rod for X Axis
24" 1/2-10 Acme threaded rod for Y Axis
This works well for my v-carving and general woodworking projects and would probably work well for some larger jewelry type projects.
If you want to mill objects with lots of fine details (Most Jewelry, milled Circuit boards, etc) I would suggest getting screws that have a finer pitch and/or multiple thread starts. For example I have heard that milling circuit boards using ACME 1/2-8, 2 Start (4 Turns Per Inch) coupled with larger 280 Oz In. stepper motors works well.

I hope that this helps.

Regards,
BoorT

[finsel]

Hey BoorT,

Thank you for your answer I really appreciate it and was very usefull for me.
Also, do you have some pictures from your router with lead screws identifications? If it is possible, show me the details of them, connection that you made to fix it to the mdf, etc..
Ps. I write 2 others topics in forum.. if you have their answers or comments, I appreciated too

Thank you!
Frank

[Boort]

Frank,

I have pics up in my album showing my machine. Only a few show the lead screws due to a problem I had when my y-axis lead screw was not aligned with my rails. It rubbed on the bottom of my table and caused binding at one end of the axis travel. I will see if I can get some better pics of the router this weekend.

My Model A is basically built to the plans. The lead screws are not really mounted to the base of the machine. On one end they are attached to the Motor which is mounted to the frame, in the middle it is attached to the Axis by the nut. On my machine the lead screws other end is left floating free. This is per the plan, others who have built routers with longer travels have often fixed the far end of the lead screw to the frame with a collar and bearing, or single point system (like the live center on a lathe) to keep it from whipping about.

BoorT

[Boort]

Frank

Here are the pics I mentioned yesterday.

The "X-ZAxis_ConnectorPlate_ShowingLeadScrewAndABNut.sml. JPG" file shows the X/Z connector plate and the antibacklash nut that connects it to the Xaxis lead screw. This provides the "East/West" movement of my router bit.


The "Yaxis_FloatingScrew.sml.JPG" picture shows my yaxis table, it's rails, and the floating end of the lead screw. The table provides the "North/South" movement of the part. Since I did not make my router any bigger than dictated by the Rockcliff plans I can get away with not fixing the ends of my lead screw. So far I have not had any whipping problems.

The "Yaxis_MotorMount.sml.JPG" Picture shows how I mounted my motor on the other end of the y axis. Here you will seean extra piece of 3/4" plywood compared to the plans. This is because when I was gluing up the mount that is labeled it slipped and caused my lead screw to be out of plane with my yaxis guide rails. This situation caused binding of the leadscrew on the underside of my table. I fixed the problem by unmounting the motor, disconnecting the leadscrew, and gluing on a new plate which held the motor/lead screw in correct alignment.

I hope that this helps. Let me know if you have any questions.

BoorT

[finsel]

Hi BoorT,

Very nice pictures! It will be very usefull on my construction!
Today I just finished to format one old computer to be used. Next week I will receive my 4 stepper motors, power source and module. (http://cgi.ebay.com/4-Axis-Nema-23-S...item27b2d7c1b1) or http://www.wantmotor.com
And next week I will see the price of the lead screws and decide which cnc build...
I have no plans to what I will cut.. it is only a hobby.
Any doubt I will post..

Thank you
Frank