Thread: Hour meter plate

Wot no sketch.

I wonder about myself sometimes lol
Stuart

Silly question for my own curiousity - I assume it's not possible to get square corners as you have shown in the centre hole of your sketch straight off the mill? Presumably they will be radiused to whatever the radius of your endmill is, and then you'd need to file them square (or use a slotting attachment perhaps)?

File..... not slotting attachment...... yet
Stuart

I cant see a problem doing it that way. You will get radiused corners on the inside depending on the size of end mill you use. Just make sure you use the right speed and you will be fine.
All the grizzly manuals have this for speed selection which makes it easy to work out.

Dave

To determine the needed RPM:

1.

Use the table to determine the

cutting speed required for the material of your
workpiece.

Cutting Speeds for High Speed Steel (HSS)
Cutting Tools
Workpiece Material ---------------Cutting Speed (sfm)
Aluminum & alloys ----------------------------------------------------300
Brass & Bronze ----------------------------------------------------------150
Copper---------------------------------------------------------------------- 100
Cast Iron, soft --------------------------------------------------------------80
Cast Iron, hard------------------------------------------------------------ 50
Mild Steel------------------------------------------------------------------ 90
Cast Steel------------------------------------------------------------------ 80
Alloy Steel, hard---------------------------------------------------------40
Tool Steel ------------------------------------------------------------------50
Stainless Steel -----------------------------------------------------------60
Titanium --------------------------------------------------------------------50
Plastics ---------------------------------------------------------------------300-800
Wood------------------------------------------------------------------------ 300-500
Note: For carbide cutting tools, double the cutting
speed. These values are a guideline only. Refer to
the MACHINERY'S HANDBOOK for more detailed
information.

Cutting speed table for HSS cutting

tools.

2.

Measure the diameter of your cutting tool in

inches.

3.

Use the following formula to determine the

needed RPM for your operation:

(Cutting Speed x 4) / Tool Diameter = RPM

1440 it is then. Only have 1/4inch ATM
Thanks guys
Stuart

Well it's done and it only took 12 minutes of spindle on time lol.
As you can see I removed the holes as I realized they weren't really needed(which beings me to the point of this post). As there was a greater distance from the screws in the center and the outside edge, the helix angle on the cutter was lifting the sheet up, it worked out ok but if I was doing something similar again I would put four screws around the outside to help hold it down better.
Stuart

That come up good, it looks photo shopped.

Dave

Well thanks Dave, little to much flash on some zincseal from an old pc power supply.
I'll put some pictures of before and after of the wiring cabinent tomorrow.
Stuart