Machining a 1” Plate Welding Coupon

[GT-6 Racer]

I agree with Matt. Tilt the head, Unless you have a large enough tilting vise and room to mount them both on the mill.

 

[erikmannie]

This 6” single angle cutter is not easy to use. Once I get this far in there (see photo below), I can only make a .015” DOC if I want things to keep running nicely.

In these photos, I have some cutting fluid, 100 RPM speed, 8 ipm feed, .011” DOC.

The surface finish isn’t bad, but there is a little chatter.

 

[erikmannie]

I agree with Matt. Tilt the head, Unless you have a large enough tilting vise and room to mount them both on the mill.

I am quickly coming around to that way of thinking, particularly due to the fact that I could make a batch of like 10 of these to make it worth the time to lose and reset the trammel.

The face mill sure makes short work of removing A36 steel.

Having said that, does anybody reading this have an idea for the RPM for the 6” diameter cutter for this application?

 

[erikmannie]

I gave up on that 6” diameter cutter. I don’t want the plate coupon to have a 45° angle, & I don’t think I was using anywhere near the correct speed and/or feed.

I knew it was time to give it up when it was struggling to make a .008” DOC. Maybe somebody reading this has had experience with those large diameter cutters.

This solid carbide single angle cutter has no problems taking a .050” rip. CF, 900 RPM, 13 ipm power feed.




I took a break to go get a drink, & I noticed that this cutting tool is extremely hot!

 

[Cadillac]

Here’s something I made awhile back that works great for angles. It’s 1.250 barstock .750 plate. I made a simple adjustable foot that rest on the moveable jaw of the vice for heavy machining.
I hate having to tilt the head unless necessary.

 

[erikmannie]

Here’s something I made awhile back that works great for angles. It’s 1.250 barstock .750 plate. I made a simple adjustable foot that rest on the moveable jaw of the vice for heavy machining. View attachment 422130View attachment 422131View attachment 422132View attachment 422133
I hate having to tilt the head unless necessary.

That is a sweet tilting fixture plate. Does it ever flex at all? Say, if one were machining at the top of it?

 

[erikmannie]

I was getting chatter with the last settings listed, so I dialed back to .035” DOC, 800 RPM, & the same feed speed (13 ipm).

This picture was taken on my dry spring pass. High speed, slow feed: .000” DOC, 1200 RPM, 7 ipm. It is making almost no chips.



If you notice the shape (cross section) of the work, I need to lower the cutter and try to match that angle. I was trying to describe this above, but now you guys get to see pictures.

Last time, I was able to match it up to about a thou, & then I used an orbital sander to make it perfectly smooth (well, 220 grit). You have to think it is shameful to sand your machine work.

 

[erikmannie]

So this is the best that I can do with matching up my bevels. The passes were as follows: 4 passes of 0008” DOC, one pass at .0006” DOC, & then a high speed, slow feed (1200 RPM, 7 ipm) spring pass.

This is definitely a case where you want to sneak up on it. If I were to have overshot it, I would have had to raise the z-axis back up, & machine down the top bevel however much I overshot the bottom.

I do want my welding surface to be as smooth as glass, so I don’t know what else to do other than to use an orbital sander.

 

[snoopdog]

I aplaud the effort and attention to detail, but when you start talking tenths on a welding coupon............................

 

[erikmannie]

This took 30 minutes & 8 sanding disks. I only took it to 180 grit because it is just a welding coupon, after all.



So more often than not I grind or machine my weld beads, & sometimes I sand my machine work. Food for thought.