Slitting saw question

[jmarkwolf]

Update:

Thanks for the suggestions everybody.

I was looking for an excuse to use a slitting saw for the first time, but it turns out neither of my R8 slitting saw arbors fit the spindle on my new mill properly. On one, the index pin slot is too shallow and it wont slide in at all, on the other, the slot is not long enough and it is apparently jamming the spindle index pin. Time to upgrade to a US made one.

So I'll just band saw my DRO scale cover and clean it up with a file.

 

[doc55]

Done all the time in machine shops provided you use fine toothed carbide blade and a good wood "pusher".

Yes with a carbide tipped blade no problem. We used to cut aluminum plate that way all the time we also used a router to do radius on part edges. With carbide you can use wood working tools and their higher RPM.

 

[RJSakowski]

I've done a number of these covers. Rough it out with the band saw and finish in the mill. Mount the angle for a facing cut with the finished edge just above the vice jaws and use a 3/4 x 2" block to stiffen the edge. Cut with the end mill off center so the cutting forces are in the direction of the angle to minimize vibration. Cut about six inches at a time then reposition work and continue. You may have to do some blending at the intersections of the cuts, depending on how carefully you set up.

 

[jmarkwolf]

OP here with an update.

I didn't want to wait until I could replace my cheesy slitting saw arbor, so I decided to proceed with the bandsaw, and clean it up by hand file.

Later today and/or tomorrow I'll get the X-axis scale installed. That cover won't require any trimming.

Pic below:

 

[homebrewed]

I think you can mill it, if you cut a slot rather than milling away 1-3/8" of material. Sort of like a slitting saw I suppose. But that way you can clamp most of the 2" side in your vise, and the horizontal side will be pretty rigid. It's just a soft aluminum extrusion after all so the cutting forces should be relatively low. If it was me I'd use something ~.1" thick as a spacer to elevate the top of the extrusion above the vise, then remove it after the angle stock is secured in the vise. Then go to it.

You likely will have to do it in sections (who has a 24" wide vise anyway???) but for a DRO scale cover you don't need a lot in the way of accuracy.

Machine shops wouldn't take this approach because it would take more time and not be perfectly uniform, but you don't have to do it their way. "Perfection is the enemy of good enough."

Mark