What stock to store for mill/lathe work?
 

This past summer we bought a mid-sized manual mill and metal lathe. I've worked on mills and lathes extensively in the past, so I was able to get the appropriate tooling, but I'm having trouble coming up with a list of stock to carry to accomplish most tasks that we would need. So what does your team carry in terms of stock? I know it depends greatly on what you do as a team, but if you could still list what you get, we could use it as a starting point for our team.

Re: What stock to store for mill/lathe work?
 

For the lathe:
- Material to make spacers (PVC pipe works great!)
- Material to make standoffs

For the mill:
- solid aluminum stock (bar and plate of various thickness)
- Other normal aluminum stock your team normally uses


For our situation, it's really not an issue to stop by a local Discount Steel and get whatever we need... and once we get it, we have plenty left over in stock. We've found for our team that having a mill and lathe isn't about the materials you have for it - just about everything we've used on it is stuff we already had sitting around. It's about the increased capabilities it gives you in shaping those materials perfectly or consistently for the robot (for example, it's a lot easier to make 4 standoffs that are all the same length using a mill or lathe than it is to do so with a band saw).

Re: What stock to store for mill/lathe work?
 

For the lathe, we mostly use:
-1" dia. aluminum rod
-2" dia. aluminum rod (less frequently)
-1/2" dia. aluminum rod
-1/2" dia. aluminum and steel hex shaft
-2" pvc tubing
-various other sizes of pvc and delrin.

For the mill we primarily use:
-Aluminum billet
-1"x1"x.125" aluminum square tubing
-1"x1"x.0625" aluminum square tubing
-.25" aluminum plate

Re: What stock to store for mill/lathe work?
 

For the mill:
1x1x1/6 wall box tubing (6061-T6)
1x1x1/8 flange angle (6061-T6)
2x2x1/8 flange angle (6061-T6)
3x3x3/16 flange angle (6061-T6)
1/2 x 1 UHMW bar
1/4 x 4 UHMW bar

Re: What stock to store for mill/lathe work?
 

For us this is a totally loaded question as we've probably used 30 different sizes of stock so far this year, in addition to a bunch of stuff we have stocked that we haven't used yet or have used in the past.

This is what we've purchased this year:

Size Length Alloy Quantity
.090"x48"x144" 6061-T6 1
1"x1"x.125" Tube 24' 6061-T6 4
1"x1"x.063" Tube 24' 6061-T6 7
1"x2"x.125" Tube 24' 6061-T6 3
1"x2"x.063" Tube 24' 6061-T6 6
.75"x.75"x.063" Tube 24' 6061-T6 3
.5"x.5"x.063" Tube 24' 6063-T6 2
.063"x1" Bar 12' 6061-T6 2
.125"x3" Bar 12' 6061-T6 2
.125"x4" Bar 12' 6061-T6 4
.125"x2" Bar 12' 6061-T6 2
.125"x1" Bar 12' 6061-T6 1
.1875"x2" Bar 12' 6061-T6 2
.1875"x3" Bar 12' 6061-T6 1
.1875"x4" Bar 12' 6061-T6 2
.25"x2" Bar 12' 6061-T6 2
.25"x4" Bar 12' 6061-T6 2
.25"x6" Bar 12' 6061-T6 1
.375"x1" Bar 12' 6061-T6 1
.5"x1" Bar 12' 6061-T6 1
1" square bar 12' 6061-T6 1
1"x.25" bar 12' 6061-T6 1
1"x1.25" bar 12' 6061-T6 2
1.25" square bar 12' 6061-T6 1
1.5" square bar 12' 6061-T6 1
1.25"x2" Bar 12' 6061-T6 1
1.25"x3" Bar 12' 6061-T6 1
2"x4" Bar 12' 6061-T6 1
.750"x.063" Tube 24' 6061-T6 3
1" x.063 Tube 24' 6061-T6 3

We also commonly use 1" round bar, 2.25" round bar and a bunch of other rectangular barstock sizes.

Re: What stock to store for mill/lathe work?
 

Cory,

That is an impressive list!

Question for you, is this a typical amount of stock purchased for 254 for a season? I'm looking at some of the quantities and it's pretty daunting. Almost 200 feet of 1"x1"x.063" Tube? That seems to me like a ton!

Maybe it's just the game this year. I'm impressed when my kids work through just 20 feet of 1"x1"x.063" Tube!

Does 254 keep records on an spread sheet of all stock material purchases? Seems like your list was copy paste :)

-Mike

Re: What stock to store for mill/lathe work?
 

I can send you ours, it's similar qty.

We build lots of spares, and tubing gets eaten up fast. We seem to alternate between 2x1 and 1x1 seasons, but easily go through 100' of 1/16" wall each year.

We pay per pound, and it's relatively cheap (free shipping by truck as well).

Re: What stock to store for mill/lathe work?
 

That would be great!

Are you purchasing through Coast Aluminum? We just recently started buying from them and have been pleased with the pricing and next-day free shipping. Just got into the large-quantity production game, so we're still learning :)

Re: What stock to store for mill/lathe work?
 

Yes, we love dealing with them as well.

It's actually cheaper in the long run to order all these random sizes you might not need, and then always have a variety of surplus on hand to design around.

Re: What stock to store for mill/lathe work?
 

Also, for lightweight shafting and spacers, Igus sends out some 5/8" linear bearing stuff every year. 5/8", 1/2", and 3/8" Igus shaft is a staple for us, the ceramic coating makes it really easy to slide through stuff. It is also smoother and holds better tolerance than regular aluminum in our opinion. Its good looking, and easy to machine the inside, just be careful when cutting the ceramic coating. Oh, and lots of 1x1, 1x2, and 1.25x2.5 box tube as well as all sorts of angle sizes (mostly 1x1) are really nice to have.

Re: What stock to store for mill/lathe work?
 

Good to know!

+1 for Coast Aluminum, in one of our first orders we only wanted a 4x8 sheet of .125" 6061, and while they typically sell in 4x12 sheets, they made an exception for us. A great company!

Re: What stock to store for mill/lathe work?
 

This is pretty typical. We have probably 4x this in inventory from previous years in assorted sizes. Some of this will likely last until next year also.

I don't keep an inventory of what we have in stock, but I did make a spreadsheet to organize what I needed to get quoted.

We too use Coast Aluminum. Pricing is pretty good, but after 8 years their truck driver still can't understand that we are not available at 7 AM in the morning to accept deliveries when they show up to the real NASA shop with their metal.

Re: What stock to store for mill/lathe work?
 

To add to the above suggestion:
These are good for shafts and spacers that we use regularly.
.750"x6ft delrin
1"x6Ft delrin
.5" hex 12ft