Minimum mill size for 308 lowers

[Junkie]

http://sherline.com/product/50005100-mill/ I found a good deal on one of these, converted to CNC. Travel 8.65x3.00x6.25, 8" clearance table to spindle. Obviously with a small aluminum mill like this I would have to take relatively small cuts with a fairly small end mill, but is it large enough to do a 308 lower?

I suspect it'll be adequate for 1911 rails, right?

[kcstott]

I'd only use that if i had to. that thing is barely able to engrave a lower let alone have the reach to go to the bottom of the FCG pocket

[milotrain]

relatively small cuts with a fairly small end mill

Understatements are funny.

They are FANTASTIC mills for model and clock makers.

[baih777]

I actually have one. I did a few lowers.with it. Even making cuts .005 at a time it seems like forever. Bigger cuts you start to get too much vibration. Its not designed for this type of work. Its really hard on the machine. The repeatability for accuracy is not there. Its great for modeling and R/C .
Look at the bigger Grizzly mills.

[Junkie]

Space/weight is a concern, which is why I was considering it. I don't trust the floor in my work space to support a 600lb mill/drill, if I did I'd have bought one quite a while ago.

I don't really have any CNC experience. Is there some reason I can't set it up with a carbide end mill, a ducted shopvac to keep chips clear, press go, walk away, come back a couple hours later? Obviously this is a home shop, not a production environment.

On the other hand, it sounds like it might just be too small.

[kcstott]

Space/weight is a concern, which is why I was considering it. I don't trust the floor in my work space to support a 600lb mill/drill, if I did I'd have bought one quite a while ago.

I don't really have any CNC experience. Is there some reason I can't set it up with a carbide end mill, a ducted shopvac to keep chips clear, press go, walk away, come back a couple hours later? Obviously this is a home shop, not a production environment.

On the other hand, it sounds like it might just be too small.

you could if you knew speeds feeds and not to use carbide or at least use a grade and grind of carbide made for aluminum. sure set up a pocket with 5% offset and .005" doc sure.

What kind of floor you got?? you could load test it just hang out at the bar till 2AM, pick up that fat chick that would make a freight train take a dirt road, get her home and have her dance around, if she don't fall through a 600 lb mill ain't going anywhere.

[liber]

you could if you knew speeds feeds and not to use carbide or at least use a grade and grind of carbide made for aluminum. sure set up a pocket with 5% offset and .005" doc sure.

Actually might be possible on the Sherline. It has 3" of depth, from his numbers and you only need 1.249". That is after getting it setup.

What kind of floor you got?? you could load test it just hang out at the bar till 2AM, pick up that fat chick that would make a freight train take a dirt road, get her home and have her dance around, if she don't fall through a 600 lb mill ain't going anywhere.

Thanks for painting that picture...LOL

I saw there was a Nichols horizontal for $100 on craigslist and a Kent Owens horizontal that's been listed. Horizontals take a bit of thinking to fixture properly...if I was you, I might be looking at trying to get this for $600-$750. Cash talks, doncha know?

This is not too big, if the bar gal can dance on the floor it would probably hold this...

http://goldcountry.craigslist.org/tls/5637496366.html

EDIT: Even this would be a heck of a lot better than a Sherline:

http://sfbay.craigslist.org/nby/tls/5634987555.html

[Junkie]

The fact that the Sherline is already set up for CNC is what's tempting (as I imagine I can find files for ARs and 1911s).

It's a shed, I believe from the 20s, that for some reason has an elevated wood floor. It's squishy enough in places that I had a bookshelf (with some parts but nothing that heavy) fall over. I know, not good, but it's what I have. I have no clue why it isn't on slab, but it isn't.

[baih777]

This Grizzly mill is only 395lbs. With DRO. It is not CNC. You should check the Sherline website and see how much it costs to convert the one you wanted to CNC.

I did a few lowers with my Sherline. After 2 i had to adjust the backlash. I have the DRO. I gave up trying to use it. The vibration is just too much for the mill.

[ar15barrels]

It's a shed, I believe from the 20s, that for some reason has an elevated wood floor. It's squishy enough in places that I had a bookshelf (with some parts but nothing that heavy) fall over. I know, not good, but it's what I have.

Put in a new wood floor.

I had my 1200lb 12x36 lathe on a wood floor in my first workshop.

[valley82]

I have done quite a few lowers with one of these mounted to a solid workbench...http://littlemachineshop.com/product...ory=1387807683

Works plenty fast enough for a hobbyist...I wouldn't try to do production runs with it but it is plenty for what I do with it.

I know, I know, KC you would rather rebuild a mosin than mill anything on my "little toy"

[kcstott]

I have done quite a few lowers with one of these mounted to a solid workbench...http://littlemachineshop.com/product...ory=1387807683

Works plenty fast enough for a hobbyist...I wouldn't try to do production runs with it but it is plenty for what I do with it.

I know, I know, KC you would rather rebuild a mosin than mill anything on my "little toy"

Everything has it's purpose, using something outside its purpose is ok as long as you understand the limitations. Back in the day all i had was a hack saw a set of files and a small bench vise on a old kitchen table.

it worked but there was motivation to upgrade. that was 24 years ago...Wish I had pictures of that shop.

I use to have my RL550B bolted to the top of a filing cabinet in my apartment... that was 25 years ago.

[Junkie]

Put in a new wood floor.

I had my 1200lb 12x36 lathe on a wood floor in my first workshop.

If I owned it, I absolutely would. I don't. It's at my mom's house (10 miles from where I live), she doesn't want to spend the money, and I'm not willing to put the money/work into something that isn't mine.

I do have some heavy stuff in there - a Reed 106, my YZ426 supermoto, etc - but I can't imagine a mill doing well if it tipped over. I also think she'd be rather upset at a mill-shaped hole in the floor if that happened.

[Junkie]

Actually might be possible on the Sherline. It has 3" of depth, from his numbers and you only need 1.249". That is after getting it setup.



Thanks for painting that picture...LOL

I saw there was a Nichols horizontal for $100 on craigslist and a Kent Owens horizontal that's been listed. Horizontals take a bit of thinking to fixture properly...if I was you, I might be looking at trying to get this for $600-$750. Cash talks, doncha know?

This is not too big, if the bar gal can dance on the floor it would probably hold this...

http://goldcountry.craigslist.org/tls/5637496366.html

EDIT: Even this would be a heck of a lot better than a Sherline:

http://sfbay.craigslist.org/nby/tls/5634987555.html

I'm kinda tempted on the first. It'd end up in my aunt's garage 40mi from here rather than 10mi, but I imagine it'd work better...

[liber]

I'm kinda tempted on the first. It'd end up in my aunt's garage 40mi from here rather than 10mi, but I imagine it'd work better...

Yeah, that first link looks like a decent setup, but you need to find out about tooling and/or if it's common or not. That could make a mill very attractive, if it had common tooling.

That Nichols for $100 is quite a deal. You can find vertical heads for them, but they don't go too cheap. Still, if you can get a vertical head for $600 you would only have $700 into it. Those have NMTB 40 in the spindle, very common and tooling can be found very cheap on ebay. With the vertical head it's a very stout machine and the footprint is small, like 2'x3'.

I know a guy who does lowers on a Pratt Whitney horizontal mill. It does take some thinking to use a horizontal, since you have to work from the side, but it is doable. The Nichols is 3 phase, something to consider. You would need to check the first link and see what phase it is. The Grizzly is definitely single phase. That says it has R8 and R8 tooling is cheap also since most Bridgies have R8.

Good luck with your choice, I just spent $800 for a new vise. Tooling is a money pit. LOL