Chassis Build

[jbolt]

I use G-Wizard for feeds and speeds

 

[MontanaAardvark]

I use G-Wizard for feeds and speeds

+1

A really good program. That and his graphical G-code editor that shows the toolpaths are really worthwhile.

 

[Boswell]

I use G-Wizard for feeds and speeds

Also +1 for G-Wizard and his other applications. Nice Site, Nice application. Although my mist coolant system does not clear chips as quick as G-Wizard thinks and so I often run at a lower feed rate. I probably just have not figured out where to enter my coolant method.

 

[jbolt]

G-Wizard has been worth every penny for time and tools saved.

For the question on the corner radius of the magazine well. Here is a photo of a magazine in the well to show that no broaching was needed. Both the Alpha mag and Accurate-Mag fit perfect.

 

[MontanaAardvark]

G-Wizard has been worth every penny for time and tools saved.

For the question on the corner radius of the magazine well. Here is a photo of a magazine in the well to show that no broaching was needed. Both the Alpha mag and Accurate-Mag fit perfect.

View attachment 242195

Thanks.

I'm more familiar with the AR world (15s and 10s) and "broached mag well" is one of those buzz words they use all the time. The thing is that marketing buzz words usually have nothing to do with reasonable ways to do things. I'd guess it's just faster for a company with a big press to broach the mag well than do a tool change to swap end mills and run a pass into those corners.

The prints for the "standard" AR-15 or AR-10 call out a .062 radius instead of the 3/32 your refer to for the ACIS magazines. I've never tried both ways, but I'd guess that while .062 radius is harder to cut than the 3/32, a 1/8 EM isn't that different from a 3/16 EM if its fed slowly enough.

 

[jbolt]

Thanks.

I'm more familiar with the AR world (15s and 10s) and "broached mag well" is one of those buzz words they use all the time. The thing is that marketing buzz words usually have nothing to do with reasonable ways to do things. I'd guess it's just faster for a company with a big press to broach the mag well than do a tool change to swap end mills and run a pass into those corners.

The prints for the "standard" AR-15 or AR-10 call out a .062 radius instead of the 3/32 your refer to for the ACIS magazines. I've never tried both ways, but I'd guess that while .062 radius is harder to cut than the 3/32, a 1/8 EM isn't that different from a 3/16 EM if its fed slowly enough.

If I was making a thousand of these a day, broaching would be the way to go.

The first iteration was setup for a single stack Wyatt magazine that needs a 1/16" radius. I pre-drilled the corners with a 1/8 drill and did the wall finish with a 3/8 end mill which required filing the remaining cusps. In the at scenario using the 3/16" end mill would reduce the size of the cusps. I know Maritool does not have a 1/8" reduced shank end mill. I'm not sure if one exists and if it does it may not be long enough.

 

[spumco]

I'm using both G-wiz and HSM Adviser. Not sure which one I like better yet, but both have been useful. I'll make a decision in about 6 months when the subscriptions need to be renewed.

Less happy with G-editor as the conversational features are essentially useless unless you're proficient at heavily modifying the post processors or have a bog-standard controller (I'm not, and I don't). That, and some of the conversational functions aren't available despite being displayed on the screen.

Thus far, I've found that the Fusion 360 simulator and the simple editor in my control software suffice for fiddling with the programs I've run - so I probably won't be renewing the G-editor license.

As for broaching a mag well or similar pocket... haven't done it yet, but I've been toying with the idea of making a single-point broach to fit the mill spindle and programming it to walk over in to a corner a 'thou at a time. There are a couple of manufacturers making spindle-mounted broaches that look sort of like toothbrushes with a single cutting edge for doing internal splines or key-slots. They claim that the loads on the spindle bearings when doing small step-overs are significantly lower than for drilling or other normal operations.

I was thinking of carving up a square chunk of tool steel that has a bit of lead, a raked tooth, and a round shank to fit the spindle. Flat sides to keep it aligned in the pocket (with a bit of clearance), and then up-down-up-down as it walks in to the corner to clean up cusps. Spindle off, of course, and it would only work on a through-pocket for chip evacuation.

A servo spindle would be the ticket here for indexing and then I wouldn't need a 'guide' section on the tool - but (sadly) I don't have one of those.

 

[MontanaAardvark]

I'm using both G-wiz and HSM Adviser. Not sure which one I like better yet, but both have been useful. I'll make a decision in about 6 months when the subscriptions need to be renewed.

Less happy with G-editor as the conversational features are essentially useless unless you're proficient at heavily modifying the post processors or have a bog-standard controller (I'm not, and I don't). That, and some of the conversational functions aren't available despite being displayed on the screen.

Thus far, I've found that the Fusion 360 simulator and the simple editor in my control software suffice for fiddling with the programs I've run - so I probably won't be renewing the G-editor license.

As for broaching a mag well or similar pocket... haven't done it yet, but I've been toying with the idea of making a single-point broach to fit the mill spindle and programming it to walk over in to a corner a 'thou at a time. There are a couple of manufacturers making spindle-mounted broaches that look sort of like toothbrushes with a single cutting edge for doing internal splines or key-slots. They claim that the loads on the spindle bearings when doing small step-overs are significantly lower than for drilling or other normal operations.

I was thinking of carving up a square chunk of tool steel that has a bit of lead, a raked tooth, and a round shank to fit the spindle. Flat sides to keep it aligned in the pocket (with a bit of clearance), and then up-down-up-down as it walks in to the corner to clean up cusps. Spindle off, of course, and it would only work on a through-pocket for chip evacuation.

A servo spindle would be the ticket here for indexing and then I wouldn't need a 'guide' section on the tool - but (sadly) I don't have one of those.

There's a fantastic video on YouTube where a guy melts down 5 pounds of aluminum soda/beer cans, then casts and machines an AR-15 lower from them. At one point, he takes a piece of tool steel stock and makes a broach just like you describe. I think he just nibbles into the corner with the broach either in a drill press or in his milling machine.

The video is 19 minutes long, but I can't think of any video that long I've watched that held my attention as well for the full duration.

 

[jbolt]

There's a fantastic video on YouTube where a guy melts down 5 pounds of aluminum soda/beer cans, then casts and machines an AR-15 lower from them. At one point, he takes a piece of tool steel stock and makes a broach just like you describe. I think he just nibbles into the corner with the broach either in a drill press or in his milling machine.

The video is 19 minutes long, but I can't think of any video that long I've watched that held my attention as well for the full duration.

That's awesome. What's more American than making an AR from recycled beer cans.

 

[spumco]

That's awesome. What's more American than making an AR from recycled beer cans.

Maybe buying 80% Sten tubes at Home Depot, but I think you're right on target.