M6-501 milling attachment for Atlas 6" ??...

[pontiac428]

You don't necessarily need to use a horizontal cutter for the flats. You can make a facing cut with an end mill. Then you could, without moving the part from the milling attachment vise, rotate the vise around to do the plunge cut as wa5cab describes.

You probably don't have to worry much about indexing for this part. If you can hold it firm, you can machine it. At the end of the day, the AK will fire whether you make your mark or miss it by a mile. The photo of your part examples and the wide margin of tolerances proves my point. If you get the features positioned within 0.010" of where they "should" be, you're probably way ahead of the factory in Izhevsk, which has been fueled on vodka for 60 years.

 

[wa5cab]

The parts are smaller than I was thinking. I went back and looked at your photo showing four different makes of the part and this time noticed that there was a dimension shown.

Another type of cutter that would be less expensive than the arbor to hold a standard horizontal mill cutter and is probably available in sizes large enough for your purposes is called a key seat cutter. Look that one up. It has a round shank or shaft typically of a diameter between 3/16" and 3/8" with what may look like a small but thick saw blade on the end. Or like a miniature version of the arbor and milling cutter I mentioned earlier. You would hold it with either a collet or a spindle drill chuck. You could if necessary have the cutter on the end ground to the proper thickness to cut the notch.

But to answer your last question, you might be able to lock the part in the vise with its axis exactly parallel to the spindle axis such that you could cut one wrench flat with the vise bolts horizontal and pointed toward the operator and then rotate the vise so that the bolts pointed to the rear and cut the second wrench flat 180 degrees from the first. But the only notches that you could cut like that would be round bottom. not flat bottom. For which the detent pin would have to have a ball end, not flat.

If you rotate the entire milling attachment 90 degrees so that the vise is on the operator's side of the attachment, you could cut flat-bottom notches with an end mll with the vise bolts pointed up, and toward the tailstock. Whether you could cut the other two notches without the bolts striking the headstock or bed, I don't know.

 

[56type]

You don't necessarily need to use a horizontal cutter for the flats. You can make a facing cut with an end mill. Then you could, without moving the part from the milling attachment vise, rotate the vise around to do the plunge cut as wa5cab describes.

You probably don't have to worry much about indexing for this part. If you can hold it firm, you can machine it. At the end of the day, the AK will fire whether you make your mark or miss it by a mile. The photo of your part examples and the wide margin of tolerances proves my point. If you get the features positioned within 0.010" of where they "should" be, you're probably way ahead of the factory in Izhevsk, which has been fueled on vodka for 60 years.

Yeah, that pic of various countries version of the part is kind of my reason for making my own. The Polytech/Norinco chinese version of the thread protector/muzzle nut is a bit longer than standard & hasn't been imported for 30+ years so finding them is getting difficult.

Another country's version will fit but you have to pick which end you want to look wrong as the others won't completely cover the threads as intended and leave a gap between the front sight base & the nut, or exposed threads at the muzzle. I thought making a few would be a good first project for me as well as allowing for indexing the initial notch that the pin will lock into to the rifle for best fit. Good practice for getting some basics for making different ones.

Even though it's not a critical part I didn't want to start off making a part out of spec. if I could help it.

 

[56type]

The parts are smaller than I was thinking. I went back and looked at your photo showing four different makes of the part and this time noticed that there was a dimension shown.

Another type of cutter that would be less expensive than the arbor to hold a standard horizontal mill cutter and is probably available in sizes large enough for your purposes is called a key seat cutter. Look that one up. It has a round shank or shaft typically of a diameter between 3/16" and 3/8" with what may look like a small but thick saw blade on the end. Or like a miniature version of the arbor and milling cutter I mentioned earlier. You would hold it with either a collet or a spindle drill chuck. You could if necessary have the cutter on the end ground to the proper thickness to cut the notch.

But to answer your last question, you might be able to lock the part in the vise with its axis exactly parallel to the spindle axis such that you could cut one wrench flat with the vise bolts horizontal and pointed toward the operator and then rotate the vise so that the bolts pointed to the rear and cut the second wrench flat 180 degrees from the first. But the only notches that you could cut like that would be round bottom. not flat bottom. For which the detent pin would have to have a ball end, not flat.

If you rotate the entire milling attachment 90 degrees so that the vise is on the operator's side of the attachment, you could cut flat-bottom notches with an end mll with the vise bolts pointed up, and toward the tailstock. Whether you could cut the other two notches without the bolts striking the headstock or bed, I don't know.

Here's a pic of a drawing of what I was thinking of doing...

The view is from behind the headstock looking thru it toward the tailstock. The operator's side of the lathe is the right side of the page. You had advised against lowering the part onto the cutter so I thought perhaps rotating the the vise in the illustrated manner would allow for indexing all four notches without the need to remove the work from the vise. The two arcing arrows represent the rotation of the vise to account for the how the cutter would approach the work to avoid climbing as much as possible. I numbered the cuts to show the order & feed direction in case those needed additional review to get it correct so as not to stress the machine or work. I'm trying to keep the feed isolated to the cross slide as much as possible to maintain the most rigid set up. Thanks.