ADA: Ask Doc Anything!

[Siress]

Whats the proper terminology - if I need an oring groove cut into a cylindrical object, are you milling or machining the groove?

You didn't ask me, but in the set of all things 'machining' exists both 'milling' and 'turning'. As such, 'machining' is the most correct answer between the two options. It also covers others methods of cutting o-ring glands that you didn't mention. (e.g. sinker EDMing) I say glands because they have particular features that grooves do not necessarily have.

And I want to share the absurdity I have to live with - but not to be a smartarse to Doc: what if it's a lathe with live tooling and I've got my flywheel cutter in the chuck holding a grooving tool just right while the part is spinning in one of the live tool holders.. What then, eh? other than carbide fragments everywhere...

[Target]

How useful would this lathe be for non industrial stuff.? Its an American Tool Works unit, 16" swing, 76" bed ,single phase

[DocsMachine]

How useful would this lathe be for non industrial stuff.? Its an American Tool Works unit, 16" swing, 76" bed ,single phase

-My common answer is that any lathe is better than no lathe. There was a time not all that long ago that I'd have killed and helped hide the body for such a machine. My first lathe was a Grizzly 9x20, and after that a Logan-Made Powermatic. That latter one had a spindle speed that might have achieved 600 RPM, downhill with a tail wind, and had no screwcutting or quickchange gearbox. Nonetheless, I still made some pretty decent parts on it.

On the pro side, it's a screwcutting lathe, power cross and traverse, and has apparently plenty of accessories including what might be three chucks (or two and a faceplate) a steady rest, tools and toolholders, etc. The ways don't look too worn, it doesn't appear to have been beat to death, and appears to be ready-to-go functional. (With a good cleaning and oiling.)

On the con side, it's got plain bearings and a cobbled belt drive, which will limit the top speed. Probably to less than 500 RPM. This is not a fatal flaw, of course, but is a limitation. Possibly worst of all, it probably has a now-obsolete spindle thread, meaning to adapt any other chuck will mean having to make ones' own backing plate. It may also have what is today considered an absurdly small spindle bore, like 3/4", though it could have as big as an inch. It's not impossible it has no hole through the spindle at all, but I think that's "new" enough- relatively speaking, of course - that's probably not the case.

If it's not too expensive, you have the room for it, and are willing to work around the limitations (and no better machine is available) I'd say grab it. ATW was well-regarded, later developing the nigh-legendary Pacemakers, possibly the epitome of American-made manual lathes.

If you DO get it, several things to keep in mind: There's no chip or drip tray, and machines like that [i]live[i] in oil. As I said in an earlier post in this thread, you can't over-oil a machine like that- at least, not 'til you start noticing your socks are getting squishy. The common trick is to find a sheetmetal guy or HVAC shop and have a pan made up, big enough the legs can just sit in it. That'll catch the drips, chips and other gunk, and keep from staining your floor.

The spindle especially needs to be constantly oiled- keep oil in the glass- and use the correct oil. Any oil is better than no oil, but the right stuff is best of all. It's been a while since I looked into plain-bearing oils, and such is not my forte`, so you'd want to do a little research.

Apart from that, keep the ways clean, oil the bejeebers out of it, and pick up a copy of South Bend's How To Run A Lathe. Have fun!

Doc.

[XEMON]

While on the topic of spindle bore size ... What's the smallest lathe with 1+" spindle bore?
I'm super limited in space ...

Thanks DOC 👍

[DocsMachine]

While on the topic of spindle bore size ... What's the smallest lathe with 1+" spindle bore?

-Smallest? Sherline either makes or used to make one of their little tiny lathes that actually took 5C collets. They even had a gang-tooled CNC version.

More realistically? Look for a Southbend, 9" or 10", an 11" Logan, or a 10" Sheldon. I'm sure there's others, but any of those are available with a big enough bore to take a 5C drawtube. (About 1-3/8".) Out of the three, an 11" x 24" Logan would likely be the absolute most compact for you, though an 11" x 32" will be more common to find, and not that much larger.

Doc.

[XEMON]

Dam ... A 5C shereline 🤯
11X24 or 32 would be great, but I've looked at a few that had 3/4" bore 😒

So if it takes 5C it got ~1"3/8 bore?

[un2xs]

I dont remember seeing you answer this one before, but i did not go through all 24 pages of previous posts.

What is the best form of rollout prevention for old guns? Does it matter which type of guns... i.e. brass guns candidates for Wedgits? Or perhaps unibody vs removable barrels?

[DocsMachine]

There's no one best method. It depends on the gun and how far you need to go. (IE, how small your paint is.)

Generally speaking, I tend to prefer something changeable or removable- that is, I'd prefer an insert or sizer, or tape or nail polish, rather than actual dents in the barrel or the like. That's because the paint is still too variable in size- and, if we're lucky, the makers will start bringing it back up at some point.

For anything with a removable barrel, tape, nail polish or even one of FreeDummy's rubber inserts will work just fine. There's no Big Secret to it, just something that will hold the ball more or less in place for a few moments.

For a common barrel, ideally a Freak or iFit system is the best choice, in my opinion. Yeah, it's not perfect, considering that even the smallest Freak inserts are starting to be too big for some paints, but one idea there I'm not sure I've seen anyone try yet, is wedgits on an insert. Maybe take a common and easily-replaced insert like a .686" and put some wedgit dents into it.

The tricky ones are the fixed barrel guns, like unibody Phantoms, Bushmasters and Wintecs. The nail-polish thing is probably the easiest, using a small brush maybe taped to the end of a popsicle stick or shish-ka-bob skewer or something. (Drinking straw, disposable chopstick, forceps, whatever works. Takes good lighting and a steady hand, but can be done and is of course reversible/removable.)

Doc.

[XEMON]

but one idea there I'm not sure I've seen anyone try yet, is wedgits on an insert. Maybe take a common and easily-replaced insert like a .686" and put some wedgit dents into it.

Doc.

I've been thinking about trying it for a wile, i got an insert with a huge bore so not a big loss if i mess it up ...

Also, i did this to my bushmaster to prevent rollout:

[Jordan]

I've done nail polish detents in Freak inserts - they worked - so I'm sure wedgits would too, just a matter of figuring out how to avoid destroying the insert.

[XEMON]

I was thinking about making an insert (machined or 3d printed) to "hold" the insert and preventing it from collapsing ...

[jeramiej]

Doc, how is the “Duke” going? A very impressive build.

looks like insert link loses the page, here: http://www.docsmachine.com/projects/lever/mk2-01.html

[DocsMachine]

Doc, how is the “Duke” going? A very impressive build.

-Okay, without making a huge wall o' text out of it:

One, yes, I very much plan to try and produce a run of Dukes. The size of said run is still up in the air, but I'm doing what I can to bring it around.

Two, things that have been holding me back include, but are not limited to, time, funds, the physical ability to make the parts (in economic quantities) and time. It's also worth noting that I designed the gun around easy-to-get and inexpensive Phantom parts... which at the moment are neither. I can make the stuff if I need to, but that just adds to cost and time.

Three, last year I borrowed heavily and bought a couple of my own damn CNC machines, both to speed up day-to-day production, which should, I strongly hope, also help with the income bit, but also to produce the Duke parts themselves (rather than having to farm them out to flaky third-party shops.)

All that said, I can give no hard ETA, and I absolutely will not be taking any down payments of any kind, until I have parts on the table.

IF anyone would like to help, finances are and always have been, the biggest rock in the road. A few bucks a month toward my Patreon would be one of the easiest ways- the income from that is basically the only thing that got me through 2020. There's also my eBay store and my badly-in-need-of-updating online store.

Thank you.
Doc.

[flyweightnate]

Do you prefer selling through ebay, or your site to save fees?

[MrBarraclough]

Are the margins better for you via your online store or eBay?

If you can produce Timmy/Spyder detents and Angel A-1 detents, how about PE Ego/Etek detents?

[jeramiej]

Great update Doc. 2021 and 2022 finds your roadblocks are common with many.

[un2xs]

Why do tornados hate trailer parks?

More on topic for MCB: What is the one paintball gun you have built or modified of which you are most proud? Basically the one that gives you warm fuzzies when you say, "Yeah, I built that."

[MrBarraclough]

I bought one of your Automag barrel adapters from you directly and later got a used one from Superman to give a buddy. The one for my buddy has "Docs Machine" engraved on the side (or maybe "docsmachine.com" or similar) and fits slightly loosely in his mag body. There is just a teeny amount of wobble you can feel when you grab the barrel. Mine is perfectly snug. It doesn't seem to make any practical performance difference. Is my buddy's one some kind of prototype or earlier production run? Potentially relevant detail: He's using his original classic mag body while I am using a polished steel minimag body.

[DocsMachine]

What is the one paintball gun you have built or modified of which you are most proud? Basically the one that gives you warm fuzzies when you say, "Yeah, I built that."

-That's kind of hard to pin down. There's been more than a few guns I made that I'm proud of, not necessarily because of how stunning the end result is, but how well the actual work came out.

For example, one of my all-time favorites is this gun:



Compared to hundreds of more modern guns, it's really not all that spectacular. BUT... that started out as a side-feed body, which I milled out, and then fitted that block. Which fit perfectly. To the point where when I got the parts back from anno, I had to slightly warm the body to slide it in- it's not a press fit, but it's damn close. Better still, I fitted the top tube so that when the block is bolted down (you can see the dots of the two tiny stainless screws) that "clamps" the feed tube in place.

Moreover, I did that on a worn-out mill-drill, very few endmills, using a sh***y drill press vise, in the first year I as in business, and with all of about half a week of actual machining experience under my belt.

For one where the result came out well, as well, I've always been fond of this one:



Wasn't happy with how the Freak back came out, but I love the grip frame, which was 100% from scratch, including the trigger and sear.

It's also worth noting that I have done relatively few "full custom" builds in the last... well, quite a few years. I've repaired tons of them, done minor mods or upgrades, made thousands of parts, etc. but not that many 'complete' markers.

That said, I'm kind of proud of how the Duke came out, too...

It doesn't seem to make any practical performance difference. Is my buddy's one some kind of prototype or earlier production run?

-It happens. The industry term is "stacked tolerances". Generally speaking, my adapters- and yes, I've done dozens and dozens of separate runs- are within about 0.001". From 0.9995" to 1.0005". Automag bodies are a little wider than that- I've measured them from 1.002" to 1.005", with most of them being on the lower end.

Really, without hand-fitting, or making the insert a press-fit that you never take out, there has to be a tiny bit of tolerance. Most people are lucky and get very minimal wobble, others wind up with a touch more clearance and see a bit more.

It's worth noting. though, that the worst fit I've ever personally seen, was still notably better than almost any twist-lock barrel.

Doc.

[Dirklax39]

DocsMachine

Any idea why this phantom I just bought has a milled hammer? If it's an upgrade mod, how can I utilize the lighter hammer best?

Thanks!