You seemed to enjoy the barrel clamp post. It occured to me today, as I was working ... that tons of things would not really be obvious to someone who doesn't do this sort of work. Maybe I can stay alert for things along this line.

For instance: You need to put a 1/4" (quarter inch) shaft thru a trigger block. How do you do that?

You might think of using a drill press to keep it straight, but did you think that the part should be clamped into a very sturdy vise? To avoid chatter and movement. Can't get any decent results if the work being machined can move. And, in order to line it up - you really need a two axis (this is two axis with a rotary feature too) ... you need an adjustable table under your vise. So you can dial in the exact alignment of the bit and hole location.

And, after that ... you make sure you have the machine set at the proper speed (too slow or fast and the drill will bind up with chips and fuse the bits to the aluminum part). And ... after you got the lubricant to keep the bits cool and keep the chip binding to a minimum .. then you'd make sure your drill bits were sharp. Won't get anything but a mess with dull bits.

Now ... you figured you'd need to center punch the center of the proposed hole. Then what?



Then, you'd need ALL of these five tools to make that one hole correctly.

WHAT???

That's right. You can't just drill the size hole you want to end up with. You have to start a center drill. Then follow with a size which will track straight and open up the center of the hole. Then you enlarge the hole. Then you enlarge it again ...

Finally you drill with a 1/4" drill bit ... right?

No. You NEVER use a 1/4" drill bit.

Huh ...

No. You can't put a 1/4" ground steel pin in a 1/4" hole.

No?

No. They are the same size. Won't fit. What you need is to go a few thousandths of an inch oversize for the bore. But ... if you drill with a 1/4" drill bit ... it will most likely not make a perfect hole ... and by the time you ream it ... it will then be too big and sloppy. What you have to do is drill the last hole with a drill bit that is several thousandths of an inch under 1/4". That would be a letter sized drill. A "D" drill to be exact. And then, you follow with a .253" reamer, to make the perfect hole for your 1/4" ground steel shaft.

And ... you have to do all of this by instinct ... without a bunch of labor and thought ... or you'll end up with a fifty dollar hole (that you bought ... ... nobody else will pay for it). The five tools have to be available (as well as the center punch and small hammer - or a spring punch). You have to have the stuff laying there while you work (and the chuck key - 'cause you will be changing the bits five times).

And .... that's one hole. Yeah!!!

Gary

Wow,

Precision and beauty all in one package. Can't have to many Barnes guns. I can't drill a decent hole in a 2x4. Dory



Edited 1 time(s). Last edit at 07/28/2009 09:56PM by Dory.

Will a cross slide vice work? Then its off to get more drills and, I suppose a reamer set....just not from harbor freight......

So these D drill bits are specifically sized for this type of work?

So much to learn, and that explains a lot......

Thanx Gary!

Hi Dan,

A cross slide vise is made for this concept - yes. However; most I've seen are not too precise, and not very heavy. You can never have too heavy a vice. You need stability for good work.

The size "D" is just a single drill. A,B,C,D .... etc. They are called "letter" drills. There are fractional drills, letter drills, and number drills. All have a seperate scale of sizes. Charts will tell you what the decimal size of each is. Tip: train yourself to remember the decimal sizes. I.E. .... 3/16" is .187 of an inch. 1/4" is .250. That's the universal number and what you use when you are machining.

Actually - I've gotten some good stuff from Harbor Freight. It's really hard to know. For instance .... they have sets of "T" handle hex wrenches. The set is only 6 or 9 bucks or something silly. And - they are really good steel and really well heat treated. I've bought several sets - all good. I've bought many other kinds that were soft, heavy, awkward, or any number of gbad things. The inexpensive Harbor Freight sets were the best.

You will just want to buy "decimal reamers" in the size you'll need for what - one at a time. No point in buying a "set" - it would cost a fortune and you'd never use most of them.



Gary

barnespneumatic Wrote:
-------------------------------------------------------
There are
> fractional drills, letter drills, and number
> drills. All have a seperate scale of sizes.

So each has it "own" size and increment scale? Ooooo can see where that would be handy. have been frustrated more than once that my bits are just that much too big, or small from any bit I have.

>That's the universal number and what you use when you are machining.
Funy, I had run itnot that just last week end, but your explaination made much better sense. the caliper measure in decimal but the bits are labelled in fractions. Who that that was a good idea? (thats where metric would be so much easier to work with. Their fractions make sense, and you can do them in yer head)


> Actually - I've gotten some good stuff from Harbor
> Freight.
Me too, from the truck sales. The smaller tools seem to be of decent quality, but I'll never buy another drill press from them.......

Dan,

This is the vise I bought. It has gibbs to keep it tight and it's pretty solid and heavy but still managable for a home that doesn't have a dedicated shop.
[grizzly.com]

What is real clear here is that an idea and some stock is not enough to get you to a custom gun!

I'll share a little story here because it is so on topic... Get comfortable.

When Gary made the Prairie III for me he was under a bit of a time crunch. I know that sounds crazy but it's true! We we're headed to a shoot in a short time and on top of that, I came to take delivery and participate in the initial testing (no pressure there). Well, the gun was fantastic and the initial testing showed that it was deadly accurate with several slugs and exceedingly powerful. We had a good test shoot and not much later the second outing was at the shoot. The P3 did well and shot the best 50 yard group of the competition despite not really having had a full evaluation of all the available slugs and power combinations.

After some more shooting it became apparent that the operator (me) was the limiting factor in long range accuracy. It is one thing to shoot a 150+ FPE gun at 100+ yards and quite another to shoot a 270+ FPE gun at 150+ yards. Shooting off of bags that deform as the day or even minutes go by and trying to get consistent were incompatible. I needed some help.

This led to the idea of the Boyenga crutch, the bi-pod! If I could get the variable front bag out of the equation, I might do the gun justice. So, what bi-pod and how to attach it?

Well, the bi-pod decision was pretty easy (a Harris non-swiveling unit) but then came the mount. You can't just strap one of these things on you know!

A custom mount was called for. It would have to match the gun and the bi-pod and it could not take forever to make as once again time was short and shooting needed to get done! With me providing the occasional consent and "that sounds like a great idea" encouragement, Gary came up with an idea known only to him.


The gun with the completed mount installed.

A couple minutes later a huge chunk of aluminum appears from some corner of the shop. The "chunk" needs to be cut to size which is operation 1 of many. Then it needs to be made cylindrical. Of course the cylinder must be of the right size to accomodate all the design features which have been drawn up in Gary's imagination and a simple drawing. Once a simple cylinder of aluminum exists, the hard part starts. A hole must be bored so that the cylinder will fit over the air tube. Note in the pictures that the hole is not in the center of the cylinder. The bi-pod mount has to fit between the barrel and the air tube and has to have enough material to provide a space for the bi-pod clamp to engage. That means the hole has to be drilled off center. Well, it turns out you can't just stand the thing on end in a drill press and get the hole you want. No, you have to change the lathe to a 4 jaw chuck and spin the cylinder on an offset axis and use a bunch of bits and cutters etc. to get a smooth hole bored in the right place. Then you have to split the cylinder so it can be clamped and bore the holes for the clamping screws and machine the flat for the bi-pod clamp and bore a hole for the stainless bushing, make a stainless bushing, and press fit the bushing and chamfer the mount and apply a finish texture, and, and, and!


All that work for just one piece.

Close up for ya.



-- Jim

Jim, I think Ive seen that pic before....

and if you hadnt told me it was an "add on", I'd have never known.

AND ... there's another couple of lessons here ...

For one ... when you design and make something ... on the fly .... you usually find one or two "issues" to deal with. The idea of splitting the pc, and putting the row of machine screws in that area .... and choosing that exact placement ....

caused an error ...

As anyone can see in the bigger than life 47 meg, high def. picture which has now been posted 9 times ... .... the counter bore was too close to the edge, and tore thru. THIS was the reason that I wanted to toss this bracket ... and make a new one immediately. However; Jerry didn't want me to take any more time on it (for my sake) ... and we were going to go shooting ...

But ... the bracket has worked very well ... and has become THE feature of the gun to get the most press. So - the lessons? NEVER allow a customer to say ... "No, no, no .... it's fine ... really .... don't take any more time on it ....", and second .... NEVER allow people to take pictures of said item. It will appear over and over and over again ... for the rest of your life.

Story:

About 2o+ years ago, I used to have a customer who worked for the phone company, drop by in the morning ... and we'd go to breakfast. He also enjoyed a good breakfast - and we'd talk - it was a nice time. Well, the guy wasn't rich (horrors) ... so he'd home in on every darned shop knife I'd make for myself to use in the shop. They were little ideas I had ... made very simply ... from simple materials. He'd nag me, until I'd sell him the thing for a few bucks. Swearing on a stack of Bibles (which I keep in the shop for just this purpose) .... that he'd NEVER resell the knives ... but would just enjoy them as his little collection of my shop knives.

Well, it always bothered me that I was a Master Bladesmith ... but didn't carry a damascus forged steel blade myself! I couldn't afford it!! However; one day, I ran across a little pc. of damascus steel ... that had a flaw in it. I thought to myself .... I could make myself a folder out of that little strip of steel. The flaw was small, and wouldn't effect the usage - and I'd have a good blade to use. And ... I'd never sell it because it was flawed. In fact ... I even acid etched on the tang "Scrap Damascus - Not For Sale", in very small letters.

So; you know where this is going. The "Breakfast Guy" began nagging me, relentlessly, over this little knife. It went on and on forever. Finally .... it had it's effect. I sold the guy the pocket knife. The sight of this big guy crying and blubbering and whining just became too much. Well, the guy swore on all that's sacred .... he'd NEVER sell the knife. Just wanted the knife to be the crown of his little shop knife collection. Besides, the guy was getting married very soon. I figured he needed a break. haha.

Well, I was working on my display knives for the New York Custom Knife show. I had a group of marvelous knives for the show. I was real pleased with them. I was talking to one of the biggest collector/retailers of custom knives a week later at the show. As I talked, I just scanned his cases of knives for sale. And stopped. There was the damascus steel shop knife ... with an $1,100 price tag on it. WHAT!!???!!!??? The guy must have driven from my house to the dealer's house!!!! Within a week, the knife was in New York ... as a prime example of Barnes Knives!!! haha. AND ... that whole collection of little cheap shop knives has been appearing, over and over .... year after year .... as some collector buys an inexpensive BARNES custom knife ... and then contacts me to find out what his treasure is worth.

Now ... the only part that has to do with this thread ... is to remind myself to immediately CRUSH anything that's remotely flawed. Because it will turn up more often than my best work. haha.

Jerry liked his bracket. It was made so we could go shooting. But ... I'm beginning to think it's gonna take a monthly check, under the table, ... for him the STOP showing it. And ... Jim's a BIG help ... "Here's an X-Ray scan of the device ...." ... I can go bigger if you like ...!!!



Gary



Edited 2 time(s). Last edit at 07/29/2009 04:39PM by barnespneumatic.

Funny . . . I never even noticed the flaw until you brought it to my attention.

Lemme see if I can find the ultra zoomed-in view of only that counterbore that takes up the whole screen . . .

I saw it! I saw it!

I didn't dare say anything though.

And Lon,

THAT's the reason I had to post on this part. NOT to "Ping" Jerry .... but because everyone who saw the pics (except Dan ... ) probably said ... "so THIS is what people are waiting for??!!!" Can't let that stand. Jerry was being nice ... not trying to do an axe job ... I think ....

Gary

Well Jeez o' Pete did I start the wrong thing! I thought I was pointing out the 87 steps required to make something that is supposedly simple and the whole thing turns into a comment on a flaw that is entirely cosmetic in effect and due to the time constraints artificially placed on the fabrication. For what it is worth, that mount went from concept to installed in a couple hours while I was pretty much watching, holding a chuck key to pretend I was useful, staring at my watch and tapping my foot!

The mount fits the air tube so perfectly that it is rock solid with just finger pressure to tighten down the screws. Every one of those screw holes could have been slotted to match the flaw and the mount would still hold just fine. The mount is as solid as the door on many gun safes... The mount does match the rifle. It is my gun and I asked for that finish. To my eye it looks purposeful and provides a nice contrast where a black finish would have looked like a weight and anodizing to match would have been a stylistic overkill. I ruled out a mirror finish for the same reason. Disagree if you wish but the finish is my choice. That mount has no chance of coming off the gun. I've put thousands of rounds downrange and I've grown very fond of the mount and bi-pod!

couple of hours.

"So if Gary ever let's me visit him, I can have one put on my guns, Just sit and wait. I've waited in Doctors office longer than that. Sorry about that Doctors.

Gary I couldn't resist. Ha Ha Dory

Gary I'd have never seen the spot where it broke thru, if yo hadnt mentioned it..... but now that you did, I see it, but I still had to look....


Did you polish the hex heads or is that a stainless screw? Either way, that kinda detail is awesome.

Is that why the space is wider on that end? You didn't want to break it out. Guess you'll have to borrow it sometime and make a new one. Guess you could always wrap some baling wire around it if it looks like its cracking. Dory

Thank you Dory. The bailing wire is something that didn't immediately come to mind. However; I think it's a good solution.

Gary

There's been a lot of jokes, over the years made about baling wire. Of course now, it's duct tape. But on my Grandfather's farm you would find it, in the weirdest places, still doing it's quick fix job years later.

Of course, I'm surprised, also, Jerry hasn't given it back to you to be anodized, to match the rest of the gun.Dory

Dory Wrote:
-------------------------------------------------------

> Of course, I'm surprised, also, Jerry hasn't given
> it back to you to be anodized, to match the rest
> of the gun.

I was wondering that too......

Hehehe....I hadn't spotted the glitch until Gary pointed it out!
Gary the perfectionist strikes again
Mind you, his customers will be thanking him for that particular trait.

Well, haven't we opened the flood gate now? haha. A bit of a gap is there? NOT anodized you say? "I didn't WANT to mention it ... but ..."

Why ..., ... why ... it's almost as if it were made, while the truck was idling in the driveway, in order to see if the gun would take well to a bi-pod that very afternoon!

Didn't notice it???? Well ... Dan ... you'd sure be an ideal client for any artist. haha.

That's the point. Of ALL the detail, on all the guns ... this post was made to offer sincere appreciation of that part. AND ... in a thread where I've gotten more kudos for doing the absolute most simplistic operations of my career.



Gary

Just slap a gob of JB Weld over it and file it down flat after it dries. A shot or two of Krylon and you're good to go.

Actually, it probably would have worked just fine with two screws and roughed out of bar stock with a hack saw. If it were me I'd have just center-drilled a chunk right down the middle and ground down a flat(ish) spot to clear the barrel with a belt grinder.

Which explains why Gary is making custom airguns for a living and I'm mostly limited to producing firewood out of logs.