XS60C PCP Repeater project

[stalwart]

The second option could be made very pretty. The trigger housing is tall anyway, cutting just enough to properly reveal it... would look pretty hot.

Not asking anyone to quote Norm's work, but roughly how much does a stock like it hurt?

[rsterne]

$210 unfinished, $250 finished.... Boyd's just had a HUGE price increase....

Bob

[QVTom]

$210 unfinished, $250 finished.... Boyd's just had a HUGE price increase....

Bob

Huge increase.  The nice lady who runs Richard's said that a big  manufacturer picked up the burned factory and is now in the process of refurbing the plant.  Pretty sure she meant Boyd's but wouldn't or couldn't be more specific.  Explains the huge increase.

[stalwart]

Just took my first close look at the Disco Double... pondering doubling up a 60. Liked everything I saw, thought I'd see if it was cheap enough to talk me out of trying to make myself one. Took a look at the price...

I am just 1 tap away from mounting those parts to a 60... and I can't build myself one for what he gets for a well finished, complete product. I don't have the time to work for free, even for myself. 

Also looked at Blasters for the first time. I really like the "pepper", but the "coyote" would strike a chord in these parts. If anyone wants to get distinctive, I could color match the actions to the accent colors in the stocks... in high quality powder coating.

I know what I want for my birthday... 

[stalwart]

Anyone know, offhand, how long DD tubes are?

[rsterne]

REVISED:

They are 18.05" long, including the rear plug, measured from the front of the Disco tube.... In addition, the two front plugs (including fill covers) add 1.25" to the length of both tubes at the front.... They will fit any tube with internal 13/16"-28 threads on the front.... It would be worth talking to Norm about an XS-60c version of the Blaster, and a Double tube version of it.... He is doing the stocks for the new Millennium Pumper, so I know he works on stuff other than Crosman....

Coyote?.... Is that a desert Nutmeg?....

Bob

[stalwart]

Yes, stacked with what they call "natural"... 2 very common colors in the summer here.

[rsterne]

Today I started on the reversed tank blocks.... I have two to make for myself, and one for stalwart.... so as this is a run of three units I decided it would be a good thing to keep track of the time.... This does NOT include the hours of design time, prototyping, design changes, etc.etc. which took place while developing this design to fit the 22XX/Disco/QB tubes which it will also fit.... The first step was to cut a length of 3" x 1" 6061-T6 bar stock into three pieces, and then cut those to the appropriate height, using a horizontal metal bandsaw.... Then I squared one edge (the front) to the one remaining untouched side of the original material (the top) using the milling attachment on my lathe.... Then I cut out the material from the notch formed by the tube insert and the back face where the tank will mount, again using the bandsaw.... Here is a photo at this stage....



I admit I'm not very speedy when it comes to machine shop work, I spend too much time measuring and thinking, so that hopefully I don't make any mistakes, and do things in the best order to not cause myself more work later because I worked myself into a corner.... at this point I have a total of 3 hours invested, of which 2.25 hrs. is machine time, the rest measuring and pondering what to do next....

I like the Coyote, didn't see it on their website....

Bob

[stalwart]

I already stock powder in Mil spec "Desert Tan"... If my monitor is accurate, it's a very close match to the "natural" in the stocks. I think it would make a pretty rifle, with serious overtones.

So many shiny objects... so little time...

[rsterne]

Indeed.... and my afternoon was spent making chips and smaller shiny objects out of larger ones....



I mounted the pieces above in the four-jaw chuck in my lathe, and spent quite a while getting the first one in the correct position and centered, so that the tube that slides over the stub will be flush with the top of the block, and centered side to side.... The result is that the stubs are completed, including the O-ring grooves, and the rear of the blocks are faced off flat as well.... As usual, the first one of anything takes twice as long as the next one, and true to form the first one took nearly two hours, but to finish all three "only" took me 3.75 hours.... so the total time now on the three tank blocks is 6 hours (2 hours each)....

I've had enough for today, any more and I'd probably start making mistakes.... More tomorrow....

Bob

[stalwart]

Not only do you deserve a break, Bob... you obviously know the smart times to take them.

Nicely done.

[RMM]

While rsterne and stalwart are off on their mothership fabricating out this world air gun stuff I stayed back on earth awhittlin onna bobcat.

I’m also working on a 1.5K to 2K reverse tanker Bobcat, very slowly, and thought I’d share plus get some ideas on the rear tank attachment I fabricated. 

As you can see in this first pic it appears the tank is just floating in air suspended by the upfront tank reverse adapter but it’s not



I whittled (routed) out the stock to receive a fabricated (bent) and angle made out of.125 x .500 aluminum (6010) with a circular attachment piece (.250 thick, 6010) for the plastic bottle holder (left over part from a vacuum cleaner hose extension kit).  I have a polyethylene glue kit  to  fasten the plastic tube to the circular aluminum so I can dismiss mechanical fasteners.  ( I saved some of polyethylene cuttings to test)







I cut the circular piece with a hole saw then turned it down on a lathe to fit the plastic tube.  I attached the angle to the circle by cutting a keyway to fit then machined a stepped plug to fit in the hole left by the drill bit in hole saw which was drilled and tapped to fasten the angle.   I'm to the point right now I'm not sure if I want counterbore the stock, fab a couple of ferrules for the counter bores, for a couple of flat head SHCS to fasten the drilled and tapped angle to the stock or just plain epoxy the angle to the stock.

As far as the fastening the stock to the receiver I plan on making a new backing block, using a couple of extra flat head SHCS for safety then use the OEM hole as a fastening point for the stock with a ferrule in the stock for the bolt to pass through and to keep from compressing the wood (the ferrule will be compress a flat spot on the backing block). 

I found great pleasure in shooting the stock Bobcat but I'll take greater pleasure in having more time to shoot without multiple refills with the 13ci bottle. 

[stalwart]

Well done!

I knew when I shipped that 'cat, it was going to a good home... 

[rsterne]

Today was the job I hate, because it is soooooooooooo easy to make a mistake and ruin the part, or end up with a leak.... Fortunately, that didn't happen, and I ended up with three usable tank blocks (at least so far) that hold 3000 psi just fine.... You can see the fitting I used to test them.... Here are the parts....



The 1/4" hole at the bottom of the fitting is the air passage, and there will be a 1/8" pin protruding from that to open the pin valve on the regulator.... You have to remove the gauge and Foster from the regulator to rotate it under the stub for the air tube on assembly.... The threads are 1/2"-NPS, and were done in two stages, with a plug tap, run by hand in the lathe as per the photo below, and then finished with a bottoming tap that I had to grind flat from a second plug tap.... This is the setup I use for accurate and square threading, using my lathe....



There is a lot to see in that photo.... On the left is a hand crank, inserted into the hole in the spindle, and secured with a split/tapered nut the same way the seat post on a bicycle works.... You slide it in from the left, and reach inside the spindle with a socket wrench to tighten it in place.... This allows you to turn the chuck by hand, with good leverage.... The tap is in the chuck.... The tank block is clamped in the milling attachment.... It sits against an end stop (against this end of it), back against the vertical part of the milling vice, and clamped down, so that it can be removed and replaced at will and will always go back in the same place, allowing all three parts to be made without altering the vertical (Z) or crossfeed (Y) settings, they are locked in place once the correct location for drilling and tapping the hole is determined.... The carriage moves left and right (X), to drill the holes, and you can see a dial indicator on the ways that tells me how far in I have drilled or tapped.... When tapping, I run the part up against the tap, zero the dial gauge, push the carriage to the left by hand to load the part against the tap, and start cranking the chuck by hand.... Once it gets a good bite, the carriage just follows left and right as the tap screws in and out of the part, and the dial indicator tells me how far in the tap has advanced.... When making these tank blocks you have to be careful not to damage the straight bored portion below the threads.... I finish the job in a bench vice, using the bottoming tap by hand....

Anyway, that's how I made the ASA fittings in the tank blocks, and today was a very successful day.... I did a practice version in a piece of scrap that took an hour, but I didn't count that as part of the time (probably should have).... The total time for drilling and tapping the three blocks, and machining off the bottom of the blocks to the proper depth, was 3 hours.... so the running total is now 9 hours, 3 hours per tank block....

Bob

[RMM]

Bob, I'm following your build with great interest and thank you for the in depth detail you provide. 

[tominMPLS]

Bob, this is another great example of your willingness to share information on your projects.  I especially appreciate the pictures of your machine setup and covering some of the ways you overcome a problem.  That hand crank setup is brilliant!  I have never used a milling vise like you have but would assume that it is not very easy to hold close tolerances with a setup like that.  It sure doesn't look very solid.  I would think that it would invite quite a bit of vibration?

Thanks again!

Tom

[rsterne]

It's not the greatest, but when you don't have a Mill, you don't have any choice.... The vice jaw is only 1" deep x 2.5" wide and opens just over 2", Vertical travel is only 3", and crossfeed is only 6", so all those limit you as well....

That hand crank setup is compliments of Lloyd Sikes, he uses it for single point threading, particularly up against a shoulder.... No more worries about crashing the work, and you can leave the half-nut engaged all the time....

Bob

[rsterne]

You asked about the rigidity of the Milling Attachment above, and I didn't mention one of the major drawbacks.... With the lack of rigidity in the tower, you can only take light cuts.... I usually use 0.020" in aluminum (sometimes 0.030") for roughing, and 0.010" or less when finishing.... That is one of the reasons everything takes me so long.... Today's project was to cut the 3-slot Picatinny Rails in the bottom of the tank blocks.... Here is what they look like now....



The were four major steps involved, and four milling cutters.... First I had to narrow up the rail (5 cuts per side), then cut the undercut (8 cuts per side), then the bevel (4 cuts per side), and lastly the slots (8 cuts per slot).... The total time was 3.75 hrs. for the three blocks, so the total time is now 12.75 hrs. (4.25 per block).... BTW, that works out to 174 passes through the mill, plus deburring and finishing afterwards....

I still have to machine the recess in the top front corner to mount the barrel band and drill and tap the mounts for that, machine the mounts for the three screws to mount it to the tube, drill the air passages, and fit the plug for the air passage in the bottom.... I really enjoy working at this pace, doing a specific job each day, and a run of three isn't too terribly boring.... I can't imagine having to sit down and do ten (or a hundred) of anything anymore, I had enough of that when I was working....

Bob

[RHytonen]

Beautiful work, Bob.

It's encouraging to see there are those who still understand it takes real time to do something right.

Rod

[stalwart]

I'm working on the first 3K Bobcat, and had to show this to you guys. The PRod mags require the shallowest slots, and they don't go through the tube (hence won't require an extended and relieved block to cover the gap), and in fact leave enough steel to make a very stout "dust cover".

The 3k 'cats will use the standard configuration (with backup screws), but will get the recessed trigger guard mounting so you can mess with custom hammer weights without interference.

This will be a simple, clean and cost effective little rifle... with a real sting.