I've got a 16mm bar that'll do nicely.. means I can do it all without repositioning the work in the clamp too, as the travel in the mill is only around 70mm, whereas with your approach I could do the whole lathe bed length... can also fine tune the radius with cutter seating depth.
Just need to build a workpiece clamp on the toolpost, but that's not too big a deal... time to dig out the mig...
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
you don't need to use a ball nosed endmill you can just mill slot like a falcon uses
I have a right angle milling adapter that sits atop the slide instead of the toolpost (with about 70mm vertical travel via it's own slide), which has a small machine vice mounted on it, facing the chuck.
I can modify an old crude tool holder to clamp the workpiece, so it can approach horizontally rather than longtitudinally...
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
tp seals in the barrel so it won't make a difference really but if you did it like a falcon it would be a bit more work to get the clearance right
Funny you shoudl post that first one.. the prototype I've just started on will be very similar...
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
So I used this (purists look away now):
To make this, starting with a few passes with a regular end mill, then switching to the round nose. Taking around 0.1mm off for each pass, it was fine.
fits on this:
Now to turn it around, and do the other end. Will probably take me longer setting it up with the DTI than the actual milling, but hey... I'm not going into production on these, that's for sure !
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
OK, flipped it round, and with a lot on fine tuning, got the two grooves to line up...
Fits fine:
It's about 40mm longer than the std plastic one, which seems about right. I can always trim down at the barrel end if needed. It's surprisingly weighty, but these guns are all way too light anyways, so no bad thing
Next is to drill the barrel and bolt holes... offset or co-encentric... will have a measure.
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
coming on
i prefer to bore for the barrel and probe first then i can set the block in the mill using the bore to set it up so the top can be milled flat to the barrel and then once the top is done flip to do the underneath
that was my original plan (to bore first)... but when this test looked like it was going to work I just went with it In the three jaw chuck, I'm thinking to put one jaw down the middle of the groove, offsetting the barrel / probe about 2mm, which will enable me to use a barrel a mill or two larger
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.
I've been busy today too, and went with the boring bar method, used an old 16mm steel bar and center drilled it in the end so it could be stabilized by a live center. Used the milling attachment to hold the breech, and aligned it with the already drilled center holes.
Had to mount the boring bit at two locations on the bar to get the entire track milled out, and adjusted it manually to the same depth. That took some measuring! After a bit of sanding with some 180 grit paper wrapped around a 20mm steel tube it worked out really well
Too many airguns!
Yes, a bar I bought off "3baj". I didnt mill the track as deep as you, hardly deep enough to cover the transfer port. But this is because I want some extra space for larger barrels. But it still sits very nice on the tube, we'll se how it turns out.
Now comes the placing of the holes and the loading port..... I've left a few mm's extra at each end, and will start with milling the loading port and locating the breech mounting screw hole, so I can trim the rear end to length after those critical dimensions are established.
Too many airguns!