Jump to content


Most Liked Content


#9389 What's wrong with my thinking?

Posted by Sparky_NY on 09 January 2020 - 02:31 PM

I will follow your instructions.

 

It is not obvious to a newbie  that such experienced techniques are so critical. 

 

If I understand your comments, I drill the hole and then ream prior to  proceeding to the next hole (no movement of the work). It appears that a relatively short length reamer will be required to preclude  large movement  on the Z axis. My DRO is one of the Chinese version that displays position to 5 decimal places so the hole location should be accurately placed.

Not reamed, bored with a boring head.   A reamer will still follow a drilled hole that is not true.    A boring head will true up any walking off center the drill bit did which is pretty much guaranteed to happen with deep hole drilling like this.

 

In general terms,  when holes need to be very accurately sized and exactly on location,  boring is the accepted method.   Drilling a starter hole to get most of the meat out is how to start of course,  just leave enough material for the boring bar to true things up.

 

I went through the same problems you are experiencing.    If I recall correctly, Cutter is the one that suggested boring the holes as the best method.    He was absolutely correct !   The hole positions were orders of magnitude improved.

 

Making the bolt carrier in 2 pieces also helps a lot,   the depth of the holes are much less than one piece.   Although its 2 parts instead of one, its actually easier that way with better results.


  • bruski, Roller, Cutter and 2 others like this


#9292 RG-G food for thought

Posted by barrelguy on 10 November 2019 - 05:15 PM

I am a machinist with 60 years experience in the trade who started a couple of guns 3 years ago.  With my machining experience I decided I didn't like the idea 

of silver soldering or welding these parts together.  I used dowel pins and screws instead.  I have disasembled these guns at least 100 times in the last three years

to re-work, modify, tweak, or re-engineer the parts to make the gun work.  I couldn't have done that with a soldered up gun.

     Just food for thought.


  • Sparky_NY, Roller, Cutter and 2 others like this


#9609 Non Elegant solution

Posted by Cutter on 24 May 2020 - 02:57 PM

10-4

 

Mr X

Attached Files

  • Attached File  Mr X.png   402.38KB   0 downloads

  • bruski, Roller, Larryx and 1 other like this


#9581 Server issue

Posted by drhardin on 20 May 2020 - 03:08 PM

Thanks for all you do.


  • Dave, Sparky_NY, Roller and 1 other like this


#9576 Carrier block counter bore

Posted by Cutter on 19 May 2020 - 10:46 PM

With the two piece carrier. I would have to buy another piece of brass, I can only get 1/2 the carrier out of the new piece that I have ready to go. Plus I have to buy an additional hex bushing part for the extra 2 press fit sockets. The counterbore I was using was a 3 flute 27/64 .4219 (within tolerance) but bored a .434 hole, opps your fired! Curious why would an endmill produce a better hole? How would a shop do this with strict adherence to the print without f-up? I was a machinist 40 years ago with some schooling, and only 2 yrs experience. At that time all the work went to Japan, and shops wanted 5-10 yrs experience, they could get it easily. So I went another direction, but I kept my tools. I knew I'd finally get back to it.

 

 

Drilling removes material , Boring straightens the hole, Reaming is for size.
This process is a standard machine shop practice.
Normally a counter bore is made for shallow depths. The counter bore will
follow the hole , so if the deep hole is not straight the uneven pressure will cause
the oversize condition. 
A boring bar or Swarfmonger’s method is best.

  • bruski, gbull, 20Gun and 1 other like this


#9504 Lockdown

Posted by Cutter on 26 March 2020 - 06:34 PM

My wife says gardening is good for stress

Attached Files


  • bruski, Sparky_NY, Roller and 1 other like this


#9432 Semi m60 build

Posted by Dave on 01 February 2020 - 07:00 PM

More pics

 

 

 

 

Attached Files


  • bruski, Sparky_NY, Roller and 1 other like this


#9420 What's wrong with my thinking?

Posted by Larryx on 29 January 2020 - 12:11 AM

I will use the steel bar. It is drill rod from the drops of a company that makes of all things, drills. 


  • bruski, Sparky_NY, Roller and 1 other like this


#9264 Chris’ build.

Posted by maccrazy2 on 12 October 2019 - 10:02 PM

Ok. I got these all sorted out. I made 3 of them so far. The last one came out better than the first two. I ended up using a 3/8 endmill instead of a boring bar to finish out the holes and was much happier with the surface finish. I’m going to remake the first 2 so they all have the same barrel tennon size.
I started with.400 and it’s fine but the material is quite thin between the counterbore holes for the barrel mounting holes. I tried.385 on the second and the material between the holes was more stable but I got a little bit of chatter when boring the holes. Both of them displaced a lot of metal at the surface when drilling the holes requiring more deburring than I expected. I drilled pilot holes and finished with endmills on last one and it came out much better.
In retrospect, I should of made these first so the holes would be fully supported going into the aluminum fixture holding the part. I made the bolt carriers first so the holes are .420 and it caused a burr I had to remove on the barrel plate in all the barrel holes. Not a big deal but one more step that could of been avoided.

Attached Files


  • Dave, bruski, Sparky_NY and 1 other like this


#9258 FInding pictures

Posted by Cutter on 03 October 2019 - 12:24 AM

This is what I did.
The adapter sets on top the frame with a hinge
on the left side and a latch on the right

Attached Files


  • bruski, Sparky_NY, Roller and 1 other like this


#9113 Entertainment!

Posted by Cutter on 23 June 2019 - 03:16 PM

Machinist life

Attached Files


  • bruski, Sparky_NY, Roller and 1 other like this


#9077 New Bolts

Posted by Cutter on 12 June 2019 - 10:17 PM

Cam is in and functioning.
I’ll try popping a blank tomorrow. 
 

  • bruski, Sparky_NY, Roller and 1 other like this


#9058 New Bolts

Posted by Cutter on 01 June 2019 - 05:46 PM

Working on the frame today.
I decided on direct drive for the model

Attached Files

  • Attached File  002.JPG   183.27KB   0 downloads
  • Attached File  005.JPG   174.21KB   0 downloads

  • bruski, Sparky_NY, Roller and 1 other like this


#8989 1 piece Items

Posted by maccrazy2 on 04 May 2019 - 02:30 AM

Nice. I have to let you know the reason I am taking the plunge and starting on this project is the info and photos you and a couple other guys have shared. I greatly appreciate all your help. The modifications and methods you have done really make a working gun attainable. After buying the plans and reading the old forum posts I was deterred because of all the posts where people followed the plans and the guns were quite unreliable.
A big thanks to Cutter!
  • bruski, Roller, Cutter and 1 other like this


#8779 Small surface grinder

Posted by Dave on 05 February 2019 - 11:12 PM

I added a Enco 6 by 12 surface grinder to my shop. I sure wish I would have done this (cheap) addition way sooner. I was told it had only a few hours on it. I took a few pieces off to clean it, looked good on the bottom sides!  It sure makes a neat finish on parts! I can think of a lot of uses for this machine. Came with the magnetic chuck too

 

Last pic is just a test part, before I got the diamond dresser for the wheel.

Attached Files


  • bruski, Sparky_NY, Roller and 1 other like this


#8717 Faux Brass

Posted by Sparky_NY on 11 January 2019 - 01:05 AM

Not machining but material related.   

 

As we all know, brass costs have gotten totally out of hand.    I have been considering alternatives that would look like brass.   

 

About a month ago, I bought a Harbor Freight powder coating system, $60 with coupon.   My main idea was to powdercoat the metal pieces of the tripod when the time comes, probably in black.      Well,  I got to looking and there are 6500 colors/types available from just one vendor (prismatic powders).    They have a "tinted" clearcoat brass that is intended to go either over a chrome color base OR bare polished metal.   I ordered some and today gave it a try.

 

I took a scrap of aluminum about 1x4 , polished it up and coated it.   After the usual baking at 400 deg I was amazed at how much it looks like brass.   How close does it look??????    The aluminum coated piece laid up against my real brass housing matches about as identical as you could ask for !!   Its amazing !!    I would say that with real and a coated piece on the table in front of you, standing, you couldn't tell which is which.

 

I am inside now but will try and get some pics tomorrow.   Don't know how well pics will do justice to such comparisions but will give it a try.

 

Here is a link to the product.       https://www.prismati...ASABEgLKe_D_BwE

 

AND a couple pictures from their website that I would say is a real good representation.

Attached Files


  • bruski, Roller, Cutter and 1 other like this


#8682 Birthday

Posted by Cutter on 04 January 2019 - 07:09 PM

Happy Birthday Roller/Frank !
 

  • Dave, bruski, Sparky_NY and 1 other like this


#8589 .38/.357 prototype

Posted by Sparky_NY on 15 December 2018 - 05:31 PM

AND.... because we like videos.....

 

Have not made crank yet.      SO.....    wanted to run things a bit.        A few more parts remaining but not much.      Notice the redneck test stand !    LOL

 

 


  • Dave, bruski, Roller and 1 other like this


#8414 I made my first part

Posted by Sparky_NY on 27 October 2018 - 12:43 AM

Here is a Fusion 360 rendering of my gun from my cad drawings.      

Attached Files


  • Dave, bruski, Roller and 1 other like this


#7795 D&E Carriage

Posted by Roller on 28 August 2017 - 10:59 PM

Attached File  IMG_20170727_085606.jpg   295.38KB   4 downloadsupdate on project.


  • bruski, Sparky_NY, Cutter and 2 others like this