DIY parts

w_houle · December 26, 2008, 02:45 PM

I have been contemplating making a slide for a pistol that I have. The problem is I am not sure if the equipment I have chosen will be up to the task and the sequence of cuts I should make.
I have decided that since this is a small project that it can be done on a drill press.
Then the problem of what sequence of cuts:
I think I should start with the bottom and work up, and from the back forward, but then it comes down to one trapezoid cut (for the trigger disconnect) on the inside of the frame that I have no idea as to how to replicate.
Oh, and for those who seriously want to know more about the particular gun, I can PM the details.

dahermit · December 26, 2008, 05:07 PM

The spindle bearing slop on most drill presses is too great to allow precision machining. I think that you would be more likely to be successful if you were using a vertical milling machine.

**Unclenick** · December 26, 2008, 10:08 PM

Even if it is just an inexpensive Mill/Drill it will be far more successful than a drill press. Remember that a drill press has thrust bearings because all the pressure it is designed to encounter is axial, not lateral. Cutting causes lateral pressure, assuming you have an X-Y table on the press you are using. This is OK for wood and the like, but when you start cutting metal the pressure gets high enough that the short Jacobs tapers used for most drill chucks will loosen and you'll find the spinning chuck and cutter popping off all the time.

As to a cut sequence, you usually identify the major round cuts and make those first. Unless you single-point bore them with a lathe, a round cut not in solid material will tend to walk toward any cutout it encounters along one side. The bigger the hole diameter, the more rigid the cutter, so the problem decreases with size, but you need a multiple-fluted end cutting end mill for best rigidity, even then, and an X-Y table that is either very heavy or has no backlash so it can't wobble under your cutting load. Slots and straight cuts come last except for small holes for pins and screws that don't need to be cut through a lot of extra metal.

Try your design out first on something relatively soft so you can see where the problems are? Wood or plastic are OK to test your skills.

Good luck.

Swampghost · December 26, 2008, 10:41 PM

IHHO this is a very bad idea on any number of levels the best being that you'll end up with something that will not shoot well and possibly hurt you or someone nearby.

I'm a machinist and one company that I worked for made gun parts including the recievers for the AN/GAU-8a 30mm Avenger used on the A-10, the M134 mini-gun, parts for Raven, Colt and others.

The process involves machining specific steels into parts to +/- a minimum of 0.001" (not capable of most drill presses). The part is then heat treated to a specific hardness which also causes some warpage. Critical surfaces, such as slide interfaces, are then ground to spec. depending on final finish which can nothing to a lot.

What steel were you considering starting with?

sadsack · December 27, 2008, 01:43 AM

W: You might consider buying a slide with all the cuts made and fitting it to your frame.

December 26, 2008, 02:45 PM	#1
w_houle Senior Member Join Date: March 29, 2007 Location: Raleigh, NC Posts: 1,391	DIY parts I have been contemplating making a slide for a pistol that I have. The problem is I am not sure if the equipment I have chosen will be up to the task and the sequence of cuts I should make. I have decided that since this is a small project that it can be done on a drill press. Then the problem of what sequence of cuts: I think I should start with the bottom and work up, and from the back forward, but then it comes down to one trapezoid cut (for the trigger disconnect) on the inside of the frame that I have no idea as to how to replicate. Oh, and for those who seriously want to know more about the particular gun, I can PM the details. __________________ How could you have a slogan like "freedom is slavery" when the concept of freedom has been abolished?

December 26, 2008, 10:08 PM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	Even if it is just an inexpensive Mill/Drill it will be far more successful than a drill press. Remember that a drill press has thrust bearings because all the pressure it is designed to encounter is axial, not lateral. Cutting causes lateral pressure, assuming you have an X-Y table on the press you are using. This is OK for wood and the like, but when you start cutting metal the pressure gets high enough that the short Jacobs tapers used for most drill chucks will loosen and you'll find the spinning chuck and cutter popping off all the time. As to a cut sequence, you usually identify the major round cuts and make those first. Unless you single-point bore them with a lathe, a round cut not in solid material will tend to walk toward any cutout it encounters along one side. The bigger the hole diameter, the more rigid the cutter, so the problem decreases with size, but you need a multiple-fluted end cutting end mill for best rigidity, even then, and an X-Y table that is either very heavy or has no backlash so it can't wobble under your cutting load. Slots and straight cuts come last except for small holes for pins and screws that don't need to be cut through a lot of extra metal. Try your design out first on something relatively soft so you can see where the problems are? Wood or plastic are OK to test your skills. Good luck. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

December 26, 2008, 10:41 PM	#4
Swampghost Senior Member Join Date: April 18, 2008 Location: Florida, east coast Posts: 2,106	IHHO this is a very bad idea on any number of levels the best being that you'll end up with something that will not shoot well and possibly hurt you or someone nearby. I'm a machinist and one company that I worked for made gun parts including the recievers for the AN/GAU-8a 30mm Avenger used on the A-10, the M134 mini-gun, parts for Raven, Colt and others. The process involves machining specific steels into parts to +/- a minimum of 0.001" (not capable of most drill presses). The part is then heat treated to a specific hardness which also causes some warpage. Critical surfaces, such as slide interfaces, are then ground to spec. depending on final finish which can nothing to a lot. What steel were you considering starting with? __________________ NRA Patron Member

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December 26, 2008, 05:07 PM	#2
dahermit Senior Member Join Date: October 28, 2006 Location: South Central Michigan...near Posts: 6,501	The spindle bearing slop on most drill presses is too great to allow precision machining. I think that you would be more likely to be successful if you were using a vertical milling machine.

December 27, 2008, 01:43 AM	#5
sadsack Senior Member Join Date: February 4, 2006 Posts: 206	W: You might consider buying a slide with all the cuts made and fitting it to your frame.