Some Ideas for Ease of Use

[jbolt]

Jay - you raise a good point about the chemical differences of tap water. I use Rustlick 5050 mixed at 30:1 and haven't experienced any issues with rust. Removed my vise earlier this week that has been on the table for three or four months. No rust and only minor discolorization on the table. Must be the northern Cal water!

I use Kool-Mist in my Fog Buster and rust is a problem. Removing the vise and wiping down the table with oil is what I do. A real pain.

Tom S.

Our water comes from various sources so you never now what the makeup is. I ran the Rustlick as high as 5:1 and still had problems. Also left the machine sticky.

The Koolrite 2290 is mixed at 7.5:1 per manufacturer. They give no ranges just 7.5:1 for everything. Drys super fast with little residue.

Why not use the Rustlick in the fog Buster?

 

[MontanaAardvark]

I find that wiping everything down with FluidFilm before installing a vise or whatever seems to help. I have wicked condensation problems in my garage from time to time, and have spent 2-3 weekends with greenie-weenies getting all my lathe chucks and collets un-funked.

I'm using flood coolant at a pretty high concentration in the mill so I haven't seen any rust inside since I started using fluid film once in a while.

You can get threadmills down to #2; they look like expensive little needles with an itty-bitty head. Frankly, I'd rather trust a threadmill that small than a tap. http://www.lakeshorecarbide.com/singleprofileuncoatedthreadmills.aspx

-S

I'm a boater - in saltwater - so I have some corrosion sprays and things around the house, I just didn't use any because I didn't think I needed it. I thought the coolant had anti-corrosion additives in it.

The FluidFilm says it's lanolin-based, so compared to something like WD-40, I'd guess it's a thicker, waxy film. That's like LPS3, but I just checked and don't see any. I know I used to have a can, so I must have used it up. I have some CRC Marine 6-26, which is more like WD-40 but a bit thicker and won't destroy electrical insulators. (I had WD-40 eat through spark plug wires on an outboard years ago). CRC 6-26 is really popular for boats, trailers, RVs and such, but I've never thought of trying it for this.

Lanolin? I could rub the vise with a Chap Stick.

 

[TomS]

Our water comes from various sources so you never now what the makeup is. I ran the Rustlick as high as 5:1 and still had problems. Also left the machine sticky.

The Koolrite 2290 is mixed at 7.5:1 per manufacturer. They give no ranges just 7.5:1 for everything. Drys super fast with little residue.

Why not use the Rustlick in the fog Buster?

My fog buster is on the manual mill and I use it very little. Just haven't got around to changing it out.

Tom S.

 

[spumco]

I'm a boater - in saltwater - so I have some corrosion sprays and things around the house, I just didn't use any because I didn't think I needed it. I thought the coolant had anti-corrosion additives in it.

The FluidFilm says it's lanolin-based, so compared to something like WD-40, I'd guess it's a thicker, waxy film. That's like LPS3, but I just checked and don't see any. I know I used to have a can, so I must have used it up. I have some CRC Marine 6-26, which is more like WD-40 but a bit thicker and won't destroy electrical insulators. (I had WD-40 eat through spark plug wires on an outboard years ago). CRC 6-26 is really popular for boats, trailers, RVs and such, but I've never thought of trying it for this.

Lanolin? I could rub the vise with a Chap Stick.

Fluid film is more like soupy sour cream in viscosity. It doesn't dry like a wax. Just wipe/brush or spray some on and smear it around. Smells like sheep, which might be a bonus for some folks. It wets out nicely and the capillary action is pretty helpful around screw heads and similar crevices. Set your slimy rag aside when you're done and use it again from time to time to wipe everything down. I suspect it may be like like other oils and if you have a pile of them then keep them in a fireproof steel rag bin if they're really juicy.

Crevice corrosion is the killer on these machines. Anywhere you get oxygen exclusion you'll get a corrosion cell forming - especially if there's a helpful electrolyte like water or coolant.

Same thing for galvanic corrosion - that's why I mentioned using stand-offs on the aluminum fixture plate you were talking about earlier. If you don't paint or anodize it and just bolt it to the iron table, you'll be very, very sorry if you leave it there for a while if you're using a water-based coolant or mister. Fluid film and other barrier films/oils aren't as effective as an actual electrical insulator (aluminum oxide) against galvanic corrosion when the two materials are very far apart on the galvanic chart.

And unlike the zincs anodes in your boat, the iron will become the anode and your table will pit badly.

 

[MontanaAardvark]

Fluid film is more like soupy sour cream in viscosity. It doesn't dry like a wax. Just wipe/brush or spray some on and smear it around. Smells like sheep, which might be a bonus for some folks. It wets out nicely and the capillary action is pretty helpful around screw heads and similar crevices. Set your slimy rag aside when you're done and use it again from time to time to wipe everything down. I suspect it may be like like other oils and if you have a pile of them then keep them in a fireproof steel rag bin if they're really juicy.

Crevice corrosion is the killer on these machines. Anywhere you get oxygen exclusion you'll get a corrosion cell forming - especially if there's a helpful electrolyte like water or coolant.

Same thing for galvanic corrosion - that's why I mentioned using stand-offs on the aluminum fixture plate you were talking about earlier. If you don't paint or anodize it and just bolt it to the iron table, you'll be very, very sorry if you leave it there for a while if you're using a water-based coolant or mister. Fluid film and other barrier films/oils aren't as effective as an actual electrical insulator (aluminum oxide) against galvanic corrosion when the two materials are very far apart on the galvanic chart.

And unlike the zincs anodes in your boat, the iron will become the anode and your table will pit badly.

Thanks for that. I have the aluminum plate mounted to the table now, and overnight. The fog was never on, so it should be safe. I was getting ready to make a test cut on aluminum with a different hold down method, but after working on setting up to do it yesterday, I'm having second thoughts now.

I'm making a GB-22, a single shot 22 pistol that Mark Serbu posted to YouTube several months ago. The frame is a 3/16" steel plate, and I'm going to hold the work down on the tooling plate with the two 10-32 screws in the grip. I'm not sure if this is going to work, so I'm going to take a practice cut in a piece of aluminum. It's only a 1/16" aluminum plate, so I can't really emulate cutting the whole thing and I'm having misgivings about trying it already. Much of the cut is right near those two screws, but there's a cutout up where the 1/16 piece sticks over the end of the tooling plate. I can visualize the 1/16" piece bending down with nothing to support it. I'm afraid this cut might end up meaning nothing.

If I make that cut, the Fogbuster will be on, so I'll take the big aluminum plate off the mill after that.



Bob

 

[MontanaAardvark]

The test cut was uneventful. At some point, I told myself, "this is a test piece - it doesn't matter if you add some more holes". So I put in two new holes and used 1/8" spring pins to hold everything together, along with the three other screws that were already there.



I think it's time to move on to the real, steel work piece. I'm not sure if I'm going to use the same tool plate, but I took it off the mill and wiped everything down with some oil.

 

[Groundhog]

I've used Trim C-350 coolant/lube in my cnc mill for years. When I lived in Idaho I just mixed it with tap water and did not have rust problems. Moved to Kansas and had immediate rust with tap water. Switch to distilled water (@ $1 a gallon) to mix with my C-350 and no more rust problems.

 

[MontanaAardvark]

I've used Trim C-350 coolant/lube in my cnc mill for years. When I lived in Idaho I just mixed it with tap water and did not have rust problems. Moved to Kansas and had immediate rust with tap water. Switch to distilled water (@ $1 a gallon) to mix with my C-350 and no more rust problems.

That's a cheap experiment, which is my favorite kind. I'll try that. I'm still on my first quart, so I think a gallon will last a while.

 

[spumco]

When I wrote that you might get galvanic corrosion, I didn't mean overnight. I meant leaving it on for weeks or months without any sort of insulator or barrier.

If the steel is less friendly than the aluminum, maybe a really sharp HSS endmill would be better than carbide. Lower tool pressure would be a good thing here. Something else could be to add some back-up blocks to the sides opposite the cuts. Run the profile in two operations and remove the blocks when they're in the way. Some mitee-bite clamps (or similar) would be pretty cool here to act as a stop if the screws start to flex from tool pressure.

Another thing... once you have the steel main receiver/grip OD profiled, you could cut a matching profile in the aluminum plate about .125 deep and recess the frame in it to keep it from moving around. I foresee some chatter when you cut that long trigger spring section if the trigger/spring isn't held down with a little top clamp or something. It'll vibrate like a tuning fork. If it's not already in the $12 instructions, I'd suggest cutting the trigger free from the frame (at the front) as the very last operation. Same thing for the frame cut-out for the barrel assembly.

Finally, is there some reason you can't up-size the 10-32 screws? they don't ride on anything and it looks like you've got room for some 1/4-28's or even 5/16" screws to hold the slide sections together. You could even use shoulder screws and ream the holes to get rid of any slop while you're holding them to the fixture plate. If it were me, I'd make them out of thicker stock, hold them in the vise on tall parallels for the profile and top features, and then flip & face and do the back side spring groove. No fixture plate needed for the slide sections.

If you're going to make more than one, mill some soft jaws for the slide sections and bang out 5 or 10 of each component in no time - no having to re-indicate between each section.

As for the GB-22... this looks like an open bolt action. For a single shot, won't the bolt sliding forward bugger the accuracy? And what is the barrel/liner?

Please tell me you're going to thread the barrel and put a can on it. That'd be a sweet little rat gun.

 

[MontanaAardvark]

I understand the galvanic corrosion. I've had a couple of aluminum boats and had to learn about that (some of it the hard way).

There's a lot in your comments. The barrel is a rifled barrel that I got from an eBay seller, but not threaded for a can. I've never gone down that road, and don't think I will here. My plan is to finish this prototype and then build a nice looking one for my wife. The GB-22's designer came up with a closed bolt version that's cooler - there's a video on YouTube. Everyone is hoping he updates the plans, or offers them. I'm on the mailing list and haven't heard anything. If those plans come out sometime soon, I'm thinking I may end up building two of those, if I can't just modify the first two.

I've always planned to cut that slot (3/32) between the trigger and rest of the frame last. I have another large chunk of the aluminum (tooling plate) that is wider than my table and will allow me to put 1/8" pins in all four of the holes where the barrel goes. I think that will keep that area from moving. Those spring pins had to be hammered in and pulled out with Vise Grips, a fulcrum, and the same hammer. Making the holes for the grip screws bigger seems possible, and with no penalty. I need to look at what hardware I have.

Right now, I have three CAM files: a rough cut that you can see the results of above. That's just one pass, because the Al plate is thinner than the steel is. I have a fine cut file that uses a 1/4" EM and cuts the main shapes to size. And I figured I'd follow that with the trigger cut file, using a 1/8" EM. It cuts around the trigger and that long slot to the left. The last operation is to cut the 3/32 channel between the trigger and the rest of the frame. Perhaps I should cut the 1/8" EM file first, since everything will be completely supported in that area while cutting.


Bob