Making a new part for a Saeco luber

[KeithB]

Got the soft jaw cut yesterday.There are two cavities, the one on the left holds the piece upright like a regular T, the one on the right holds the piece with the crossbar oriented vertically. The left cavity is used for the third operation on the CNC mill. During this step the crossbar is milled flat to clean up using a 2" face mill, the ends are milled to make a radius, and the guide rod holes and top punch hole are drilled and reamed to size.



Here is a part mounted in the soft jaws. A hard photo to take, this is a shot from inside the machine looking out the access door. My vise has the fixed jaw near the handle, the movable jaw is pulled into the piece.


An edge finder was used to touch off each end of the part to find the center. The edge finder was also used to touch the front of the part so that the offset to the center of the part could be entered. I programmed the piece with X0, Y0 at the center of the top punch hole and Z0 is the finished top of the crossbar.


Here is the part after the crossbar has been clean up milled, the ends radiused, and the holes drilled and reamed.


The part after the third step, ready to get the handle slot cut.


Here is the part held in the right hand cavity of the soft jaws to enable cutting the handle slot.


Here is the finished piece, it needs to be deburred and cleaned up and have some sort of surface treatment applied.


The original part was more triangular shaped, it measured about 1-1/8" wide across the base of the handle slot and about the same distance from the top of the ear to the bottom of the slot. The original part was cut on a horizontal mill using a 1/4" wide circular saw-type cutter. I don't have a horizontal mill and cutting 1-1/8" deep with a 1/4" end mill is pushing things a little. A standard 1/4" end mill will cut a little over 3/4" deep, so I redesigned the part to make it 3/4" across the base of the slot and I turned the piece 90 degrees so a vertical mill with a standard 1/4" end mill could be used. By knowing my tooling and it's limitations I was able to make a minor change to the part that allowed it to be made completely in our shop using existing standard tooling.

 

[Rick]

Fascinating. That is certainly a lot of work, now that you have the CNC all programmed how long should it take run off the parts start to finish? Makes perfect sense that a shop making one of something is more expensive than making 50 of them.

 

[KeithB]

Approximate machine time:
1. Cut the block off in the cutoff saw - 4 min
2. Cut profile on CNC mill - 12 min
3. Mill off one side to 3/4" thick - 12 min
4. Mill, drill holes in crossbar - 8 min
5. Cut handle slot - 3.5" min

Don't know how much time it will take for clean up and surface treatment.

This doesn't include setup time or hand(ling) time. It doesn't take much time at all to set up the cutoff saw but it takes 30 minutes to an hour or more to set up multiple tools in the CNC mill. The time it takes to complete a batch at each step is the sum of the setup time and the total time to run all the parts, which includes machine and hand(ling) time. If you only make one part then the setup time is a significant fraction of the total time to make that batch of one, if you make hundreds of parts then the setup time becomes a less significant fraction of the time to make each piece.

Making good, simple fixtures cuts down hand(ling) time to a minimum. For the last two mill steps I can literally drop the parts in the jaws and they self-align, swapping parts takes about 15 seconds.

 

[smokeywolf]

Nice part Keith. What a lot of people don't see or think about is all the deburring and softening/breaking of edges done typically with countersinks, files, wire wheels and/or Scotch-Brite wheels.

If I had to mill that slot on the Bridgeport and had no right angle attachment for the spindle, I think I'd try to clamp a toolmaker's/grinding vise in a vertical orientation in the Kurt and put a milling cutter on an arbor. Not sure, but I think the Bridgeport's quill would clear the back end of the toolmaker's vise sticking up out of the Kurt.

 

[KeithB]

Luckily I have enough time while the mill is cutting to mostly debur the previous piece. Big burs are taken off with a medium single cut 8" file and a 90 degree countersink tool in a Shaviv handle takes care of chamfering holes. I will hit all the edges with a Cratex wheel in a pencil grinder, and if I have my friend blacken the parts he will bead blast them first.

Yes, deburring/prepping the parts can be a significant part of the time it takes to make something.

 

[smokeywolf]

I will hit all the edges with a Cratex wheel in a pencil grinder

Cratex is incredibly handy and I completely forgot about it.

 

[dromia]

Thank you for this thread. To unskilled and untalented people like myself reading this is a real eye opening pleasure. Even if I don't know what a lot of the words describe.

 

[KeithB]

A lot of people, myself included, enjoy seeing the process of making things. Love the TV show "How It's Made". Look at how popular DIY vids are on Youtube.

Since I am now in the business of making things to sell for my supper I thought I might share the process of making a part from scratch. Sorry, I don't make gun parts but one can imagine similar manufacturing procedures and thought processes involved in making parts for firearms.

I'm out of the perfessoring business but every so often I have to scratch the itch and write something at least a little instructive.

 

[Rick]

That "How it's Made" show kinda drives me nuts. All I can think of watching is hey, you missed about 10 steps there. I learned how to build a complete top of the line Mack tractor in about 3 minutes flat. Start with a chassis, no idea where that chassis came from, it's just kinda there already. Slap on the axles but again no idea where the axles came from. Now bolt in the engine/trans, must have picked that off a tree or something. Here comes a complete fully assembled, painted cab flying in from over head, bolt that down and all that's left is some tires & drive it off. Did you know it only takes three minutes to manufacture a lever action rifle?

The show would have far more appeal for me if they would instead of having 4 different things in a half hour show, half of which is commercials, show one thing and actually show . . . How it's made.

 

[KeithB]

Yeah, they do have to boil it down to the point where sometimes important info is lost.

 

[Rick]

There is far more detail and info in this thread on how it's made than there is in any segment of that show. Maybe why it's more interesting.

 

[Brad]

Best part of "How It's Made" is the things like spring benders and winders. The fact someone figured out how to do those things quickly and efficiently is amazing to me. I also like the machines that orient parts in one direction.

I am less interested in what is being made than I am the machines that actually do the work and the processes involved.

 

[Ian]

I read through with the intent on commenting about the quality of the process description, good to see I'm not the only one impressed. Obviously this was done by a professional instructor. I studied each process description and photo until I understood it, then immediately a question of "OK, got it, but now how did he....." and then scroll to the next photo and it's right there, and so on. One careful read through and I got it.

I'm thinking the narrowed snout matters not because the material strength makes up for the material loss. Also, the end mill leaves a radius at the bottom of the slot. I'm sure there are slitting saws with radius but that's buying more tooling, and would have to make another fixture to hold the part to be slitted in a vertical mill.

Hopefully the person doing the blasting will install a screw in the threaded hole of each part to protect the threads.

 

[KeithB]

Just dropped the parts off with my friend Jeff, owner of Midwest Hydrographics. He will bead blast them and then put an industrial black finish on them. He expects to have them done sometime next week. I know the finish is tough and doesn't appreciably add to the surface so no problems with build up in holes and threads. It also resists rust really well and retains a little oil, just wipe an oily rag over it and you're good to go.

I'll post a picture here of the finished parts and add them to Keith's Korner when they are ready.

Edit to add: Jeff is a real pro, there will be no thread damage done during the bead blasting.

 

[Brad]

Keith, I have a project I need to discuss with you. Look for a PM soon.
I need to see if it is something I can do when I get my mill or if I would be in over my head.

 

[KeithB]

Always glad to talk.

 

[freebullet]

Don't even own a saeco, but this was definitely helpful & worth the read.

 

[Pistolero]

Really nice looking part, Keith. I can see why anyone who starts with your
company will stick with you.

Bill

 

[Pistolero]

Come on, Brad once you get a mill, making that SAA from scratch will be 'pretty
straightforward'.


It can be done, but would take a lot of time.

Bill

 

[RBHarter]

Only the first one ...

 

[Rick]

Just dropped the parts off with my friend Jeff, owner of Midwest Hydrographics. He will bead blast them and then put an industrial black finish on them. He expects to have them done sometime next week.

I'll post a picture here of the finished parts and add them to Keith's Korner when they are ready.

We should expect to see the final photos soon I would think. Curious minds wanna know.