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General shop techniques

AlfaGTA

Diamond
Joined
Dec 13, 2002
Location
Benicia California USA
One of the things i enjoy about this forum is seeing how others solve setup and machining jobs.
Been a bit light here on the board so i thought i would post a few of my solutions to setup problems....

My work often centers on working on existing parts as such you often have to decide on ways to hold the part. Often more difficult than making something new where you get to choose the complete
process and steps involved....Not so with repair work.

Lots of times i need to indicate a feature where the point to check is not easily reached...Just can't get your fingers there to adjust the indicator, much less see the reading.

Here is a setup where i needed to indicate the lower cylinder locating bores down in an engine block....With indicator and mount there just is no room to get my hands in there to set the indicator...

Solution: I use my fine boring head coupled with a long small tool extension.
This extension i have had fro years, not sure where i got it or who made it...But it has been very useful. Tool is 1/2" OD and hollow through. Used "DA" style collets and closure nut...
In this case i am holding the 5/32" stem on my "interapid" indicator....(this is my go to test indicator brand)

Holding the indicator extension in the boring head allows moving it to set zero without needing to get my hands into the hole


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There are times when you need to hole a part that does not have a convent place to clamp it or you need to surface a complete area where clamps on the side would get in the way...
Often parts already have threads and studs that can be in the way..or can be used to advantage.....


Her is one example...Part is a supercharger drive gear case from a type 35 Bugatti......
Need to machine the end of the casting as an assembly, want teh reference and finished surfaces to be parallel.....
Casting has studs....

I make these round hold down pucks as needed...OD large enough to bridge the distance from the stud or thread to the part edge....Generally make these around 1" tall and counter bore the center to
clear a nut or bolt, deep enough to clear the length of the bolt or stud.....

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The puck is placed on the machine table and held down using a normal step block and clamp....
More to follow.......
 
Here are some additional examples using the "puck" hold down ...
Pucks are surface ground in sets...so they are all matched for flat and height....
Here is one mounted on the pan rail of an engine block....

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Here is the overall setup. Clamps applied to the overhang of the puck....Has some advantages.
Pucks give defined points of contact , easily tested to be sure the part is not being twisted or distorted by the clamping ...Also provides defined point for shimming if required.
Further the clamping force is directly through a solid section, clamp directly over the point of contact....

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Cheers Ross
 
Nice, I've seen some crazy set ups over the years.
Sometimes you run into a job that takes two minutes of machining and 40 minutes of set up.
That was a cool solution.
 
Years ago I bought a set of parallels that are small and round - I've always called them pucks. Bolt them to table to set plate work on. Hadn't thought of bolting them to the workpiece until reading this thread....

I will note one other related tactic that took me forever to think of - turn some round pucks out of aluminum, bolt them to machine table (spaced with a drawn plan), and then face them all with the machine tool in use - they're now as flat as the machine can make. Work gets clamped on top. Machining into the aluminum pucks is explicitly allowed - that's why they're aluminum. (I guess you could grind them too with the right sort of wheel, haven't needed to...)

@SteelrRn- the other day I did one where I timed it - 2.5 hrs to build the setup, 15 minutes to drill/tap/counterbore holes, 20 minutes to clean holes and insert bolts, 30 minutes to tear it all down. Part was for an experiment and it "failed" - but we learned from it, and that's what matters in the projects I do.

@AlfaGTA gets the gold star for finally showing a use for the little stem sticking up off the back of an interapid - I had always thought they were put there to annoy me!
 
Actually i like the round stem on the indicator....
For small circular indicating i hole the stem in an ER 16 collet and holder....
For magnetic base work...I have modified my Noga magnetic base
Drilled a 5/32 hole in the end between the dovetails . Have to also notch the clamp screw shank to allow the stem to pass.

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Looks like this when made up.....gives another joint so getting the indicator where you want it IMO is easier...

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Made a bushing that fits the 3/4" bore on by boring head that has the 5/32 hole and a plastic tipped set screw..
I use the bushing in the rear hole on the boring head slide (never use the boring bar in that hole) ...I have a thumb screw clamp that stays in the clamp screw hole...I put the indicator in that hole to dial up on a bore or check
that things are still true...can do this without removing the working tool.....

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Cheers Ross
 
Thanks for sharing Ross, these are my favorite posts !
Kind of like browsing the sample pics on the Deckel brochures, but with elaboration!

(I admit, some of the work shown in Deckel brochures....well, I am not sure how is was actually done, e.g. this one
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)

BR,
Thanos
 
Those nicely ground pucks doubling as clamps are cool. Also using them to stand off parts from the table makes the machine happy (less table scars anyway).

Devlieg drivers always stood parts off the table with the jewelry available. Many HBM jockeys do the same, 123 & 246 blocks work well. Lots of T-nuts with different thread sizes adds to the kit.

I’d almost always (working flange down on something) place or fasten 3 hard/ground things to the part, take it to the rock for inspection/markup and pack or jack the 4th (or more) standoffs. Then lift with the 3 hard feet & 1 locked jack to the machine, surface gage the bottom for still good, maybe place more soft jacks, clamp & off you go. No scars on the table top!:D

With large motors or pumps it makes no sense to re-machine the feet, one bump in handling/rigging & it’s out again anyway. (you DO make a notice that the thing has a soft foot for the millwrights benefit).

Good luck,
Matt
 
I have used both the pucks and the indicator mounted in the boring head with much success within the past month. Ross, thank you for posting and sharing your highly developed skill. Much appreciated.

John
 
Ross, your posts should be required reading for energy budding machinist, once again a very elegant solution.
You do certainly get entrusted with some remarkable and very valuable cars!
 








 
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