New Project, New Tools

So… Can you build a few of these?  Like, maybe… 30 units?

Um, Ok.

The device is an ‘Auto Chamber’, used for sampling soil gas emissions.  In this case, they are used to determine how much CO2 is released from differing soil types.

(Proper credit for the original and subsequent designs will be attributed in due time…)

So  I have a small manufacturing situation starting, oh, right about now (8/16/12).

This should be fun…

Approximately 800lbs of aluminum, poorly secured…

…At least one piece went missing along the way.  A few nicks dents, and bends as well.

Many parts, and many cuts, miters, notches, etc.  Early on, the estimate was in excess of 2k separate ‘cutting’ operations.  And then the scope of the project changed, so that number went up.

This is the type of situation that justifies a better means of sawing. Stock and time loss involved with band sawing and secondary cleanup on the mill would be ridiculous. The more I thought about it, the more I wanted a cold saw of some sort.  After quite a bit of thinking, researching, ebay watching, bidding, losing,  and scowling, etc, I made a deal on a Scotchman 350.  This saw has far more capacity than needed for the immediate project, but I figure if I’m spending that kind of money, I might as well go right to the endpoint.

I don’t think any machinist/fabricator ever wished they had purchased less capacity in a tool…

Coldsaw…   Looks almost new.

…Oldsaw.  Vintage gear-drive Homelite with 42″ bar and 1/2″ pitch chain.  Not appropriate for aluminum.

The dedicated blade and flood coolant should arrive in a day or two, and then the ‘fun’ begins.

(8/17/12)  The blade and coolant show up on the same Brown Truck. Shipping rates seem to have gone up…

This pile needs to become more useful by way of size reduction.

The first 60.  This batch went slow, as I was getting the feel for feed rate etc.  And I was trying not to tangle the 8 ft stock in the bicycles hanging from the ceiling.

The first 60, then 30 in the  middle, and then 60 in a Jenga pile on the top.

The bucket holds 30 channel sections, and 60 angles.  The box holds 60 flat strips, and 60 channel sections.  Each sort is of a particular type and length.

This batch of 120 needs a 45 degree mitre at each end.

The remains of the day…

…And the chips.

Another view of the cutting station.

Hastily produced floating stock support.  The idea is to prevent the ‘legs’ of the channel collapsing under tooth load.

So far so good.

I’m really glad not to be using this band saw for the job.  The shop foreman would have nowhere to rest/roost.

This is George, the neighborhood Guinea hen. Note the complete disregard for shop safety.  No eye protection, bare feet (cleverly hidden once the camera came out), and plenty of loose clothing to get snagged in the works.

If I were cutting only one or two parts, I would have used Tapmatic aluminum formulation, as it makes for a smoother cut.  I also suspect that the saw blank may have arrived at the grinder slightly out of round, as it feels and sounds like it has a slight hitch in its stride.  And every so often it gets a piece of spinach stuck in its teeth.  No matter though, as the cuts are all consistent, and I’m still learning how to run the saw.


Scotchman making chips:

Cutting angle

Cutting  U-channel


120 out of 240 mitre cuts.

Quick fit up without second operation.


Notching on the K&T:

The assembly requires 240 sets of notches; some singles, and some paired.  These allow the legs to interlock with the main frame.  These will be done on the horizontal mill, with a pair of dedicated slotting blades.  The stock exceeded the .125″ specs called for in the drawings, so custom blades were sourced from Thurston Saw, out of Rhode Island.  The blades arrived on the exact day promised three weeks prior by the sales representative.  I suspect they appreciate the business…

Squaring up the vise to make a set of jaws.

Setting up the vise after making the jaws.

Completed jaws in their working position.  These will leapfrog for the two separate notch orientations.  The pins locate the work.

Blade/arbor setup and coolant manifold.

Quick and dirty coolant pump/reservoir.  At one time this was a self contained hydraulic power system, recovered at the local scrapyard.

The coolant sump on the K&T is still sludged up from its previous career, and this was the quicker route.

Corks keep the coolant from running off the sides of the table.

Notching rear brace.

(Closer view).

Two of 240.

Notching the rear leg.

Fit check.

Vise jaws configured for side slots.

This part of the project was rather tenuous, as I couldn’t afford to damage the blades due to the lead time for replacements, combined with the large amount of stock involved.  That, and the same blades were needed for another operation.

Each slot set ran less than two minutes including load/unload.

Hinge pins:

This part was produced on the Warner & Swasey turret lathe.

Center drill.


Advance to the length stop, and lock the collet (the stock is six feet of .75 square stock).

Turn the first diameter.

Change tools to a sharper corner radius and cut second diameter.

Parting off.

Deburred and cleaned.



Partially completed.

One of two slots cut prior to bending.  The second slot terminates in the small hole above and to the right of the first slot.  Slots cut on the Scotchman after vise jaw modification.

The head on the saw swings 180 degrees.

Making the draw pin/head for the bender.  The hardened bar stock came from  a damaged backhoe steering cylinder.

Test bend.

The tab in the center is waste, and will be removed on the corner notcher.

Detail of terminal holes and radius relief.

Right-wingers and leftists, meeting in the middle.

Delrin Hinge bushings:

(Also produced on the Warner & Swasey)

The delrin bushings are too large to hold in a collet, so I made a set of jaws for a universal 2 jaw chuck.

Rough layout and centering. The jaw halves have already been indexed to their respective master jaws.

Roughing in the pocket.

Finished pocket with corner reliefs.

The two jaw chuck.

Cutting Delrin blocks on the Scotchman.

Blanks after two separate cutting operations.

Milling to the finished thickness.


Drill to rough id.

Bore to finished id.  In retrospect, I should have done this with a reamer.

Cutting the shoulder.

Done with the hard part.

Drilling and tapping to #10-32.

Class photo.

Bushing installed in the Mid Leg.

Hinge assemblies.

Hinge/Mid Leg assembly.

Welding, Part 1.

Water Trays:

The water tray serves as a gasket between the chamber lid and the main frame.

Each tray has 1 foot of weldment, so the completed assemblies account for 30 feet of weld.

This right angle clamp assembly is mounted to a swiveling, tilting base.  Quite the time saver.

Flipped up.

Back view.  The hand wheel to the right locks the fixture, while the lock pin to the left selects a repeatable angle.  The lever in the center releases the grip on the ball mount for additional angle adjustment.

This test weld was done on straight Argon.  The balance of the job was done with 75/25 ArHe.  The weld total for the job is right around 165 linear feet, plus or minus.

George, stress testing the welds on water tray halves.

Completed water trays.

The main frame on the welding fixture.  The Kearney & Trecker makes a nice adjustable surface to hold the fixture.

The idea being that the operator can work from a comfortable position.

The two sections of channel bolted to the right angle clamp serve as rests for the torch hand.

The first round of six ready to ship.



Simple fixture for drilling holes in diagonal brace material.

‘nother view.  ~10 seconds/hole.

Quick clip: Drill fixture for brace straps

Ends clipped.

Setting the work stop on the Enco.

Alignment stop to the right.

One end done.  There is an ajustable stop on the brake leaf to set the angle.

Both ends bent to like angles.

Ready to go.

Attached to rear leg.


The blanks for the spring retainers, spring adjustment plates, cylinder mounts, and pull plates.


Pull Plate:

This piece mounts to the inside of the lid, and serves as a reinforced attachment point for the rod end of a pneumatic cylinder. Each plate has four holes drilled and tapped # 10-32.  I used a combined drill/tap in a Tapmatic SPD 5 head.

Spring Adjustment Plate:

Four holes tapped #10-32, one cross hole to hold the spring leg.

The dark pin to the right of the work piece is a stop in the dedicated vise jaws.

Another view of the vise jaws.

Parts done.

Spring Retainer:

Clipping one leg on the Scotchman.

With notches milled.

Mounting hole.

Clipping the short leg on the Scotchman. ( A vise in a vise).


Cylinder Mount:

Thinning the clevis end.

Nose radius fixture.  This is mounted on a small rotary table.


Cutting the nose radius.


Detail of center pin and swing stop.

In the pocket to cut the clevis slot.  A ‘waste tab’ is visible to the right among the chips.

Begin slot.

Slot finished.

Group photo.



Welding, part 2.

Lids: (Little boxes…)

Folding boxes/ on the Enco/ and they’re all made of 5052/ and they all look the same.

There’s a silver one/ and a silver one/ and a silver one/ and a silver one/ and they’re all just the same.

First fold.

Second fold.

Third fold.  This break has a capacity of only 4 inches.  These lids are just shy of 6 inches in depth.

You might notice the Sawzall in the picture…

I notched the upper frame to provide clearance for the first two folds.  Given the replacement cost of the brake, compared to  the scope of the project, it seemed like a good idea at the time.

What’s your clearance, Clarence…?

Fold four.

Lid welding jig.

Finished weld.

One set ready to go.

Silver boxes/on the jump shear/ and they’re made out of 5052/ and they all look the same…

And the more or less finished product.  The gas sampling apparatus will be linked up in the field.