Precision Shafts to Get You Running Again!

They say “wheels make the world go round”, but without shafts, nothing would ever move.

 

3D Render of Shaft

 

 

 

 

 

 

 

A shaft connects a mechanical power source to gears, wheels, turbines, rotors and much more. Shafts can be as simple a basic round bar or as complex as containing exacting bearing fits, keyways, sleeves, grease fittings, snap ring grooves and splines.

 

Broken Shaft – Removed from Assembly

 

 

 

 

 

 

Often, the shafts we see have been in service for many years, sometimes running non-stop. Unfortunately when these older shafts break (as shown here), there aren’t drawings available and not a lot of time to get the new shaft machined and the unit running again.

 

Half a Shaft – Part A
Half a Shaft – Part B

 

 

 

 

 

 

 

 

 

This shaft broke and we got it in 2 sections, still in the housing. After disassembly, we made hand sketches. While the housing was cleaned and checked, we created 3D drawings and then machined a new shaft.

 

Shop Sketch of Shaft
3D CAD Drawing of Shaft

 

 

 

 

 

 

 

 

 

 

Here is the new shaft ready for inspection. After passing final inspection, the housing was reassembled and the unit was ready for production use.

 

Finished Shaft – Ready for Unit Assembly
Shaft in Assembly – Almost Ready!

 

 

 

 

 

 

Hopefully a broken shaft won’t take one of your machines, or worse, your facility down. But if it does, Riggs Machine has the experience to get you running again.

 

Final Assembly – Ready to Ship
Final Unit – Assembled

 

 

 

 

 

 

 

 

 


Riggs Machine & Fabricating – Serving industry in KY, OH and WV for over 45 years!

Shims – more than just a strip of metal

SHIM – A washer or thin strip of metal used to align parts, make them fit or reduce wear.

 

a new shim set – ready for installation

 

These, sometimes extremely slender, strips of metal are very crucial in industrial operations. From getting a pump to line up perfectly or to make a surface level, a shim must be exact.

 

don’t let your shims get this bad!

 

Shims come in a variety of materials, but most commonly from metals such as carbon steel, brass and stainless steel. And they also vary greatly in their thickness from up to 1/4” thick and down to .001 thick (imagine an industrial foil).

 

.003 thick shims – for precise applications

 

And the tolerances they must hold are key to their functionality. They cannot deviate across the surface, their dimensions must be held.

 

 

Often industrial shims come in sets of varying thicknesses. They can be added individually to get the final adjustments perfect.

 

a pack of new new shims

 

They also come in many different shapes, often having to be custom designed to fit around existing bolt holes and other features. We like to add the small hand holds (show below) to make installation and adjustment easier.

 

custom designed shims
pump shims w-install tabs

 

 

 

 

 

 

 

 

 

At Riggs Machine and Fabricating we understand Industrial Shims and their importance in setup, maintenance and repairs. We understand the tolerances and design elements that separate a shim from a strip of metal. Yes, there is a difference. If the shop you are working with now doesn’t agree with that, then you are working with the wrong place. Time to call Riggs Machine.

 


Riggs Machine & Fabricating – Serving industry in KY, OH and WV for over 45 years!

Rail Welding Shears

Used when creating a Butt Weld between two sections of train rail, this shear takes a lot of abuse. At the same time, it must follow very tight tolerances to maintain the profile of the rail (especially when a high speed train is running across it).

A New Rail Welding Shear

 

 

 

 

 

 

 

 

A butt weld is created in the field using a mobile electric flash-butt welder. The two sections are joined and electricity is applied to the rail ends. The flash-butt welder squeezes the sections together at very high pressure, permanently joining them, but this also creates a seam at the joint with a segment of slag.

Rail w/Hot Slag after Butt Weld
(notice the manual shear in the background)
“Thermite Rail Welding” by PetrS. 2013 licensed under CC

 

 

 

 

 

 

 

 

 

 

The RAIL WELDING SHEAR is clamped onto the rail and slid along the rail, by the mobile welder, cutting off the hot slag leaving only a small remainder that will be later ground smooth.

These shears are precision cut out of Nitronic 60 – a high strength metal known for it’s wear resistance – with a wire EDM machine. The EDM unit cuts parts slower, but with more precision than a waterjet or laser cutter.

EDM test for part fit-up

 

 

 

 

 

 

 

 

 

The final grooves are added via a CNC and the units are then inspected. A hard-surface weld is added and machined to create a precision cutting edge. The parts are assembled to complete the rail welding shear.

Rail Welding Shear Components
More Rail Welding Shear Parts

 

 

 

 

 

 

 

 

 

 

These are ready for the rail and making the travels of passengers and goods go smoother and safer.

Rail Welding Shear – Top
Rail Welding Shear – Side

 

 

 

 

 

 

 

 

 

 

This video shows a portable flash-butt welder in use. Notice the Rail Shear clamped on the rail before the unit is lowered on the section.

 


Riggs Machine & Fabricating – Serving industry in KY, OH and WV for over 45 years!

Tapered Tube Plugs – Not as Simple as it Seems

Tapered Tube Plug

 

 

 

 

 

 

 

Used during repairs and outages, this simple looking device becomes a necessity. The Tube Plug is hammered or welded into the open section of pipes in boilers and heat exchangers. They plug the end of the pipe to either stop the flow of steam or coolant. If the plug’s seal is not tight the coolant can seep into the material and contaminate it.

 

Heat Exchanger End *
Heat Exchanger Side *

 

 

 

 

 

 

 

 

What makes this seemingly basic item so important are a few factors. First, its fit must be right. Sure they are tapered, but they must fit without damaging the existing pipe or sliding too far in. Also, the material specifications for Tube Plugs can vary greatly. While some plugs can be made out a carbon steel like 1018, other plugs must match the existing pipe section (i.e. A350 with more carbon content) or even stainless steel, nickle or other metals. If the wrong type of metal is used, it could lead to corrosion, rust, leaks or a possible reaction with existing materials in the system.

 

Tube Plug in CNC Lathe

 

 

 

 

 

 

 

 

Even the machining isn’t always as simple as it may seem. Bar stock in not always available in a size close to what the job requires or the material type needed is only available as plate. In that case, a plug larger than the finished size would be cut from the plate and then turned turn by hand on a lathe. Time consuming, yes, but necessary for a professional fit.

 

Plug cut from plate
Sample Heat Doc

 

 

 

 

 

 

 

 

 

 

At Riggs Machine & Fabricating, we not only have the experience, but we ask the questions to make sure the job is done right, the first time. Don’t trust those supposed simple jobs to just any shop. Call Riggs first for the dependability and quality your facility demands.

 

Set of Tube Plugs

 

 

 

 

 

 

 

*(Morton, John, 2 Electrolyte Heat Exchanger Tube Bundles in the 8×6 Foot Wind Tunnel, 1975) – http://catalog.archives.gov

 


Riggs Machine & Fabricating – Serving industry in KY, OH and WV for over 45 years!

Explosion Proof Hatch – Pyrite Ducts

Here are some newly machined explosion-proof hatches for pyrite ducts.

In preparing coal for energy production, pyrite, a sulfide that contributes to air pollution and acid rain, is removed before burning. The separated pyrite is forced through ducts to waiting hoppers using high pressure fans. These ducts have negative pressure in them. If a chunk of pyrite gets stuck in a hopper then unit has to be shut down and the duct removed from the unit to be cleaned.

Photo by James St. John / CC by
Sphalerite-Pyrite

With the addition of these hatches, if a chunk of pyrite gets stuck in the hopper, it is only a temporary shut down while the hatch is opened and the material is washed out. Once the hatch is sealed, the unit is quickly brought back on-line. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

These hatches have also been used as inspection doors on gearboxes, giving quick access to the internals for routine maintenance or adjustments. The locking tab on the hatches also helps keep the unit secure.

 

A Phonographic Finish!

No, not what is used when a race is too close to call (that’s a photo finish). But a machined finish added to the raised face on a flange to give an extra level of security to prevent leaks and maintain effective seals.

Spacer Flange w-Phonographic Finish

The Phonographic Finish is actually a serrated finish, either concentric or spiral (much like the grooves on a record), that will grip the gasket between pipe sections firmly.

Phonographic Finish – Close Up

These finishes are typically added on a lathe to specifications set either by the company ordering the flange, the manufacturer or ASME B16.5 guidelines. Below is a render of the completed flange with bolt holes. I would have included a photo of the actual completed unit, but as soon as it was finished, it was rushed to the job site! But that’s why we’re here. Everyone knows who to call when a custom part is needed in a hurry.

Spacer Flange – Render

 


Riggs Machine & Fabricating – Serving industry in KY, OH and WV for over 45 years!

Stripped Industrial Bolts

Industrial Fan Housing

Stripped Industrial Bolt

 

 

 

 

 

 

 

Ever strip a bolt? Frustrating! How about a 22″ long x 3 3/4″ wide heat-treated bolt on an industrial fan housing? Nightmare!

Fan Housing on the VMC
Fan Housing on the boring mill
Drilling Out a Bolt
Drilling Out a Bolt

 

 

 

 

 

 

 

 

 

 

 

Not many shops have a horizontal boring mill large enough to handle components this size. But it’s just another day at Riggs Machine.

Industrial Bolt Cut
Industrial Bolt Cut
Catfish
Catfish

 

 

 

 

 

Next time you’re staring down the wrong end of a broken or stripped bolt the size of a catfish, you’ll know who to call.