A Bumpy ride

At Indrotech we feel it our duty to educate the industry on what faults we look for on a problematic driveshaft and how and why we rectify it.

Here is a fault that we find with a typical truck drive shafts.

The fault either comes from neglect to service it, normal wear and tear and believe it or not, even as new from the Original Manufacturer. This fault creates a massive vibration causing failure to the shaft components like; universal joints, centre bearings and even the driveshaft itself. That’s why we always stress that shafts need to run geometrically true to avoid this from happening.

Our first step is to look at the overall concentricity of the assembly starting from the straightness of the tube to the concentricity of the other components welded to either end of the tube. It does get technical and tedious to fix but it must be right, otherwise we come up with the problem that you saw in the video.

The benefit of our procedures is reducing this obvious runout down to 4 thousandths of an inch, equivalent to 1/10th of a millimetre. This is a standard service we practice within our Manufacturing Process let alone our Balancing Procedure.

This procedure helps with our final balancing process that in turn eliminates any vibration in the truck that is caused by the driveshaft. In the video we are running the shaft only at a couple of hundred RPM, imagine what effect it would have running at 3 or 4 thousand RPM. It would be dangerous on the road and more than just a bumpy ride for the driver; it could be catastrophic!

Please refer to our last post so you can see how a shaft, whether a single piece, 2 piece, 3 piece or 4 piece should run. 3 piece driveshaft balancing


Ford and Holden two piece shaft bearing change

Indrotech is finding that there are more and more Ford and Holden two piece shafts that require centre bearing changes. If you feel a vibration through your drive train, it’s most probably a failed centre bearing. We replace Ford BA, BF and FG Falcons. The most common Holden are VX to VE models.

This is what it should look like.

This is a more cost-effective way to keep your car on the road rather than spend several hundreds of dollars replacing a new one. Let’s not forget, once the CB has been changed over, the shaft needs to be balanced.

Ford-holden-Centre-bearing Ford-holden-Centre-bearing-fixed



A Truly Reversible Axial Recirculating Impeller

Now the completed product.

Upon completion, my aim was to test run it to make sure the impeller worked. As I suspected, it worked perfectly rotating in one direction and when reversed worked just as good. What this means is that the impeller gave exactly 100% of its airflow whether it’s rotating one way or the other in the desired direction. Now it sits in an Industrial Oven recirculating hot air in either direction maintaining a constant air flow and temperature without the need for 2 fans to alter the direction of the air.

The setting up of the truly reversible axial recirculating oven plug fan.

t1 t2

t3 t4


Schenck H20 hard bearing balancing

Indrotech Pty Ltd is proud to announce their new addition to their Industrial Balancing facility; a Schenck H20 hard bearing balancing machine backed up with a CAB 590 measuring unit.

Indrotech, Australia’s leader in Industrial Rotational Technologies, Industrial Fans, Industrial Balancing and Driveshafts, have today confirmed this new addition has now been commissioned. The H20 was introduced to the workshop to handle the smaller rotating components that require balancing such as drive pulleys, electric motor rotors, small pump impellers and small turbine wheels of maximum weight up to 50kgs. Having the sensitivity of its ‘big brother’  in the workshop, the H4, it can comfortably achieve grades of balance as low as G0.4 to the ISO Standard.

The key features of this machine are:

  • Selection of 4 speeds;
  • 1500mm long bed;
  • 800 maximum diameter
  • Digital readout;
  • 3“ diameter high speed crowned rollers.

“At the moment, it’s a dedicated direct drive machine. The next step from here is to incorporate a belt drive system. This will allow the work piece to “float” on the rollers eliminating any external drive influences that may compromise accuracy”, said Dennis Eliopoulos Managing Director, Indrotech. “Not that the direct drive system is inaccurate but when we’re balancing light weight, small diameter components, it’s better to belt drive them at very high speed. The bigger diameter components have no issue with direct drive”.

Dennis added that, “the introduction of the H20 now allows us to free up the H4 from the geometrically smaller jobs. This way we can balance more rotors in the equal amount of time. I like this because that’s what my customers want; fast turnaround.


We were fortunate enough to pick up this machine from an ex fan manufacturing company, Flakt Woods who I considered as “the Rolls Royce” of the fan industry…”


A Blowing Success

Foundries are generally inhospitable environments. Indrotech were approached by Geelong based foundry IXL Metal Castings to design a solution to the heat build up and replacement of internal environment in the foundry caused by pouring molten metals and sand shakeout processes.

There were several unique challenges in the design parameters that took several months to resolve.

  • The location of the fan
  • Capacity to replenish the air several times per hour
  • Ensuring the noise factor was kept within the required decibel level for a residential area.

The initial design featured a roof mounted install with 5 branches extending the length of the foundry. This option offered a straightforward installation however IXL were concerned about the potential noise particularly as the foundry, which is sited in a residential area, sometimes operates past 9pm. Despite our assurances that our silencers would ensure the fan operated within the required decibel level, their concern was that any complaints would result in a costly relocation of the system.

Their next option was to install the system in a restricted space at the rear of building (solving the neighbourhood noise issues) however the size of the fan and ducting required made this impractical.

Finally it was decided to site the fan at the top of the ceiling inside the foundry – solving the potential issues of noise and space limitations. The downside was the added cost and difficulty of the installation – requiring internal scaffolding and working outside the foundry hours to minimise the interruption to business. Once the location had been confirmed the design was finalised. We fabricated a 56” diameter heavy duty belt driven axial fan with inlet and discharge silencers, plus mounting feet to assist in the installation. The installation itself took several weeks but once the fan was commissioned we arranged a site visit.


It gives us great pleasure to see the fruits of our labours in place – initial testing confirmed that the fan was capable of replenishing the air in the foundry 5 times per hour, and decibel levels well within operational limits.

The positive impact of the fan was immediately evident as we climbed to the top of one of the foundry’s hoppers to get a closer look at the system – being able to breathe easily and talk normally in a previously harsh environment. It has been a pleasure working with the team at IXL Metal Castings.

“Since we installed the Ventilation Fan into the highest point of our Casting Plant Building some months ago, we have experienced much change in our Internal Environment. The accumulation of hot air produced by melting, pouring and cooling castings now by natural convection makes its way to the high points and is quickly extracted from within. We are able to (and it is necessary to) leave doors open, fix shutters and vents open to allow sufficient in rush of fresh air to replace that what has been extracted. Operator comforts are at a much higher standard and a very pleasing result. Thank you Dennis & the team at Indrotech for your design and supply assistance”.

Jim Miller, Engineering Services Supervisor at IXL Metal Castings


We’re pumped!

At Indrotech we love a challenge

We were approached last month by a customer seeking an alternative to the hydraulic arrangement in their mobile water pump system which would be more cost effective to run.

Our design team set out to create a robust system which had to be a long lasting efficient solution and of course the focus was on reducing the ongoing running costs.2-piece-dshaft-layout

Our solution was to produce a mechanical system comprising a 2 piece drive shaft assembly operated by a pulley drive system mounted on its own shafts with industrial pillow block bearings. The team also provided an innovative solution to the noise factor, which was achieved by selecting the correcting belt drive system which included the correct profile to transmit the power.

The customer provided us the design parameters to work from and our technical engineers tailored the system to fit.  Cross members were fabricated for the bearings supports to mount on.

The customer was delighted with this new solution which offered both minimal ongoing maintenance and a cost benefit to boot.

This is why we get out of bed in the mornings! (Well, that and coffee).


It’s a matter of balance

A day in the life of the balancing machine! First up – The Thresher, workhorse of farm equipment, like all rotational equipment if it is out of balance it won’t operate at optimum capacity. The damaged metal fingers get replaced and after a short crane ride it’s ready to go back on the farm.

Next up the delicate blade of a cheese slicer takes its place. The balancing tolerances are a lot finer and extra care is required to bring it into balance.