Electromagnetic Dent removers-Advice

[johnkay]

Hi there,

Does anyone out there have any advice on Electromagnetic Dent removers for use on Boeing and Airbus aircraft. We have a policy in our Airline of cleaning up all dents within the SRM limits but have found that filling with potting has not been effective and has caused more problems in the long run. If these so called Electromagnetic Dent removers could prove to be effective in removing dents without requiring additional work such as painting etc then we would like to look at it as an option. I have only managed to find two companies, Fluxtronic and ElecroImpact and both there products based on their reports seem to work. Has anyone out there used them before and have any recommendations

Thanks

John

 

[Fluxtronic]

While I am biased for advice I will give free demonstrations and can also put you in touch with an airline that owns one. Next week we will exhibit at the MRO in Dallas, TX: April 20-21.

I am an engineer (Fluxtronic) that formerly worked at Electroimpact and felt the technology needed improvement. We can remove dents that Boeing never could.

The EDR technology actually originated at Boeing in the 70's - 80's. From a decade with different economics and policies, the EDR is in several Boeing (McDD) SRMs. Boeing owns several machines and pulls dents internally, factory new aircraft and lease or buybacks they own. Former McDD licensed the technology and took a machine on the road pulling dents from business aircraft. Ask Boeing about dents today and you might get the 787 marketing dept, but the former McDD group still tries to pull dents. Airbus has shown some interest. The economic interest for removing dents naturally resides closer with the airline or aircraft owner.

 

[johnkay]

Thanks for the info Fluxtronic. Some contact details would be great especially with Airlines who have one and of course someone at Fluxtronic who we can perhaps communicate with directly via phone or email. Demonstrations would be great but being located the other side of the world in South Africa I guess would be difficult for you to arrange.

 

[CRACKKILZ]

In a former life I worked as a Liaison Engineer at Douglas on the MD-80 program so I am somewhat familiar with the capabilities AND LIMITATIONS of EDR.

Based on my experience, unless there have been some drastic improvements, I would be very reluctant to spend capital resources on such a machine.

In liaison we would call the EDR team and they would show up in their "ghost busters" vehicle and as I recall mostly they had excuses as to why EDR would not work for this particular dent configuration. Limited access to the area, too sharp a dent etc. etc. etc. It got to the point where the whole process was a running joke in the engr dept.

A large percentage of the time the EDR team would not even attempt to pull the dent. And when they did, the rework was often less than perfect.

I'll bet that only 20% of your dents would be good candidates for EDR. I doubt this is what you are looking for. Also, you must ask yourself.... this technology has been around for quite sometime so if it really works why hasn't EDR gained widespread acceptance in the mfg and airline/GA circles?

Sorry to sound overly pessimistic, I am only relaying my own personal experience. I am sure there are other professionals out there that would disagree with my views.

 

[Fluxtronic]

Yes we (Fluxtronics) have made significant improvements over the other machines. While not perfected, for example we removed a leading edge hail damage dent .150" deep x .75" wide, .062" thick, which is estimated about 10% material shrinkage.

In fact you can view a few here:

http://www.fluxtronic.com/sample.php

Since this is an engineering forum and few have maybe seen this method:
The EDR shrinks the aluminum by distributing impulse forces inside the material. This is done entirely from the outside by penetrating with a large magnetic field and rapidly collapsing it. The force is a impulse, applied in an adjustable and controlled manner. For a traditional metal working method like an English wheel, hammer, or PDR spoon, the forces are normal and concentrated on an outside surface, which does not directly shrink material. With the EDR the magnetic field has a soft gradient so there are no discontinuous edges.

The strength and fatigue life is improved by returning geometric strength and distributing stress back through the material. There is significantly less residual stress than trying to remove a dent by other methods. Certainly there is work hardening when the dent is made and removed. For dents made with some velocity the EDR is usually relieving stress around the dent.

The repair is usually paintless. I attempted a fairly deep golfball dent (literally) .11" deep on the side of a T-34 with maybe a 50yr old paint... and the paint did split and flake off. So it depends on the paint and severity.

We are touring the US pulling dents, happy to give demonstrations when we get a chance.