TESTING THE 720-12R WESTACH ROTOR SHAFT HALL EFFECT SENDER UNIT.

This sender can be simply yet accurately tested either in situ in the helicopter or as a “bench test”.  If in situ then it can be tested whilst connected to the rotortach and I’ll do a separate post for that that also includes testing the rotortach itself.

However this thread is for testing the hall effect sender when it is NOT connected to the rotortach.  It is a simple but important  fundamental test of the sender itself, and I think this is a particularly useful test when there appears to be some problem with the rotor speed display and there is a difficulty identifying whether the problem is actually with the sender, the rotortach, or the wiring.

All you will need is a multimeter, a resistor, a magnet, and a voltage source - anything between 5V – 12V.

NOTE:  the sender unit expects to see the South pole of a magnet.  It won't work with a North pole.

A few comments relating to the alignment of the magnet ring :-
1/  The active part of the hall effect sender is dead centre in the middle of the threaded barrel.  Ensure that your magnet ring is vertically aligned so that the centre of it passes over the centre of the sender. If it is too high or low then the sensor in the sender may not “see” the magnet.  There have been a couple of different styles of magnet rings over the decades, but the same theory holds.
2/  Don’t adjust the sender so that it is almost touching the magnets.  It’s not necessary.  The actual hall effect sensor semiconductor used in the sender is extremely sensitive to shock or any impact. If a magnet hits or touches the epoxy face of the sender it is likely to damage it. Typically 1.5-2.0mm gap should work fine.

Instructions are in the drawing.  Let me know your comments and if anyone has any questions.

Attached Files

  Hall Effect Sender test circuit.pdf (Size: 10.01 KB / Downloads: 6)

This is what I do, quick release on door hinge hardware

I am helping a friend who has been adding coolant on a regular basis, not a lot of coolant, but still needs topping up, we use a catch can setup to handle the coolant top up, ie the std RW surge tank is gone and in its place a standard racing catch can is installed where it can be easily seen. The catch can receives any coolant that is released via the radiator cap, then when all cools down that coolant flows back into the radiator, same idea as most cars. The catch can has a coolant level tube that can be seen so the owner knows it has lost some coolant. When he dips the oil tank no water is seen, the oil is visually as it should be. the only place where we see the creamy oil is in the oil catch can (it is connected to the vent tube on the oil tank and its job is to separate any oil in the fumes coming from the oil tank, it has a dip stick and we see about 2 mm of creamy oil when it is removed for inspection. We have pulled off the barrels and checked for cracks between the sleeves at the base of the barrells, no visible crack is seen, and inside the crankcase shows only oil, no creamy at all. So now I have run out of ideas of where the coolant could be getting into the catch can and only there??
Whilst we have the barrels off we plan to machine of the fire ring protrusion and replace with the solid full face gasket and studs, When looking at the talon engine set up it shows the solid head gasket and a base gasket, so I am wondering how much should be machined of the barrels to allow for these instead of the current no base gasket and the fire ring setup, any ideas??

As some of you know, I bought what was left of the wreck from Jim’s last year. Wentworth stripped a lot of stuff off it before I got. While taking the controls off the frame , I found that none of the studs in the ends had LockTite on them . One wasn’t even tightened down and was loose. It was improperly safety wired and had only one rivet in it and wasn’t even the proper rivet. Some of them had no rivets at all. All except the loose one did seem to be properly torqued, so 5 out of six ain’t bad, but the loose one was on the cyclic.
This ship was built in Fla. I hauled it to California over ten years ago where it was finished and I actually did a first hover in his back yard. I don’t think it ever flew much there. Then it went to Texas and did fly a get bit there I think. This ship went thru two owners and this thing had these issues till the end.
Right now , I have a ship that had videos of it doing a short flight and declared ready to go. It actually had bolts in the cyclic control that didn’t have nuts on them.

If you buy a ship and you don’t know for sure what’s in side, especially the controls , better check it out really good.

I’m working on track and balancing and two manuals have two completely different ways of doing it. The documentation on this site says panels 2-7 from the tip are for controlling blade tip and tracking while panels 8-16 are for collective stick pressure. However, the pro balance system manual for Rotorway has those panel ranges but the panels by the tip (2-7) are for collective forces. The dynavibe Rotorway manual doesn’t mention the reflex panels. Anyone know which is the correct way to track and balance Rotorway blade? Thanks

Nick

Our first event was  2019! getting to be a habit! I hear a lot are coming but only 8 have registered.  Planning really needs as close an approx as possible! https://hardy-field.com/  I have to fill my tank soon.  Sure hoping price will drop soon!   

Attached Files

  MGC2026 Brief.pdf (Size: 8.03 MB / Downloads: 4)

Looking for a little help from the experts or people who have experience with this later version Cog Belt Tensioner.   

 I'm building an A600 from two incomplete kits.   The construction factory videos are made with a much earlier setup so they don't help.   The factory construction manual, specifically Section 15 dated Jan 2017 Page 4, Photo #5 starts the process by asking me to refer to Print E49-8600 and card E49 Card 3T, which I do not have (did not come with my set of documents when I purchased this kit from RotorX prior to them folding.   I appear to have the actual parts, minus the "Tension relief block tool (E49-8681) that are shown in the construction manual.   

Does anybody have a pdf or photo of the construction card and factory drawing the instructions referenced--Print E49-8600 and card E49 Card 3T?
A photo of the tension relief block tool along side a ruler would help.  If it's just an installation tool, Maybe something I could fabricate?

Thanks
Sam

Just had a fellow bring-in a set of main blades that have in the factory box for probably over 30 years. They might have been salvageable except for some corrosion on the leading edge that had actually bubbled up near the root end. I used a grinder to take it down almost 1/4” before I got to good metal.
You must probably store parts if you want them to be any good years down the road. Rust and corrosion can destroy new parts that aren’t kept on a good environment.
These blades were so old they needed the doublers glued up and all the rivet mods done. The trading skin had the plastic on them and was perfect under that. The spar had some corrosion, but no use really seeing how bad it was after we found the bad patch near the end.
Properly stored these would be worth over $10k today.
If you have parts, better pull them out and check their conditions. If your buying parts that the seller says are new, better check them out before you determine price. May be worth nothing except junk price. I allowed the owner some money on these for a new set.
I once built up a mock up EXEC that went on Christine Onassis yacht hotel in Rotterdam, Netherlands .
If you go to
Her website you can probably still see sitting on the helipad. So that’s what these may be used for , yard ornaments.

Sadly today another RW accident, this time it was the rubber hose coming off the U shape aluminium pipe feeding the heads, the hose blew off on final approach about 20 feet in the air up till this point all temperatures had been in the green, the engine faltered as it was sprayed with coolant. The pilot managed to get it to the ground with some great piloting skill by keeping forward momentum as the RW hit the ground, the landing hoops folded backwards and cushioned the hard landing. The landing gear did what it was designed to do fold back and absorb some of the impact, so all that was damaged was the landing hoops and skids, it makes me realise that if those hoops had been reversed the damage would have been a lot more as it probably also would of damaged the frame and whatever was attached to that frame