Blades balancing

Bartek

Newbie
Joined
Feb 10, 2021
Messages
7
Location
Poland Warsaw
Hello everyone,

I am new to this forum. I'm building my own gyroplane and I'm doing fine, I'm almost done. There is still electrical installation to do, but this is make by a specialist, my colleague. However, I have a problem with the rotor blades, namely with their balancing. I bought the raw aluminum blades without weights and do not really know how to balance it. The blades has two 12mm and 8mm diameter holes (4.72in and 3.15in). I know I have to thread these holes and screw in the balancing bars, but I have no idea how to choose the weight. Planned autogyro parameters below:

Empty weight: 240kg (529lb)

Rotor length: 8.5m (27ft 10in)

Rotor width: 20cm (7,87in)

Engine power: 130hp

I add also some pictures of my vihicule and the blade.
I would be very grateful for any suggestion how to do that.
 

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Brian Jackson

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GyroBee Variant - Under Construction
Very nice looking. I don't remember seeing a prop shaft set up like that before with a pylon. Have you run the prop on it yet? I'm curious how it behaves. Sorry to go off-topic for a minute.

Welcome to the Forum.
 

René

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Joined
Mar 2, 2016
Messages
57
Location
PREVESSIN France
Aircraft
autogire
Total Flight Time
350
Hello Bartek I have built several rotor blades with the same blade profile as yours.
the internal bars are made of steel and have a length of:
diam. 12mm long. approx. 1.50m
diam. 8 mm long. approx. 2.20m
these bars are glued with ARALDIT towards the side opposite to the axis of the rotor, i.e. at the end of the blade,
At each end of the blade, holes 12 and 8 are threaded to M14x1.5 and M10x1.5 to fix and glue grub screws
in the rotor side blade and fixing feet you must insert and glue with the ARALDIT in the rectangular profile an insert of about 300 to 400mm to obtain an effective clamping of the blade.
Finally, balance the blades



EXAMPLE
panavia-doc1-23c8a69.jpgpanavia-doc2-23c8ac0.jpg
 
Last edited:

Rattler 1

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Joined
Aug 17, 2016
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130
Location
USA
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C150-C172-Taylorcraft-Tbird-Rans S9-challenger-Benson-Air Command-Sportcopter
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Sport Copter has a really nice video on how they balance their blades. Go to their web site under Rotor blades. Video called Tracking your rotor blades.
 

Bartek

Newbie
Joined
Feb 10, 2021
Messages
7
Location
Poland Warsaw
Very nice looking. I don't remember seeing a prop shaft set up like that before with a pylon. Have you run the prop on it yet? I'm curious how it behaves. Sorry to go off-topic for a minute.

Welcome to the Forum.
You mean how the propeller is powered? I haven't started it yet, but I used the same propeller drive in paraplane and it worked well.
 

Bartek

Newbie
Joined
Feb 10, 2021
Messages
7
Location
Poland Warsaw
Hello Bartek I have built several rotor blades with the same blade profile as yours.
the internal bars are made of steel and have a length of:
diam. 12mm long. approx. 1.50m
diam. 8 mm long. approx. 2.20m
these bars are glued with ARALDIT towards the side opposite to the axis of the rotor, i.e. at the end of the blade,
At each end of the blade, holes 12 and 8 are threaded to M14x1.5 and M10x1.5 to fix and glue grub screws
in the rotor side blade and fixing feet you must insert and glue with the ARALDIT in the rectangular profile an insert of about 300 to 400mm to obtain an effective clamping of the blade.
Finally, balance the blades
Thank you very much for your advice. I will definitely use it. My profile is slightly different than the one you uploaded in the photo. Do you think that in my case it is necessary to use rectangular profile to effective clamping of the blade?
 

Gyeric805

Member
Joined
Dec 15, 2018
Messages
27
Location
Albany
Hello everyone,

I am new to this forum. I'm building my own gyroplane and I'm doing fine, I'm almost done. There is still electrical installation to do, but this is make by a specialist, my colleague. However, I have a problem with the rotor blades, namely with their balancing. I bought the raw aluminum blades without weights and do not really know how to balance it. The blades has two 12mm and 8mm diameter holes (4.72in and 3.15in). I know I have to thread these holes and screw in the balancing bars, but I have no idea how to choose the weight. Planned autogyro parameters below:

Empty weight: 240kg (529lb)

Rotor length: 8.5m (27ft 10in)

Rotor width: 20cm (7,87in)

Engine power: 130hp

I add also some pictures of my vihicule and the blade.
I would be very grateful for any suggestion how to do that.
I used a firearm powder measure to weigh my weights used computer to convert from grains to grams , guess you could do the same to convert from grains to ounces , have seen water level in pvc tube being used to work out which blade is heavier or lighter but needs to be in draft free place (blades lifting devices )
 

René

Active Member
Joined
Mar 2, 2016
Messages
57
Location
PREVESSIN France
Aircraft
autogire
Total Flight Time
350
Hello Bartek
This photo is my blade profile. I bought them in France from AIRCOPTER. It's the same as yours. AIRCOPTER also sells the special profile to fix and screw the blade with the blade holder, its length is 300mm, the same length as the insert.


To balance the blades:
it is necessary that the finished blades are of the same weight,
if the blade profiles have a difference in weight you can correct by adjusting with the 8mm steel bar before gluing, (up to 20 gr difference)

IMG_4871.JPGIMG_4870.JPGIMG_4868.JPG
IMG_4872.JPG


The closing plates of the ends of the blades
 
Last edited:

Bartek

Newbie
Joined
Feb 10, 2021
Messages
7
Location
Poland Warsaw
Hello Bartek
This photo is my blade profile. I bought them in France from AIRCOPTER. It's the same as yours. AIRCOPTER also sells the special profile to fix and screw the blade with the blade holder, its length is 300mm, the same length as the insert.


To balance the blades:
it is necessary that the finished blades are of the same weight,
if the blade profiles have a difference in weight you can correct by adjusting with the 8mm steel bar before gluing, (up to 20 gr difference)
Thanks a lot. I have blade holder the same as you ad closing plates. I only don't have this element witch is inside the blade but i think it is easy to make it myself.
 

René

Active Member
Joined
Mar 2, 2016
Messages
57
Location
PREVESSIN France
Aircraft
autogire
Total Flight Time
350
I tried to describe to you the procedure for the manufacture of the blades of autogyro.
I used the google translation !!!!!!!


Manufacturing process of extruded blades for Gyroplane
Preparation
Pair the blades
Measure the twist of each blade and make the choice, the pair of blades must have the same twist. Maximum tolerance + XXX and - XXX.
Proceed as follows:
Weigh the weight of each blade. Maximum tolerance 20 grams for pairing.
Be careful to put the scale in the middle of the blade.
Saw the blades
Saw the exact blade length 1) 4000 mm, blade 2) 4000 mm with a fine-toothed saw.
Define the center of gravity of each blade
Take the heaviest blade as a reference.
Define its X and Y center of gravity using the triangle, mark with a felt-tip pen.
Mark with an erasable felt-tip pen on the blade a line from the outer end of the blade 1500mm above the extruded 12mm hole.
Mark with an erasable felt-tip pen on the blade a line from the outer end 2200mm above the 8mm extruded hole.
Proceed in the same way with the lightest blade.
Add on the lightest blade the difference in weight in grams with the heaviest using washers, distributing them between the 1,500 and 2,300mm points as needed to maintain the balance of the blade. The centers of gravity must be strictly identical between the two blades

Collage
Preparation of bars
heaviest blade:
Cut a bar of diam. 12 mm to 1,500 mm in length. Steel bar
Cut a bar of diam. 8mm to 2,200mm in length. Steel bar
lightest blade
Cut a bar from 12mm to 1,500mm + the length equivalent to the weight of the washers reported in mm of bar length.
Cut an 8mm bar at 2200mm + the length equivalent to the weight of the washers reported in mm of bar length.
Tapping
Tapping the entrances of the extruded holes at both ends of the blades with M10x1.75 and M14x1.5 thread length 20 mm
Inserts
For each blade proceed in the same way.
Clean the entering parts of the blades with acetone.
Prepare araldite 2011 50ml, acetone cleaner, a cloth, a syringe.
Place the same amount of araldite in the two blades at the entrance of the bars in holes 12 and 8 using the syringe.
Make the bars enter by turning them and putting glue along the bars during penetration. To distribute it well around the bars
Glue the inserts in the holes provided. The insert at the inner end to allow the blades to be tightened in the rotor head,
Heat the parts according to the table given by araldite either: 10 hours at 23 °, 45 min at 60 °, 7 min at 100 °.
Check and adjust the masses and centers of gravity of the blades

Drilling of the blade fixing holes on the blade holder
Inner blade
Fit the wedging profile in the drilling jig.
Secure the blade in the drilling template by pressing it against the outer end.
Gradually tighten the drilling jig and wedge the end of the blade with the cover at the end of the drilling jig.
Put the 9.6mm diameter guide and drill with a 9.5mm drill bit. These are the only through holes.
Change the guide to 10mm diameter to widen the hole with a 9.9mm drill bit.
Drill the other holes
Make a chamfer with the drill.
Remove burrs from each end of the hole.
Outer blade
Same procedure for all holes on the blades.
Use screws _ _ _ _ _ _

Final preparation
Balancing the rotor assembly
Fit and screw the blades onto the blade holder.
Screw the closing plates of the blades
Suspend the blade holder in balance using washers on the rising end.
Transfer the weight of the washers to the inside of the blade tip shim.
Glue the balancing screws with loctite.
Storage
Number the rooms.
Record the numbers in the logbook.
Pack the blades and the blade holder.
 

Bartek

Newbie
Joined
Feb 10, 2021
Messages
7
Location
Poland Warsaw
I tried to describe to you the procedure for the manufacture of the blades of autogyro.
I used the google translation !!!!!!!


Manufacturing process of extruded blades for Gyroplane
Preparation
Pair the blades
Measure the twist of each blade and make the choice, the pair of blades must have the same twist. Maximum tolerance + XXX and - XXX.
Proceed as follows:
Weigh the weight of each blade. Maximum tolerance 20 grams for pairing.
Be careful to put the scale in the middle of the blade.
Saw the blades
Saw the exact blade length 1) 4000 mm, blade 2) 4000 mm with a fine-toothed saw.
Define the center of gravity of each blade
Take the heaviest blade as a reference.
Define its X and Y center of gravity using the triangle, mark with a felt-tip pen.
Mark with an erasable felt-tip pen on the blade a line from the outer end of the blade 1500mm above the extruded 12mm hole.
Mark with an erasable felt-tip pen on the blade a line from the outer end 2200mm above the 8mm extruded hole.
Proceed in the same way with the lightest blade.
Add on the lightest blade the difference in weight in grams with the heaviest using washers, distributing them between the 1,500 and 2,300mm points as needed to maintain the balance of the blade. The centers of gravity must be strictly identical between the two blades

Collage
Preparation of bars
heaviest blade:
Cut a bar of diam. 12 mm to 1,500 mm in length. Steel bar
Cut a bar of diam. 8mm to 2,200mm in length. Steel bar
lightest blade
Cut a bar from 12mm to 1,500mm + the length equivalent to the weight of the washers reported in mm of bar length.
Cut an 8mm bar at 2200mm + the length equivalent to the weight of the washers reported in mm of bar length.
Tapping
Tapping the entrances of the extruded holes at both ends of the blades with M10x1.75 and M14x1.5 thread length 20 mm
Inserts
For each blade proceed in the same way.
Clean the entering parts of the blades with acetone.
Prepare araldite 2011 50ml, acetone cleaner, a cloth, a syringe.
Place the same amount of araldite in the two blades at the entrance of the bars in holes 12 and 8 using the syringe.
Make the bars enter by turning them and putting glue along the bars during penetration. To distribute it well around the bars
Glue the inserts in the holes provided. The insert at the inner end to allow the blades to be tightened in the rotor head,
Heat the parts according to the table given by araldite either: 10 hours at 23 °, 45 min at 60 °, 7 min at 100 °.
Check and adjust the masses and centers of gravity of the blades

Drilling of the blade fixing holes on the blade holder
Inner blade
Fit the wedging profile in the drilling jig.
Secure the blade in the drilling template by pressing it against the outer end.
Gradually tighten the drilling jig and wedge the end of the blade with the cover at the end of the drilling jig.
Put the 9.6mm diameter guide and drill with a 9.5mm drill bit. These are the only through holes.
Change the guide to 10mm diameter to widen the hole with a 9.9mm drill bit.
Drill the other holes
Make a chamfer with the drill.
Remove burrs from each end of the hole.
Outer blade
Same procedure for all holes on the blades.
Use screws _ _ _ _ _ _

Final preparation
Balancing the rotor assembly
Fit and screw the blades onto the blade holder.
Screw the closing plates of the blades
Suspend the blade holder in balance using washers on the rising end.
Transfer the weight of the washers to the inside of the blade tip shim.
Glue the balancing screws with loctite.
Storage
Number the rooms.
Record the numbers in the logbook.
Pack the blades and the blade holder.
Thanks a lot. Now I have full information about this process. One question about blade holder. I have 5 holes in it 8mm each. In instruction you send me there is 10mm. Should I calibrate it to 10mm?
 

Resasi

Gold Supporter
Joined
Jul 2, 2007
Messages
8,230
Location
London/ Kilifi Kenya
Aircraft
Gyrs, RAF 2000/Mgni/Bnsn/Hrnet/Mrlin/Crckt/MT-03/Lyzlle AV18-A/Prdtor. Pax ArrowCopter
Total Flight Time
100+ gyro, 16,000+ other
Congratulations on your build Bartek. It looks good.
 

Bartek

Newbie
Joined
Feb 10, 2021
Messages
7
Location
Poland Warsaw
I tried to describe to you the procedure for the manufacture of the blades of autogyro.
I used the google translation !!!!!!!


Manufacturing process of extruded blades for Gyroplane
Preparation
Pair the blades
Measure the twist of each blade and make the choice, the pair of blades must have the same twist. Maximum tolerance + XXX and - XXX.
Proceed as follows:
Weigh the weight of each blade. Maximum tolerance 20 grams for pairing.
Be careful to put the scale in the middle of the blade.
Saw the blades
Saw the exact blade length 1) 4000 mm, blade 2) 4000 mm with a fine-toothed saw.
Define the center of gravity of each blade
Take the heaviest blade as a reference.
Define its X and Y center of gravity using the triangle, mark with a felt-tip pen.
Mark with an erasable felt-tip pen on the blade a line from the outer end of the blade 1500mm above the extruded 12mm hole.
Mark with an erasable felt-tip pen on the blade a line from the outer end 2200mm above the 8mm extruded hole.
Proceed in the same way with the lightest blade.
Add on the lightest blade the difference in weight in grams with the heaviest using washers, distributing them between the 1,500 and 2,300mm points as needed to maintain the balance of the blade. The centers of gravity must be strictly identical between the two blades

Collage
Preparation of bars
heaviest blade:
Cut a bar of diam. 12 mm to 1,500 mm in length. Steel bar
Cut a bar of diam. 8mm to 2,200mm in length. Steel bar
lightest blade
Cut a bar from 12mm to 1,500mm + the length equivalent to the weight of the washers reported in mm of bar length.
Cut an 8mm bar at 2200mm + the length equivalent to the weight of the washers reported in mm of bar length.
Tapping
Tapping the entrances of the extruded holes at both ends of the blades with M10x1.75 and M14x1.5 thread length 20 mm
Inserts
For each blade proceed in the same way.
Clean the entering parts of the blades with acetone.
Prepare araldite 2011 50ml, acetone cleaner, a cloth, a syringe.
Place the same amount of araldite in the two blades at the entrance of the bars in holes 12 and 8 using the syringe.
Make the bars enter by turning them and putting glue along the bars during penetration. To distribute it well around the bars
Glue the inserts in the holes provided. The insert at the inner end to allow the blades to be tightened in the rotor head,
Heat the parts according to the table given by araldite either: 10 hours at 23 °, 45 min at 60 °, 7 min at 100 °.
Check and adjust the masses and centers of gravity of the blades

Drilling of the blade fixing holes on the blade holder
Inner blade
Fit the wedging profile in the drilling jig.
Secure the blade in the drilling template by pressing it against the outer end.
Gradually tighten the drilling jig and wedge the end of the blade with the cover at the end of the drilling jig.
Put the 9.6mm diameter guide and drill with a 9.5mm drill bit. These are the only through holes.
Change the guide to 10mm diameter to widen the hole with a 9.9mm drill bit.
Drill the other holes
Make a chamfer with the drill.
Remove burrs from each end of the hole.
Outer blade
Same procedure for all holes on the blades.
Use screws _ _ _ _ _ _

Final preparation
Balancing the rotor assembly
Fit and screw the blades onto the blade holder.
Screw the closing plates of the blades
Suspend the blade holder in balance using washers on the rising end.
Transfer the weight of the washers to the inside of the blade tip shim.
Glue the balancing screws with loctite.
Storage
Number the rooms.
Record the numbers in the logbook.
Pack the blades and the blade holder.
Hallo René,

I have question about blade holder. Could you tell me what thickness of aluminum sheet and what kind of aluminium you use to holder? In Poland we have two kind of aluminium popular: EN AW 2017 (PN PA6) and EN AW 7075 (PN PA9).
Thank you in advance.
 
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