How do I find a specific APC propeller?
The APC website has several tools to help you find specific propellers. Use the search bar at the top of the site to search for a particular product, or go to the main products page and filter results to find what you need.
Does APC only sell propellers?
Yes, we only sell propellers to both the general public and resellers. All APC propellers are manufactured in California, at the same facility as our distribution center. Although the core of our business is selling our propellers to dealers and distributors, we make all of our propellers available to the public. This is because not all hobby shops carry every propeller that we manufacture. Please contact you local hobby store for other modeling items you may need.
How do I orient ANY fixed pitch propeller on my motor?
The leading edge of the propeller blade should always point towards the direction of flight and in the direction of motor rotation. If you have trouble identifying the leading edge of your propeller, please contact us. In the case of multi-copter applications, the direction of flight is up.
How do I balance a propeller?
More information on balancing and proper installation can be found in the Technical Support Advisories section.
How do I ream an APC propeller to fit my motor shaft?
If using a tapered reamer, start from front of prop hub. A step reamer can be used from either side.
For the most accurate fit, start from the rear with a step reamer. This may be slightly more accurate since you will be indexing on the molded part of the through hole. After that, use the tapered reamer from the front to open the hole slightly without touching the aft part.
Can I use the APC Adapter Rings on gas / glow propellers?
Yes, the LPAR06E rings will work if the back side of the propeller is reamed to 3/8 of an inch (0.375). A step reamer works best.
How can I change to color of my APC propellers?
Clothing dye (RIT) can be used to change the color of APC propellers. Dark colors work best and no re-balancing is required. Using clothing dye is the best approach for changing the color of a large batch of propellers. Please use hot water and follow the dye manufacturer's instructions.
APC propellers can also be painted with hobby paint. Make sure to check the balance after painting.
What do the letters and numbers stamped on APC propellers represent?
The nomenclature used for APC propellers helps identify the size and type of each propeller.
The size of each propeller is designated by two numbers that are stamped onto the propeller blade, separated by an X. The first number represents the diameter of the propeller in inches. The second number is the pitch in inches per revolution.
APC propellers are by default assumed to be of a standard type (Sport), unless modified for a specific characteristic or purpose. Sport propellers are intended for use with internal combustion engines. The letter(s) following the propeller size indicate the type and/or modification. The various propeller types and modifiers are described as follows:
|E||Thin Electric or Electric (electric only)|
|F||Folding Blade (electric only)|
|MR||Multi-Rotor (electric only)|
|SF||Slow Flyer (electric only)|
|R||Reversible ESC (electric only)|
|B4||Bundle Pack (2CW and 2 CCW propellers)|
|NN||Very Narrow (chord)|
|P||Pusher (or reverse rotation for electrics)|
|( )||Reserved for Special Notes|
A combination of the above maybe used. For example: MRP is a reverse rotation multi-rotor propeller.
If there are no letters behind the propeller size, then it is a standard rotation Sport propeller.
Although sport propellers are intended for use with internal combustion engines, they can also be used with electric motors.
Electric propellers are intended for use with electric motors only.
Please note the recommended RPM limits for each propeller type. These limits can be found on the RPM Limits page.
A PDF document with this information is also available for download.
What is the difference between Sport and Pattern propellers?
Pattern propellers in the 18 to 21 inch diameters have wider tips to improve down line breaking and up line acceleration. These are intended to be mounted on 4-stroke engines, like the YS.
Larger sport propellers (18" and above) have narrower tips and larger hubs. The larger hubs allow this type of propeller to be mounted on engines that use a bolt pattern around the center bolt.
Smaller sport and pattern propellers use the same design approach. We have designated some of these smaller propellers as 'Pattern' because the pitch and diameter are suitable for pattern type flying (for example classic pattern). Of course, pattern propellers can also be used for sport flying.
Please see the product photos to compare the blade shapes.
Can the hub on an APC propeller be drilled for a N-bolt pattern?
Yes, our larger gas / glow engine propellers (18 inches and above) are designed to accept hole patterns for mounting on engines like the DLE and DA. Please note that the drilled holes must be at least one (1) hole diameter away from the edge of the hub.
How do I identify a matched pair of CW and CCW rotating propellers?
Matched standard and reverse rotation propellers are identified with a P at the end of the part number of one of the propellers. For example: 10x7 and 10x7P are matched pairs, and 10x7E and 10x7EP are also matched pairs. The letter P should be the only difference in the part numbers.
Can APC recommend a specific propeller for my model and engine combination?
APC does not make specific recommendations for propeller sizes.
Large variations exist in engine/motor performance characteristics and in model aircraft applications. Therefore, we are unable to reliably offer propeller size recommendations for specific combinations of motor type, size and application.
Please rely on written instructions/recommendations that are provided with most motors. If propeller size recommendations are not provided with the motor, please contact the motor manufacturer for suggestions.
Does APC make multi-rotor propellers with diameters less than 8 inches?
Yes, many APC Thin Electric propellers are also well suited for multi-rotor aircraft. CW and CCW combinations are available in 5, 6 and 7 inch diameters. Please see our Multi-Rotor product category.
Do APC multi-rotor propellers come individually packaged?
Yes, all muti-rotor propellers are also available in individual packaging. The standard rotation (MR) and reverse rotation (MRP) propellers can be purchased separately.
Why are adapter rings not included with Multi-Rotor propellers?
Adapter rings are not included in single packs only. The 4-packs of multi-rotor props do include adapter rings. Adapter rings are also available separately here.
Are the Slow Fly APC propellers suitable for multi-rotor aircraft?
Yes, our SF propellers are widely used on quad-copters and other multi-rotor aircraft. The SF type propellers are best suited for lighter copters that spend a majority of their flight in hover. They are also a great replacement for stock propellers, increasing performance, efficiency and reliability.
How do I mount my self-tightening multi-rotor propellers?
When mounting, the propeller should spin on by pushing on the leading edge of the blade. Use the inner portion of the blades to tighten the propeller, take care not to damage the blades. The left-hand threaded propeller (MRP) should mount to the clockwise rotating motor when looking at the top of the multi-copter. The right-hand threaded propeller (MR) should mount to the counter-clockwise rotating motor when looking at the top of the multi-copter. A left-hand motor shaft thread (M6-1 LH) must be used for reverse rotation (pusher) propellers. A right-hand motor shaft thread (M6-1 RH) must be used for standard rotation propellers. The motor torque will keep the propeller snug.
If your motors do not have M6-1 threaded studs, you can purchase a set of adapters. Please see the Motor Adapters section for more information.
Self tightening propellers are not recommended for systems with active breaking.
Can I replace my keyed propellers, ones with flat spots in the hub, with APC propellers?
Yes, however some modification to the propeller or motor shaft may be necessary.
If the propeller shafts on your motors are removable, they can be replaced with ones that do not have flat spots. Please see the Motor Adapters section for more information.
Alternatively, the through hole in the APC propeller can be enlarged to accommodate a shaft diameter that has flat spots. This diameter is typically 8mm. Our SF type propellers already include an 8mm diameter recess in the back side. The MR type propellers also have a feature in the back side that accepts larger adapter rings. A 5/16 inch (8mm) adapter ring is available in adapter set LPAR06E. Simply enlarge the center hole with a stepped propeller reamer. Tower Hobbies offers several reamers that will do the job. A list of part numbers can be found in the Propeller Reamers section.
What propeller combinations should I use for co-axial motor applications?
APC recommends that a larger diameter be used for the leading (upper) propeller and a higher pitch be used for the trailing (lower) propeller. For example: an 11x4.5MR for the leading blade and the 10x5.5MRP for the trailing blade. This will provide more balanced loading on the motors and make the multi-copter more efficient.
Why was the 21x14E replaced by the 21x13E propeller?
The original propeller was mislabeled. Please see more in our Technical Advisories section.
Why is the hub on my older Thin Electric propeller thinner than the one I just bought?
Starting in 2010, APC updated its line of Thin Electric propellers due to increasing motor and battery power. The new versions have a slightly thicker hub and a thicker hub-to-blade transition. This design change causes the first natural frequency of the blade to be outside of the recommended operating RPM range. The result is a more robust and quieter propeller. In higher rpm conditions, the new design is also more efficient. If you are not sure which version you have, please compare the hub thickness of your propeller to the information on our website. Only the new versions are now available.
Are older versions of the Thin Electric propellers safe to use?
Yes, when operated within the recommended RPM range.
Does APC make carbon propellers?
Yes, APC has a limited selection of injection molded carbon propellers. These propellers are made from 40% Carbon and 60% Nylon. Please see our Carbon Propeller section for available sizes.
Why does APC not make more propeller sizes from carbon material?
APC only manufactures injection molded propellers. The carbon material we use is very abrasive and causes excessive wear on our equipment, requiring parts to be replaced frequently. Due to the additional expense of manufacturing with carbon material, we only produce carbon propellers for specific applications.
Does APC make custom propellers?
Yes, custom propeller requests are welcomed and are evaluated on a case by case basis.
APC does not charge for tooling and setup costs for injection molded propellers when a minimum initial order quantity is met. The quantity of the initial order depends on the complexity of the design and the size of the propeller. Larger propellers require a smaller initial minimum quantity.
Low volume and prototype production is available.
It is possible to purchase tooling only, for hand-layup applications.
Design engineering services are also available.
Please contact us for more details at firstname.lastname@example.org.
Where can I find APC propeller performance data?
APC propeller performance data is available for all propellers currently in production. This data can be found in our Technical Info section on the Performance Data page.
What is the basis for the APC propeller performance data?
The performance data is determined analytically. More on the methods used, and our future objectives, can be found in our Engineering section.
Are sea level Standard Atmosphere conditions used in performance calculations?
Yes, the Standard Atmosphere density altitude at sea level is used to calculate the power, torque and thrust values.
Standard Atmosphere Values at Sea Level:
|Pressure||29.92 in-Hg (760 mm-Hg)|
|Specific Weight||0.076474 lb/ft^3 (1.225 kg/m^3)|
|Density||0.0023769 lb-sec^2/ft^4 (0.12492 kg-sec^2/m^4)|
Why is the actual air speed of my aircraft much higher when compared to the calculated pitch speed of the propeller?
The pitch speed of the propeller uses the measured pitch and does not account for the airfoil camber in the blade. As a result, the effective pitch of the propeller is higher than the measured pitch due to the lift generated by the cambered airfoil.