Newmarket, New Hampshire – Controllable Pitch Propeller (CPP) blade inspection is a complex task that requires some additional considerations. The best option is to inspect the propeller in-situ while everything is mounted, synced, and set at the forward pitch setting. However, due to their size and the ability to disassemble the propeller’s blades (and spares), individual CPP blades are frequently what the repair facility receives – in other words, the blades are not always accompanied by their corresponding hub. This document serves to provide guidance for TrueProp Virtual users working on individual controllable pitch propellers.

Controllable Pitch Blades 
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When capturing a single CP blade, it is very important to scan the blade palm and bolt pattern. The hub mechanism interfaces with these holes, making them critical positioning references (similar to the bore in a monoblock propeller). Always scan the root and palm. Best practices should also capture the underside of the palm, since the position of this plane determines the resulting diameter of the blade.

Blade Orientation 
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Once the blade has been captured, it must be properly positioned in XYZ space. It is easiest to start by registering an individual blade to a coordinate system first, then assembling the blades into a full propeller for inspection.
Pay careful attention to the bolt pattern. Some key aspects:
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• Keep palm/hub mechanism interfaces centered about the Y axis.

• Put the bottom of the palm plane on the XZ plane.
• Register the center of the critical bolt holes using cylindrical fits.
• Set the pitch angle orientation using the angle of the bolt holes on the palm. If there is a drawing, this angle may be explicitly defined for the design pitch.

Analysis in TrueProp
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With the assembled data fully registered, we can import the STL mesh into TrueProp. The Virtual Plugin accepts the STL mesh and extracts the radial inspection data for each blade.

​When no design data is available, TrueProp can generate a proxy design reference by averaging the profiles of the imported blades. This provides a baseline for comparing blades and determining the overall quality of the blade set (Class S, 1, 2, 3 or no class). The reference can also be saved and re-used for comparison of additional blade scans, spares, rebuilt blades, and so forth.

Newmarket, New Hampshire - Introducing TrueProp 2024, the latest advancement in propeller inspection software from TrueProp Software. Based on feedback from over 36 propeller shops worldwide, TrueProp 2024 introduces several powerful features designed to enhance efficiency and precision for our users.

​Key Features of TrueProp 2024 Include:

•      Blade Rake Utility: Estimate rake angles with precision and ease.
•      Job Attachments: Seamlessly add photos and files for comprehensive job management.
•      Enhanced Zoom and Pan Functions: Navigate Rake & Outline plots effortlessly.
•      Expanded Keyboard Shortcuts: Streamline operations with additional shortcuts.
•      International Support: Operate TrueProp in non-English environments seamlessly.
•      Direct Virtual Plugin Launch: Post-process 3D scan files directly from TrueProp.
•      Improved Guidance: Enhanced colors for easier rescan procedures.

The TrueProp 2024 upgrade is available through our Upgrade and Support program. Contact us today to upgrade your software version or explore additional technical support options, ensuring uninterrupted access to updates and personalized customer service. TrueProp Software remains committed to delivering cutting-edge solutions that redefine propeller inspection software. Join our community of TrueProp 2024 users and experience unparalleled efficiency and support.

New Hampshire-based TrueProp was formed in 2017 as an offshoot of HydroComp. Since then, the company’s specialist propeller inspection and repair software has been widely used within the industry. This software has recently been upgraded to meet the evolving requirements of shipyards and other propeller service providers, and now offers a virtual plug-in for 3D scanners.

The TrueProp core product based on inspection and repair codes with a diagnostic screen, remains the same. However, a new parallel code, that enables the software to integrate with a 3D scanner, has been introduced. The TrueProp Virtual Plug-in allows the user to extract angle-drop data automatically. This data is then analysed for class compliance with TrueProp.

This development means there is no longer a need to remove the propeller from the ship, which significantly saves on costs and time for yards. “Our aim is to allow shipyards and drydocks to inspect the propeller without the need for a specialist workshop. The link between our software and the 3D scanner means that yards can inspect even large and complex propellers, including CPP units, with a simple handheld device,” says Adam Kaplan, chief technical officer.

“As a result of this initiative, yards can save a lot of time and money as it is possible to scan the propeller without dismantling and transporting it away from the ship, and to assess if a repair is needed, and if so what type of repair is required, in situ. Consequently, the whole drydocking schedule can be significantly accelerated," adds Kaplan.

According to Kaplan, the new 3D Virtual Plug-in will allow TrueProp to target an expanded market base.“ Whereas previously customers used to have to have specialist machines, and dedicated propeller repair and service workshops, that is no longer the case. This upgrade enables our customer base to be expanded and thereby make the servicing and repair of propeller units more widely available,” he says.
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3D scanners are largely general-purpose tools and can be used for a variety of other tasks within a yard, for example in connection with the routing of piping. So, any investment in the device can be quickly paid off. Furthermore, the TrueProp 3D Virtual Plug-in can be used with a variety of commercially available scanners.

However, the company offers a hardware and software bundle that includes TrueProp Virtual and the Einscan HX from Shining 3D. This bundle allows propellers as large as 3m (120inches) to be scanned with a portable hand-held scanner. The user can enter the diameter and select the radial positions for extracting ISO 484 type data, with a process that mimics the traditional pitchometer process, etching scan lines into the captured propeller in 3D.

The TrueProp Virtual Einscan HX bundle provides fast 3D capture from 14 simultaneous blue light laser lines and its stereolithography (STL) 3D file output is considered perfect for analysis with the TrueProp Virtual edition. “Using the TrueProp Virtual Plug-in, even non-watertight STL meshes can be interrogated at the ISO 484 radial positions. This provides us with the pitch, chord lengths, blade outline and other metrics used in TrueProp’s Class reports,” says Kaplan.

TrueProp Virtual is currently being utilized by more than 30 propeller shops worldwide. The company also reports a significant amount of interest amongst larger shipyards which have traditionally outsourced both propeller inspection and repair. “We are seeing more shipyard interest and at a recent ship repair conference in New Orleans my presentation on the subject attracted a full room! I think that shows that the concept is resonating positively amongst yard operators as well as other propeller service providers," notes Kaplan.

Earlier this year TrueProp 2023 was released as the latest version of the propeller inspection software. The new features include expanded diagnostics to identify and correct damage to propellers, including evaluation of propeller blade thickness, blade areas and effective pitch. Operators can quickly determine what is wrong with a propeller and take corrective action, if necessary, the company states.
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With the 2023 version TrueProp has also introduced a new upgrade and support programme. This is claimed to provide much needed support for the propeller service industry, reducing downtime for propeller inspection devices and ensuring that technical questions are answered promptly by other knowledgeable professionals.

*This article was originally published in the July/August 2023 edition of Professional BoatBuilder Magazine​, written by Dieter Loibner.

​A high-pitch five-blade prop shows in a similar display.

During the 1990s, several providers of computerized propeller measuring devices entered this limited and specialized market. Only a few survived. “We were asked over and over to develop something for these old machines from the nineties, because the original equipment vendors went out of business,” said Adam Kaplan, CTO of TrueProp in Newmarket, New Hampshire. The firm is a spinoff from HydroComp, Inc., which develops and markets design tools for hydrodynamics and propulsion systems, including software for propeller design, sizing, and manufacturing. “People were using [these machines] but couldn’t get parts or support, [and] were running old Windows 95 computers with all this stuff.” Kaplan said HydroComp initially was contracted for the electronics integration and software development for a new scanning tool, a one-off project that morphed into the TrueProp software, which is part of an integrated solution.

A typical use of TrueProp is tracing the surface of a defective propeller with a scanner to measure blade height and angle. The program provides visual aids in the form of charts and diagrams that illustrate the tolerance (i.e., the acceptable difference between measurements), so technicians recognize what alterations are necessary to bring a damaged prop back into shape.

“Some repairs are outside the limits of what’s possible to do by moving the metal, so sometimes you need to replace things, and, in that case, the software also helps [technicians] measure and determine what they have,” Kaplan said. “There’s another aspect—performance tweaking. If you have an engine problem or speed problem with the boat, [propeller shops] can use TrueProp to make some modifications to the propeller.”
Kaplan observed that propeller designs “are becoming much more advanced and thus much harder to repair with traditional tools.” To keep pace with this evolution and the changing repair and service requirements for newer prop styles, TrueProp partners with Creaform of Lévis, Quebec, Canada, a manufacturer of portable 3D measuring equipment, and Linden Propeller of Dubuque, Iowa, makers of the hydraulic Prop Press and the Digital Data Scanner—all compatible with the TrueProp software.
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“We were an early adopter of the software but use it differently than other shops,” said Jody Bell, vice president of sales at Osborne Propellers in Langley, British Columbia, Canada, which serves workboat and leisure craft markets. “We use TrueProp more for the capture of current propeller geometry to feed into our CAD system than for repairs. We design and build propellers for commercial applications, and TrueProp is quite handy in capturing geometry that would otherwise be very hard to measure, specifically rake and skew distribution and chord lengths.” Bell said Osborne runs three different Hale MRI machines for propellers ranging in size from 50“ to 120“ (1.27m to 3.05m) diameter.

Bell commended TrueProp’s ability to customize the software to improve compatibility and workflow when using existing equipment, something he felt had been missing with other vendors in the past. “TrueProp is affiliated with HydroComp, and we use their other software packages, and they talk to one another nicely. We are able to capture design features that allow us to replicate propeller geometry quickly and easily using our existing measuring equipment.” The digital revolution made it a lot cheaper and faster to produce and share data with others in the supply chain. Osborne also relies on HydroComp’s PropCAD to produce drawings and coordinate tables for manufacturing custom propellers, and for its built-in features to calculate thicknesses and provide torsional data to engine and gear suppliers.

Asked about sending workers to shipyards to inspect and repair propellers, Bell said he prefers to work in-house, where his technicians can get better results faster than off-site. “The cost of insurance is also a factor. Adding ship repairers’ liability insurance is a huge expense, so we choose not to. I’m certain that this costs us some jobs every year, but we’re better off in the long run.” Osborne does not cast propellers and often chooses between machining in-house or through subcontractors as needed. Contracting out certain types of work, Bell explained, “allows us to scale up our capabilities without the capital expense.”
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​In some cases, heat is still applied to shape damaged propellers.

For nearly 30 years, Cool Breeze Marine of Osage Beach, Missouri, has been fixing props on the shores of the Lake of the Ozarks. Customers include local boaters with prop trouble, but the shop also works on specimens sent from other parts of the country, not just by recreational boaters but also by racers. “Manual pitch blocks, rake gauges, a good eye, and 30 years of knowledge” is what shop owner George Peter used before switching to the TrueProp software and PropExpert, a program to calculate diameter, pitch, reduction-gear ratio, and blade area when sizing propellers.

Peter’s shop, which is certified by the National Marine Propeller Association sees a diverse range of defective propellers, from trolling motors to trawlers, and from aluminum runabout props to 6-blade high-performance stainless-steel to 8-blade 40“-diameter (1m) inboard yacht propellers. “People hit rocks, logs, their own boat trailers, or dock lifts and cables,” he said. “In the rainy season, it’s mostly logs. In the dry season, it’s mostly rocks. Damage happens all year long.” Peter calls TrueProp “the most accurate system on the market today” because it eliminates guesswork. He uses a Linden Digital Data Scanner with the TrueProp software to analyze the propellers and Linden’s hydraulic Prop Press 360 to bend them back into shape.
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Not every customer checks in with prop trauma. Many ask for a propeller tune-up to improve performance. “Where the Prop Press 360 and TrueProp software really come into play is when we are doing performance modifications,” Peter said. “We can take existing specs and data off the prop, talk with the customer to see what they want their boat to do or any performance issues they’ve encountered, and we figure out what it’s going to take to change the props to make that happen. Bending the prop accordingly can save customers time and thousands of dollars, and it gives them better fuel economy and longer engine life, because the prop will be modified to help the boat perform the way it should.”
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When it comes to bent props, there are different levels of mystery, Peter intimated. If the extent of the damage is visible, the evaluation by experienced technicians is usually quick and straightforward. When a customer tells him, “We didn’t hit anything, but now the boat shakes,” the only way to see it is with a scan that shows where the bend is and where to fix it. Smaller props are put on pitch blocks and beat into shape with rawhide-faced hammers, while large propellers are put on the Prop Press to be scanned and subsequently bent back with hydraulic force until they conform to specifications. If necessary, missing metal is welded back on, followed by grinding, finishing, and balancing. “Turnaround time depends on the level of damage and the time of year the prop comes into our shop,” Peter said. “It can take anywhere from one to two days to three weeks, [but] average is about two weeks.”
As a complication, propellers continue to evolve. “Back in the day, we talked about pitch, like a propeller can be a 20“ [0.5m] pitch,” Kaplan mused. “And traditionally those 20“ props measured that same value everywhere across the prop. But designs have advanced so much now [with] a lot more curvature and variation from the leading to the trailing edge of the blade, and from the root of the blade up to the tip. So you really need a digital system that allows you to compare these blades in a meaningful way. Traditional tools don’t quite work with these newer propeller designs. People can’t just repair them like they used to. They can’t use their grandfather’s methods.”
More examples of propeller repairs can be found on TrueProp’s showcase page
TrueProp, 5 Penstock Way, Suite 101, Newmarket, NH 03857, USA, tel. 603–868–3366.

Introducing TrueProp 2023, the latest version of our next-generation propeller inspection software! Building off our progress in 2022, the latest update includes a number of great new features for our users.

Major new features released in 2023 include:

•      Improved estimation of Blade Area (BAR).
•      Click/Drag interaction with Tolerance boxes (PITCH and LOCAL PITCH).
•      Zoom and pan features on the PATH Plot.
•      Option for high/low tolerance coloring in reports.
•      Improved Save Angle tools for rescanning a radius.
•      Better alignment tools for comparing different jobs.
•      Virtual Plugin support for back/suction surface scanning.
•      Virtual Plugin support for measurement of max thickness.

With the 2023 version, we’ve also introduced our Upgrade and Support program, allowing you to upgrade your program version and get a tailored level of support to fit your business. Having access to the most robust features and personalized customer support maximizes the value of your software and ensures no interruption in receiving updates and technical support.

Isn’t it time you added TrueProp to your shop? Contact us today to get started!

Figure 3– Interactive graphs allow pan and zoom so you can see your repairs in detail.

As we get closer to celebrating the start of a New Year, we would like to reflect on some major additions to TrueProp Software. These new expansions go beyond the traditional software component and truly add new value to the TrueProp you know and love. We genuinely enjoy working with propeller shops worldwide and the insights many owners bring to our developments. 
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This revolutionary process allows general-purpose 3D scanners to be used for propeller inspection in place of a digital pitchometer! Popular with propeller manufacturers, shipyards, and port authorities, the TrueProp Virtual Plug-In represents the latest technological advances in propeller measurement technology! ​

TrueProp recently presented our upgrade kit for the Prop Scan electronics and encoders. The upgrade kit is designed for Prop Scans with damaged or failing electronics hardware. With OEM parts completely out of production, this upgrade is the best way to extend the life of your Prop Scan machine! ​

Coming in 2022...​

TrueProp's commitment to quality means that our software capabilities are continuously refined based on the valued feedback from our users!

Before we ring in the new year, we'd like to reflect on how far TrueProp has advanced in 2021. Just like everyone, we had some resolutions going into this year, and we are happy that we can check off many developments. Plus, we've had a blast working on these new features and seeing them implemented at your shop. 
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Be tempted by the Dark Side! TrueProp now supports Light, Cool, and Dark modes for easy, high-contrast viewing!
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TrueProp's leading and trailing edge filters programmatically ensure the start and stop position of the scan line is accurately captured. This allows users to focus on the work and not worry about carefully placing the probe on the propeller edge! 
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     Durham, New Hampshire - Introducing TrueProp 2021, the latest version of our next-generation propeller inspection software! All our existing customers are eligible for this complimentary software upgrade as TrueProp Software continues to add features and incorporate feedback from propeller shops all over the world. The 2021 update is feature-packed – including automatic detection of propeller blade edges, noise-filters to improve encoder signal quality, new options for visualizing graphs and reports, and so much more. 

     TrueProp guides propeller technicians through the scanning process, but also allows scanning in any direction and in any blade order. ISO-484 Class tolerances can be applied to determine both the current propeller quality and the desired propeller quality (with out-of-tolerance regions clearly identified). Technicians can access all the classic propeller visualizations – including bar graphs, top views, and individual radius scan lines.

     Expand your propeller scanning capabilities by pairing the new 2021 TrueProp Virtual Plug-In. The Virtual Plug-In enables users to process 3D scan files (in STL or OBJ format) from commercial laser scanning equipment, which means you can now inspect propellers almost anywhere – even while they are still on the boat! 
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     The Virtual Plugin extracts all the required data for an ISO-484 Class Quality analysis quickly and efficiently. Most scanners and laser scan files are suitable for virtual inspection – including incomplete scan files or files with holes. In mere minutes, the surface data is extracted from the desired radial positions and saved to a point cloud file.

In TrueProp, you import the point cloud, enter the customer information, apply your Class tolerance, and generate a compliance report.

​     TrueProp Software is transforming and accelerating the propeller industry with the next generation of propeller inspection software. Isn’t it time for you to consider adding TrueProp? Contact us today to start a discussion about adding TrueProp software.

Adam Kaplan, CTO, had the pleasure of being featured on the official podcast of the National Marine Propeller Association, Prop Talk. Take the time to give this episode a listen, and you'll be immersed in an enlightening discussion about cup, pitch, rake, camber, and technology's role in propeller design, repair, and performance analysis.

In August 2020, TrueProp Software hosted our first free public educational webinar. View all of our webinar recordings here and sign up to receive notices of upcoming presentations.

HydroComp’s Adam Kaplan comments on his close professional relationship with Ignacio: “Working with Ignacio and the team at Padgett Swan is a pleasure. We have been supporting them for many years with their use of PropCad and PropExpert. Ignacio and I work together regularly through phone, email and screen-sharing sessions. Ignacio uses almost every feature in PropCad and TrueProp – it has been a very beneficial partnership that has led to new capabilities for their company and robust software improvements for HydroComp and TrueProp.

Ignancio’s relationship with HydroComp has been a recipe of keen minds, superior tools, and the desire to continually improve and educate. When someone like Ignacio is offered continued opportunities to advance their craft, they don’t waste time. By coupling this energy with cutting edge advanced propeller tools, there are no limits to what can be accomplished.

Download the full interview here: PadgettSwannInterview.pdf


For more information, please contact:                                       ​

When repairing propellers, it’s important to review and understand the intent of the propeller’s design. Is the variation in pitch due to damage or was that the design intent? Is this propeller a traditional design, where the face of the blade is flat and the pitch is uniform across all radii? That would be a constant pitch propeller with a flat-face…  Is there more to the design? Is this propeller a contemporary design, with section pitch varying from the root to tip, like a variable pitch prop? Is there variation in the local pitch from leading edge to trailing edge, like a cambered faced/progressive pitch propeller? These are important questions to answer before you begin reworking the blades!

We wish everyone a successful 2020 and look forward to seeing all of you at the 2020 convention!

Did you enjoy this article? View PART 2 - Progressive Pitch: Performance at HydroCompInc.com!

Learn more about the propeller sizing, design, and repair tools offered by TrueProp and our sister company, HydroComp, in the November 2019 issue of Marine News!

The full article is available via MarineLink.com.
​Click here to read the full article!

​What started as a one-off software development project for a single client has grown into a company that helps propeller designers and manufacturers make better products. TrueProp was founded in 2017 as a sister company to 35-year-old HydroComp in Durham. HydroComp develops performance prediction software for naval architects and shipbuilders to aid in the design and analysis of ship hulls and propellers.​

Read the full article through Business NH Magazine!
Click here to download the article