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Guy Marsden

I am semi-retired as of 2022 and will only be taking on simple projects at my discretion.  You are welcome to call or email me to request that I review your potential project.

I am an independent product designer and this allows me to give you my undivided attention.  I respond quickly to email and phone calls and work efficiently.  Most jobs are completed in a few weeks.  I specialize in developing and prototyping electronic products for individual inventors and small companies.  I will be happy to discuss your idea with you at no charge for up to 15 minutes.  You may call me between 9:00am and 8:00pm Eastern US time (I am in Maine).  email me:

I enjoy learning about new product ideas and look forward to the possibility of working with you.

Here is an overview of how an average project proceeds:

1. You sign a Non Disclosure Form with me - or you have already filed a patent, or have a patent granted.
2. You call me and describe the details of your idea so I can ascertain if it falls within my skill set.  At this point I may offer an number of suggestions based on the realities of engineering.
3. You email me the detailed specifications including any drawings or diagrams (napkin sketches are fine).  This email becomes the de-facto contract that defines your expectations.
4. I provide you with an estimate to complete a first working prototype. Note!  I can NOT provide any estimate without full and complete details - every job is different.  Also my estimates are not fixed bids and the final amount may be more or less than the estimate depending on how the job goes.  I will keep you advised of any significant issues that may affect costs.
5. If you approve the estimate, I send you an invoice for 50% of the estimated amount by PayPal - allowing you to pay with debit or credit.
6. I begin work on receipt of your payment and provide detailed progress reports as the work proceeds
that include schematics, CAD files, images and video.  Most jobs take me 2 to 5 weeks.  Click here to see a blog post describing how I design a product from start to finish.
7. I document the final project for you and demonstrate it via images, video or Skype and request the final payment prior to shipping the prototype to you.

At this point you will have a proof of concept prototype that may or may not be manufacturable depending on your goals and budget limitations.  You may then hire me to do a final production design revision and prepare a bill of materials and production CAD files necessary to get bids for manufacturing.  I can also provide contract manufacturing services for small runs.

Be advised that I can NOT design smart phones or other highly complex miniature electronic products with graphic screens or keyboards.  These products require the full resources of a major corporation to develop and cost millions of dollars and many months of work by an engineering team to design.  I also don't develop products that interface with smart phones by WiFi or USB.

I work collaboratively with my associate: Justin Aiello of Aiello Design.  Justin is an experienced product designer who can design the housing for your product in 3D CAD and show you a rendering before creating a 3D prototype in plastic.  He can also guide you through the steps to get your product manufactured in the US or offshore.

NiteChest - is a lighted bedside organizer
Arclite - remote controlled barge navigation light
Nervana  - synchronizes nerve stimulation with sound to create relaxation
SAMI - Prototype for Safety Automated Monitoring Instrument for remote high pressure pipelines.
Medsonix - I designed and contract manufacture a timer for a pain treatment system
Spotter Buddy - I designed the original prototypes for this trucking industry safety product.

Below are a couple of articles that I wrote about my businesses and how I got started.

"Get rich slow, plod your way to prosperity", Inventor's Digest, April 2011
"Less Can Be More", Inventor's Digest, Oct.-Dec. 2004

TIME QUALITY PRICE - You can only have 2!

Some Testimonials

"I cannot stress enough the gratitude I have for your attention to detail, professionalism and devotion to this project. The workmanship is truly second to none and I look forward to developing this product through to production."
Ben Mulloy, private inventor

"I really am pleased with our dialogue, you seem to understand what I am talking about when I write or ask a question (although maybe I am not sure myself), and you are patient in explaining it to me."
Stephen Dawson, Inventor, Washington

"I am very impressed about the final product prototype. It look more better and beyond my expectation.  I saw your fine touch and hard work which make me more attached to continue dealing with you."
Abdullah alRasheed, Pediatric Neurosurgeon, Saudi Arabia

"Both Lauren and I want to commend you on the quality of the work that you put into the prototype. We were impressed with the appearance as well as the ease by which we could utilize the various aspects inherent in the prototype. In addition, we appreciate the effort that you put forth to complete the prototype as quickly as you were able to."
Gayle Stroh and Lauren Rosen, Astro-2000 Inc., Michigan

"I think you've done an excellent job in understanding the project and in bringing it to life.  I can't tell you what a pleasure it has been working with you - it is soooooo refreshing to do business with an honest person."  
Diane R., Inventor, Ohio

"The mechanism you built is really excellent and I must send you my congratulations for having grasped the whole idea so lightningly fast, and for putting it together with such expertise."
Gerard Sunnen, M.D.  President, Ozonics International, LLC, New York

"(The prototype) is cosmetically beyond my dreams. When we go to manufacture it, we will not change a thing. Just tell them to build it like it is. Prototypes never look like this. Excellent job."
John Fantuzzo, IRC Surplus, Texas

"I am a physicist who had a dangerous, and ugly working prototype that I wanted to step up to the next level. I contacted Guy because I liked the philosophy he presented on his website and could not have been happier with my decision.
My project involved something that Guy had little experience with, but Guy immediately immersed himself in my project and quickly became an expert. He is an excellent communicator and we had many discussions about what our goals were, and what the best way to achieve those goals would be. He sent progress reports with images and videos and was very transparent with his billing transactions. I love the product he created for me and will contact him in the future for all of my prototyping needs. Two thumbs up.
Scott H. Physics PhD Candidate, Yale University

"Thank you so much for the excellent job you did with our prototype. Your design exceeded our expectations. I was most personally impressed by:
    ● The way that you were able to take our rough concept, improve it and convert it into a fully – functional prototype.
    ● Your ability to meet a very tight deadline, without having to compromise on quality.
    ● Your frequent progress reports, drawings and photographs.
We really appreciated your flexibility in accommodating our out–of–hours telephone conference calls and Skype discussions. I have no hesitation in recommending you to others."
Dr. Mark E. Milburn,Gen. manager, Implemented Solutions, LLC, Las Vegas

"I had an idea a couple of months ago for an invention I thought might be worth pursuing. I had the idea, but that was about it. I was otherwise clueless as to how the process of going from napkin sketch to prototype actually worked, or what was involved in design and production. Following many internet searches, I found Guy Marsden’s website, and I decided not to give up - here was a human (not a faceless corporation) who could help me with the process!  From the initial conversations on, Guy was generous with his in-depth knowledge of the prototyping process, and (thankfully) was willing to work with me, a complete novice.  He answered my questions honestly, pointed me in the right direction for more information, had some great recommendations for next steps and collaborators for design work – in short, I could not have asked for a better mentor through the process of prototyping my invention. I feel incredibly lucky to have worked with Guy on this project, and will look forward to reaching out to him for future ideas. He is an extraordinarily talented artist, creator, and problem-solver who was able to make my abstract idea into a reality, and a working prototype that I am incredibly happy with."
Marguerite Swallow, private inventor


   Is your idea protected?
If you do not have a patent or one pending, you must sign a non-disclosure agreement before sharing your idea with ANYONE, including me!

   Do you have a Non Disclosure Agreement?
This document protects your disclosed information.  Click here to get my standard 2 page form in pdf format.  It is pre signed by me so you can print this form, fill it in and sign it then fax, scan and email, or mail it to me.  Please do not send me a photo of your signed copy taken with a smart phone. The agreement becomes legally binding once both parties have signed it and have copies in hand.  A number of variations of these forms are also available at office supply stores.

   Do I need a prototype in order to file a patent?
The USPTO has not required a working prototype for over a hundred years!  However the value of a working prototype is that it validates the concept and is an essential tool for marketing presentations.  It also gives you the peace of mind that you do in fact have a viable working device.  You may also find that you learn a lot from having a real device to test.  And I can often offer improvements that may add value or patentable features.

   What are the claims of your patent or idea?
What makes your idea unique and different from all others.  This will help you formulate you patent, and marketing strategy.

   Have you done a patent search?
This is the quickest way to find out if your idea has been patented already.  You can do a basic search by yourself, or hire a patent attorney to do this for you.  Choosing appropriate search terms is the key to accurate patent searches!  Try using Google Patent Search, or Free patents online:
Google patent searchfree patents online

I also encourage you to search the web for similar products.  Several of my prospective clients have been disappointed to discover that their idea was already on the market.  Google has a  Product Search feature that you can use to see if a similar product to yours is already on the market.  Searching Amazon will yield reviews of products that may be similar to your idea.  You can learn a lot from these reviews and design your product to address the negative issues found in these reviews.

   Do I need a Patent Attorney?
Absolutely.  it is one thing to do your basic patent search by yourself, but is a completely different thing to do a full patentability search for your idea.  A patent attorney has the requisite skills to determine whether or not you have a patentable idea.  You will also need a patent attorney in order to file a provisional or a full utility patent.  I can highly recommend Stevan Lieberman of Greenberg and Lieberman, this Washington-based legal firm is located very close to the patent office and they specialize in  providing affordable services for independent inventors and small companies.  You can call Stevan on his direct line anytime from 10 AM until early evening Washington time: 202-625-7016, please tell him that I referred you.  He can do a basic screening patent search for under $500, but a full patentability search will be substantially more expensive.  Representative costs for a provisional patent filing range from $5-$7000, and a simple utility patent filing ranges from $7-$10,000, your actual costs may vary depending on your specific details.

   Why file a patent?
In 2011 the United States changed the "First-to-Conceive" rule, to "First-to-File". Now, like the rest of the world, inventors will be required to file a patent to establish precedent.  Patents expire 20 years after they were filed to give the inventor plenty of time to profit from his invention.

Before filing a patent, it is wise to pay a professional patent attorney to do a patent search to determine whether or not your idea is sufficiently unique to warrant the expense of filing for a full patent.  When researching patent attorneys it is wise to ask questions about the fields that they specialize in.  For instance a patent firm that specializes in software might not be the best firm to work with for an electronic product.

The quickest and most cost-effective patent is a Provisional Patent. This secures the invention idea as yours, and establishes a filing date.  This allows you to legally claim Patent Pending and gives you one year to file for full patent protection.  Typically this should be filed right after confirming that a patent search confirms that your idea has not been patented by someone else.  A little known trick is that you can re-file the Provisional Patent before the first one lapses to give you more time if needed while maintaining the Patent Pending status, but every time your re-file your date of filing is changed.

A patent attorney charges from around $600 (for a simple design patent) to well over $10,000 (utility patent), and a utility patent can take several years to be granted.  I would only recommend pursuing a utility patent if your idea has a very broad market appeal or potential profits of at least $30,000 in the first year.  A design patent only protects what your product looks like, while a utility patent protects how it works in detail. 

You need to be realistic about the value and expense of filing a patent!  Say your patent costs you $15,000 and you sell 10,000 units in your first year.  If you amortize the cost of the patent over the product run, that means that for each product you sell, it cost you $1.50 to file the patent.  With an inexpensive product, that can make a huge difference.  In the toy industry for instance, every component is made as cheaply as possible, and shaving one cent off the price of a part can reap an extra $10,000 profit on a run of one million toys.  If you licensed the design, you will only get a very small percentage of the profit, which may never pay for the cost of the patent if the product fails in the marketplace.

Once you have a patent there is no guarantee that you will profit from it, marketing your idea is entirely up to you!  This is where most inventors drop the ball.  Fact: less than 1% of patents filed by individuals get to market. 

If a company infringes your patent (produces a product without your permission) it will cost you a lot of money in legal fees to defend your patent.  Again there is no guarantee that you will win the suit and get a settlement - even after years of legal battles!  Read the story of Gordon Gould who invented the laser and his 30 year legal battle to prove that he was the first to invent it.

Even if you obtain a patent and manage to manufacture your product, if it is not marketed properly you could be stuck with a garage or warehouse full of product.  Typically inventors are not good at marketing and often the best option is to license your product to a manufacturer who will pay you royalties on each unit sold.

   Licencing and funding your idea
To learn more about licensing and how you go about getting investors to fund your idea, I highly recommend watching the TV show "
Shark Tank".  This reality show pits people with small or growing companies against 5 wealthy self-made investors that compete to offer you financing using their own money for a share of your company.  If they don't think the product or company will be profitable, they can be unmerciful in their criticism.  They can also offer really good business advice.  Watch some old episodes of Shark Tank on the web - it's a free education, and very entertaining!

Another way to fund your idea is through crowd funding web sites such as kickstarter or indiegogo.  These web sites allow you to get multiple individuals to sponsor your startup, and in return you offer them incentives ranging from a discounted product to t-shirts and other promotional items.  You will need a documented working prototype before taking this approach as you would when seeking investors of any kind.

   What are you looking for from the Prototype?
In electronic prototypes there are basically 2 types:
Works like: Performs the functions but does not necessarily look like the final product.
Looks like: Has the appearance of the final product, but may not operate or have full functionality.  My goal as an engineer with an arts degree is to try and balance the two.

   Do you need a high quality plastic model?
I work collaboratively with Justin Aielllo of
Aiello Design on the design of products that require plastic housings.  His design aestheic is impressive and he is a great guy to work with.

   Will the prototype be used to gain funding or sell the idea to a manufacturer?
If so, a very good quality model will be required that most accurately represents the desired form and function of the manufactured item (see above).

   Will the prototype be used to test market the idea?
I can hand build up to 10 working models for beta testing and market research, but be advised that this can be expensive.

   Will the working prototype be a manufacturable design?
It depends.  High volume off-shore product assembly companies often use different electronic components than those available to me as a prototype engineer.  I can design for production in some cases, but a first step requires at least one working prototype for testing and debugging.  A second design revision phase is often required to complete a pre-production design.  Click here to see a blog post describing how I design a product from start to finish.

   Why Arduino prototypes are not helpful
Recently many of my potential clients have been using the hobby microcontroller called the "Arduino" to build proof of concept prototypes of their ideas.  It is not practical to take a design built around the Arduino and then make a production worthy electronics package based on it.  It is akin to building a prototype using LEGO and expecting an engineer to take it to production.  While the Arduino is a fun hobby computer to play with, please do not expect me to take one of your designs and make it manufacturable, it will need to be completely re-engineered.

   A word about batteries
Most of the products that I design are battery powered, and many of my clients do not necessarily understand the limitations of batteries.  Basically, there are two ways to go - replaceable coin, AA or AAA alkalines, or rechargeable such as an or iPad or smart phone that charges from a USB connection.   When you design a product with replaceable batteries, you are passing off the cost of the batteries to your customer (batteries not included).  When you make it rechargeable you are bearing the cost of a more expensive battery, the charging circuit, and the charging adapter.  Most customers prefer the convenience of a rechargeable battery.

   Be realistic about battery life.  The size of a battery gives you a good indication of how long it will power something.  If your device has a radio receiver in it, you cannot use a coin sized battery and expect it to last more than a few days because the radio receiver draws power all the time waiting for a signal.  This is why cell phones need to be recharged every day.  Also, do not expect a coin battery to keep an LED indicator light on for very long.  Even the largest coin batteries will only operate a single bright LED for no more than 10-20 hours.

   Consider the environmental impact of your product.  All rechargeable batteries contain toxic chemicals including lithium, cadmium, or lead.  These products do not belong in the landfill.  it is my personal opinion that there are far too many disposable products designed using toxic battery chemistries. Only 8% of all rechargeable batteries are recycled, and this is of great concern to me as someone who chooses to live as sustainably as practical.  You find a battery recycling location near you you can go to

   Marketing your idea
Marketing is the single biggest hurdle that individual inventors encounter.  You may wish to contact a company that can help you market your product to manufacturers.  I can recommend America Invents.  They have a good track record of licensing products to manufacturers for their clients.  As with all invention Marketing companies, be very careful to read and review their contract and hold them to every detail.  While America Invents is legitimate, there are many very unscrupulous companies out there that will charge a lot of money and deliver little or nothing.

If your invention fits a small niche market and is simple and easy enough for you to build yourself, you can set up to make it in your garage or basement and make a little money on the side while you keep your day job.  I have helped several independent inventors set up a home workshop to produce their inventions at home.  I suggest tools and techniques and provide training in soldering and fabrication techniques.  I also provide a detailed Bill Of Materials so my clients can source all the parts themselves.

I wrote an article for Inventor's Digest about a product I sell by mail order from my web site that has generated over $5,000 in annual sales since 2003.  In 2006 I introduced another product line targeting the solar heating industry that is also doing over $9,000 in annual sales.  Neither product is patented - nor are they patentable, but that has not stopped me from making money.

   Don't be seduced by potential profits
I have worked with literally hundreds of independent inventors, and to my knowledge not one of them has become wealthy from his invention, and only a tiny percentage have even gotten their design to market.  Some of them have made a nice profit, but often after many years of hard work.  It is also important to weigh the costs of patenting against the potential revenue.  It can take years and a great deal of money to obtain a patent.  It can be many more years after a product goes to market before you recover the design and patenting fees. 

   Help and advice
This process can be very daunting!  I recommend you check out Jack Lander "the Inventor Mentor" who offers affordable professional advice to inventors for a very reasonable fee.  His web page has many clear answers to questions about the patent process.  He also sells 2 books that he wrote on marketing and financing your ideas.

Some images of prototypes:

Motorcycle tachometer Motorcycle tachometer PCB      Specialised timer  Timer - battery compartment
Pill cap medication timerPill cap medication timer - electronics Alarm clock with sound player     Cutsom timer
Alarm clock with programed sounds    Alarm clock with programmed sounds Tennis scorer watch prototype  Tennis scorer watch electronics
  Nervana product      Nervana electronics Alarm system box Alarm system box inside

"We make a living by what we  get,
we make a life by what we give."
Winston Churchill

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