'Trust us, YOUR manufacturing experts'

Project Case Study



Solar Bulkhead

To design and manufacture a new injection moulded bulkhead was top of our priority list. Our goal at the beginning of 2016 was to increase the variety of products we manufacture and stock in house.

The Customer is Key

For this project, generating concepts and product ideas was an organic process but with our customers influence at the forefront. The close relationships we have with our customer base meant we had a good idea of the style of product we wanted to manufacture, in advance of the concept process.


We felt it was absolutely essential that the first step was to conduct an up to date and an in-depth customer market research with our customers and to discuss our proposed enclosure ideas. Trends change, especially in lighting so, it was important we had the confidence in the concept, before unnecessarily investing time and money.



The Challenge


Once we had established the type 0f product we would be looking to manufacture, it was time to get creative!  We hosted a variety of in-house design meetings to generate ideas and concepts, review the competition, and discuss anything which could influence the project. No idea is a bad idea, and brainstorming plays an essential role when looking at new designs. Generating idea's became an obsession for us, with out of hours meetings down the pub playing a crucial role in the final design! It is amazing what ideas spring to mind when you are at your most relaxed. It is often in these less formal settings that we get to tap into the knowledge of our design team and  Technical Consultants, and first generation of the family business, Dr Mike Pennington Ridge.  It is a privilege we are able to draw on over 55 years of mechanical engineering and moulding experience and we can not over emphasize the value we get from these meetings.


The design process is a measured process., and unfortunately we have seen first-hand the mistakes people have made when going full steam ahead, Tooling is a costly investment, and it is essential the design is suitable before any metal is cut and large costs have been incurred.

How do we make this compatible for LED?

What material shall we use?





What is our target cost?

Do we fully manufacture in plastic?

Do we fully manufacture in plastic?

Can we reduce the lamp image?


Is this concept easy to install?

How can we make this easy to assemble?


Desired Outcomes

After collating all the ideas, we had generated, the next step was to outline the features we thought were key to the project, which in turn would form the foundations of our design.  The task then became simple, we needed to design a product which we felt ticked all boxes! The process gives us the best possible opportunity of achieving our goals and provides us with valued structure. These features included:


    The bulkhead was to be manufactured in-house with our standard polycarbonate


    The bulkhead needed to be IP65


    The bulkhead needed to be IK10


    We decided we wanted to utilize our existing Lune gear tray


    The bulkhead needed to be more decorative than its competitors


    We wanted the fitting to offer the option of a halo effect to throw light against the wall


    The fitting would allow the ability to metalize the bezel, to rival the Horizon on style options


    The size of the fitting needed to be between 300 / 400mm in diameter


     Secure fixing points were desirable as this could make the luminaire anti-tamper


     We wanted the fitting to allow for a conduit entry point if possible


Budget Considerations


Additional tabs added to secure diffuser

Of course, the investment for tooling is often a significant one!  Which helped raised the question,

"could we utilize any of our existing products or tooling for this design"? If we were able to use one of our existing components, this could help significantly reduce our tooling outlay and enable us to invest that money into other areas of the project.


After more brainstorming sessions, we identified our Galaxy 325 and Dart Round diffuser's as

potential options for the new bulkhead, as they both of these the bill on size. It was when evaluating

our desired outcomes that we concluded the Dart Round diffuser was going to

be the most suited for our new bulkhead. The reasons included:


    The Dart Diffuser has a larger bottom lip which would ensure a cleaner contact for our gasket to

     ensure an IP65 rating


     It has a thicker wall section than the Galaxy, which would increase its impact resistance for

     achieving the IK10 rating,


     The diffuser has the best performance within our range at eradicating the hots spots caused by the

     LED's and aesthetically looks far superior.


     The diffuser is gated at the side which means there is no sprue witness in the centre.


The one thing missing from the Dart Diffuser was the ability to secure this to the base with screws. This meant we would need to add tabs (pictured left) to the existing diffuser without compromising the original Dart design.  A consultation with our toolmaker, quickly confirmed that we would be able to add inserts into to the tool which would enable us to mould both versions of the diffuser.

Throughout the design process and through to manufacturing, cost implication are key and must be taken into consideration so as to avoid disastrous unnecessary expenditure. No foresight at the design stage of how a product can be manufactured, and the cost implications, can be disastrous.  It can often feel like a balancing act, and although risk is an inevitability, a good understanding of manufacturing techniques and their cost implications ensure that the risk is low and calculated.


With the Solar, we knew that we wanted to injection mould the product in house, and with that inevitably comes the tooling cost. The principle of injection moulding as a manufacturing method is relatively simple. A large initial investment on tooling results in a much lower component cost to be benefited over time, especially on larger production runs.  It provides consistency, the ability to manufacture in a variety of grades to suit application requirements and is a low-cost option when compared to a metal solution.

The Design

Now that we had all thoughts and ideas in place, it was time to communicate this with our design consultants. We work closely with a range of consultants to help bring projects into life and meet budgetary and performance requirements.  This process is often 'horses for courses', and the consultants we use will depend on the complexity of the design and budgets restrictions.  These can range from low cost basic CAD drawings (which is most often all that is required) through to full product design and consultation.  For our project, we chose a consultant we knew would help us achieve the desired decorative look we were striving for.  They have vast amounts of experience within the commercial sector with aesthetics being at the forefront of their thinking.  Our expertise in lighting and manufacturing, combined with their creative influence was an ideal combination to ensure our bulkhead stood out from the crowd.

Can you guess which design we chose?

Concept Evaluation

Once the consultants had all our requirements and ideas, they went away to work their magic and came up with a range of concepts for us to evaluate. Concepts, form an important part of the design stage and no idea should be instantly dismissed. It may have real value which could go unnoticed or missed.  Once we received the designs we were then able to assess our options. On the right-hand side is an image of the bezel design concepts and below is a sideshow of functionality options, including comments.


Prototyping a product before signing off on any final designs can help eradicate mistakes which could have huge cost implications. Making modifications on tooling can be costly process and prototyping can help avoid the issue.  It also enables you to evaluate the product and make tweeks / improvements if required.  Digital drawings and renderings are great, but there is nothing quite like having the product in your hand!


There are a variety of methods used for prototyping, and their suitability is dependent on the product.  We have a 3D printer in house which enables us to manufacture prototype parts up to 200x200mm.  Our bulkhead is larger than our printer's capability, but we were able to manufacture a small version to view and use during design meetings.  This also proved to be a useful tool when speaking to customers and obtaining feedback halfway through the process.

3D Printed Prototype

For the bulkhead, we had this outsourced and machined to give us an accurate

representation of our design. This was essential for our project as it enabled us to

perform in house tests, including IP and IK.  Pictured left is an image of the prototype,

including some notes we made after our review, One consideration, was to adjust the

curved ridges on the edge of the base which were designed to act as a guide when

twisting on the decorative bezel.


We really liked this feature and thought it worked well. Our design consultants however

wanted to explore an alternative solution to avoid the risk of people trying to twist the

bezel the wrong way.  An alternative ridge was quickly drawn up and 3D sample printed

for testing. The initial results were positive, until we decided to make up the unit complete

with the gear tray! It was then discovered that the new ledge, would clash with the hinged

gear tray (pictured right), which would cause problems for the installer. Either way, we were

happy to exhaust this option to ensure the correct outcome.

Machined Prototype

Alternative Ridge

Final Outcome

Once we had signed off the drawings and authorised the production of the tooling, we had a

nervy/exciting 12 week wait. The measures we took meant that we were confidant in the final design, but it always seems like a lifetime while you wait!


Once we received the tools, we were able to go straight into production for sampling. Our Production Manager Chris, has 30 years experience processing polycarbonate so everything went very smoothly and we were very pleased with the results. This meant we were now able to send the product straight off to the LIA for testing to confirm the IP and IK ratings.


Here at Penhale Quantock Ltd we have 100% confidence in our processes and are looking forward to our next challenge!


To view the product page for the Solar click the link below:

Solar White



Units 13-15 Roughmoor Enterprise Centre,




TA4 4AT.

Tel: 01984 632090

Fax: 01984 632129

Email: sales@penhalequantock.co.uk



Galaxy Range

Isis / Isis Cast


Lune / Eclipse

Dart Square

Dart Round



Quick Links:

PQ Privacy Notice