Mechanical Update: Things Are Looking Good!

Nov 24 2018

Patient Doppler backers,

For those that had a lot of turkey the other day, how about a quick update with lots of pictures to help you digest?

As promised we said we would let you know about the newest plastic parts. Well, today is that day!!

In this shorter update, we will review the current mechanical parts in detail and show what we have improved along with what still needs to be perfected. Make sure to check the end of this update for instructions on how to grab your discounted original Sandman we mentioned in the previous update!

Here are the newest Mechanical Doppler parts:

The most recent generation of Doppler parts

Things are looking great! Details below!

In previous updates, we have gone over the process of injection molding and how this process works to get perfect plastic parts made in volume. If you'd like a refresher, check out this update, it's very informative! Well, at this point we have made 3 or 4 tool revisions on the majority of the tools and we are very happy with how most of them have turned out. Let's start with the most important part of the Doppler, the main body.

Previous revisions of the main body had some warpage in the part. This basically means that the part isn't quite as straight as it is supposed to be and isn't being molded properly on the first try. A big and complex part such as this is expected to have some warpage in the first couple revisions, so we weren't concerned as we knew that a lot of the warp could be ironed out by adjusting certain things in the tool by our overseas team. The newest parts are much less warped and look almost perfect, great job guys! So what isn't quite perfect yet? Currently, there is some extra plastic, called flash, around the microphone and speaker holes. Along with this, we noticed that the buttons sometimes stick slightly when depressed. This can be easily remedied by adjusting the tooling ever so slightly to open up the holes. Again, these types of issues are to be expected when working with new injection molding tools as the tolerances are very tight. We are hoping the next revision of the part will be production ready!

Warp on the left, almost perfect on the right

Holes with minor flash

Closeup of the flash

Very early on in the development process of the Doppler, we decided to do a special surface treatment to the exterior of the Doppler called soft touch. Soft touch is a special coating that is put on the outside of products that makes the products appear less shiny and literally soft to the touch. This process has become more and more prevalent in products in the last 10 years or so and really makes a product feel premium and high quality. Well, even though we are going to be putting soft touch coating on the majority of the exterior surfaces of the Doppler, we still wanted to make sure that underneath the coating the bare plastic was smooth, even, and not scratched. We still have a little bit of work to do on this front, but we are confident that the product will look perfect.

No soft touch on the left, soft touch on the right

The speaker frame is an integral part of the Doppler and creates an air seal to make the speakers sound as good as possible. This part hasn't changed much at all, and we are very happy with it. We do need to modify a hole slightly, which should be done in the next revision. This is considered a "tool safe" change and will be very easy to do. A quick aside on what is considered tool safe or not. At a basic level, an injection mold is a giant hunk of metal. If the required modification to the giant hunk of metal removes some metal, it's considered tool safe. If the edit you need to do on the tool requires you to add metal into the tool, this is much harder and considered not tool safe as it's much easier to cut away some metal than it is to add more metal. The change we need to do is to slightly increase the size of a hole, so this requires removing metal in the tool, so it's tool safe. The hole that we need to increase in size is the hole where the cable goes in between the button board and display board. We are increasing this hole slightly because it will make sourcing these cables much easier in production.

The speaker frame and the hole we need to increase

Closeup of the backside of the hole

The display frame is the part that actually makes the Doppler's lights come to life! Without the display frame you'd just have blobs of light without any sort of separated segments. In order to get these segments as crisp as possible, the display frame has to be as flat as possible. We noticed some rough spots on the display, in particular with the area around the temperature/humidity 7 segments. This has been smoothed out in the latest revision and looks great.

Closeup showing the rough finish

Closeup showing the smoothed out part

So, what else needs to be done? Well once these couple issues are resolved we will make 20 full sets of the parts for an engineering build. We will assemble these 20 units with circuit boards (more on that in the next update) and make 20 working Dopplers! These will be the alpha units and we will stress test them and go over everything with a fine-toothed comb. It's very likely we will find some other small issues which we will want to tackle before we move on to the larger scale beta test.

In general, we are very happy with the mechanical and we hope you all are as well!

As mentioned in our previous update, we wanted to do something for all of you for being so patient while we work through these supplier issues. We sent out the discount codes for your discounted Original Sandman the other day to the email address you used for this campaign. If you still haven't gotten it, make sure to check your spam folder, if it's still not there, let us know and we will make it right. Please send us a message or an email at support@paloaltoinnovation.com. Hopefully this discounted original Sandman holds you over until the Doppler arrives, it also makes a great gift!

We plan on sending out another update addressing the circuit boards shortly, but things are looking great. Thanks again for your patience!

-PAI team