Archive for February, 2015

Microwave project managing – week 2

Manufacturing

The visit to AMAPRO on Friday was a significant success, I feel confident enough about the process that I didn’t follow up my other turret punching options.

The company is run by a man who strongly reminds me of someone I have worked for recently, and to a lesser degree an earlier boss. This simultaneously reassures me that he will do a good quality job and also terrifies me because I am where he extracts his money.

The factory floor tour was very impressive, an expansive space but very clean, no clutter. I was most interested in their three Amada turret punch machines, recent models which seemed well maintained, one was also fitted with an automated feed allowing it to run unsupervised overnight. They also had a number of press brake machines, some automated welders and a range of other standard tooling toys.

The company has two engineers that do design work, including developing their own AMAPRO products. I will probably use them to assist in shifting from my sketches to a manufacturable product.

It was rather difficult to discuss price estimates, partly because it was very early in the design process, I also got the feeling that any final quote will vary greatly based on the quantity. They also offered that pricing for preliminary design and tooling work could be based on the eventual final order, something I am wary of because I intend to get at least one other quote for the final job.

The costs looks at being above $150 but haven’t taken into account the front face. For the initial calculations I am going to assume the front will also be metal, to avoid the plastic tooling costs, and work with a chassis price of $200. This is a significant percentage of my target cost, higher than I was hoping for, but the cost structure does have the advantage of being fairly linear based on quantity. I also think I will be able to offer the choice of cheaper metals with enamel and powder coating or full stainless as the tooling is identical. There are some other options which may be able to get the eventual cost down but they come with considerably more risk.

The mechanical portion of the feasibility stage is now complete. When I get around to prototyping I will probably build the first prototype myself in the garage, then draw up a formal design and do one or two rounds of small run manufactured prototypes.

Thermal Imaging

I also spent some time investigating thermal imaging systems. I have decided on two devices to buy and investigate further, both are very different.

The first is the Seek Thermal camera. This is a phone attachment which retails for $250 US, the latest after a series of Kickstarted products and an entry from FLIR. The company is interesting, the founders have a solid history in the industry, their prior company was purchased by FLIR and they recently got a healthy check after FLIR tried to attack them through the courts. The camera seems amazing, significantly better resolution than anything else on the market under $1000 and has a thermal range up to 350 ° C, many others cap out at around 100 ° C. The substantial downside is that Thermal makes their own sensor package and don’t sell it as a component, I am going to have to talk them in to changing this. It is also rather expensive.

The other is the Panasonic Grid-Eye 8×8, a component which provides a 64 pixel array of temperature. The main advantage is that it is price competitive, $39 USD in single unit quantities, the evaluation board is only $75 USD. The disadvantages are substantial, the resolution is poor and the temperature range caps out at 100 ° C. However while the picture won’t be nearly as good to look at compared to the Seek Thermal I think the resolution will be enough for the functionality I envisage and target temperatures tend to be under 100 ° C.

Worth mentioning is the MLX90620, my third option. This was used by the IR-Blue project, one of the early Kickstarted infrared phone products. The sensor produces a 16×4 pixel array with a temperature range up to 300 ° C. However at $87 USD per unit it sits in an uncomfortable space between the two other products, better than the Grid-Eye but nowhere near as good as the Seek Thermal. I may revisit it if the other two don’t work out.

Display

I was hoping to find one or two options for the display this week but didn’t get around to it.

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Microwave project managing – week 1

Mechanicals

So the last week has been spent dominated by getting my head around mechanicals.

I had fantastic visits to three metal stamping manufacturers, Diver, IXL and Component Industries. All three were helpful well beyond expectations, especially since they realised very quickly that I wouldn’t be able to use them.

I understood that metal stamping had upfront costs which were offset by the reduced unit costs. What I didn’t understand was the scale that they work at. Stamping is good once you want 10,000 of something and really sweet once you add another zero to that number. My preliminary working number is 500, so I have to use different techniques.

The lower cost method is a combination of turret punching, laser cutting and folding. I have actually played with similar techniques in a metal sculpture course I did a few months ago, I just didn’t think they would come into play for this kind of product. I have visited a laser cutter, Beyond Laser who promised that if I could draw it, he could cut it. I also have a visit lined up with AMAPRO and Conomatic for Friday.

It looks like what I am after is possible. I should have a much better idea on Friday but it seems like I am looking at $100-$150 for the mechanicals. This will involve more labour than the stamping technique and it may be worth looking overseas to reduce the costs.

There are also some significant unknowns with the mechanical design that impact the cost, such as what happens if you put sharp corners in the microwave chamber.

Inverters

The other main task was looking in to using inverter technology. This was less fun. Basically the technique is tied up with patents, primarily held by Panasonic. The non-Panasonic inverter microwaves seem to be either licenced or rebadged Panasonics.

Being able to buy the Panasonic guts would actually be ideal for me and seems like fairly standard practice in the industry. Figuring out who to approach is not easy though, I have sent one email off and will see if it leads to a way in.

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