Archive | July 2012

Heater Band Evaluation

When running the heater band for the first time, we were wondering why it was taking so long to heat up and start melting the plastic. We had lots of smoke and no melting. Doing a thermal analysis of our current set up, its obvious why it takes so long.  This image is if the heater band is set to constant 500 F and nothing else acting on it. This is after ten minutes. The pineapple ranges from 400-500 and the nozzle still is not even close to temp.

The picture shows the comparison between an Al and a 1018 steel pineapple. You can see after ten minutes the Al pineapple has heated up much better. The issue with this design is the fact that the nozzle still is not heated up enough. Even after 30 min (in video), the nozzle and valve are still not to temp. The next test will be with the new pineapple design and see if the nozzle heat up better.

The above video is the current setup, without the nozzle. This video shows that by removing the valve, the nozzle gets to temp in about 10 min. This is a lot more reasonable than the 30+ min it took before. The thought behind removing the nozzle is that when there is no piston pushing the plastic, there might not be any flow. Even a little oozing out would be tolerable.  The picture below is the same setup but with an AL pineapple. The pineapple distributes the heat better and quicker.

New pineapple and Heat Transfer data

Top Video: AL 6061 Pineapple and cap

Bottom video: Steel 1018 Pineapple and cap

I have designed a new Pineapple with a heater rod in it. Above the pineapple is the cap that will be press fit into the bottom of the pot. The 1/4″ NPT pipe is threaded into the cap and this video shows the temp over time. The heater rod is at a constant 500 F and is 2″ long. It was originally 2.5″ but this created hot spots on the tip of the pineapple because it was so thin there. This design should melt the plastic more uniformly and keep the pineapple at the desired temp. The thermocouple will be embedded in the pineapple to regulate its temp. The design is uploaded into the design section.

Business proposal

So I started getting some thoughts together on this and I need some help.

John- can you talk to your dad/grandfather about renting space and buying the plastic. If we wanna get that grant we will need to show that we have looked ahead and have a good understanding about our future investment. Eventually we want something in writing to add the the business proposal.

Sean- can you start looking into Kickstarter as a way of marketing and do a write up how we would use Kickstarter and other resources to get our name out.

Thanks guys

Grant Proposal

So I was looking last night at grant money and I ran into this one.

I applied for a grant between 1,000 to 10,000 and we have a month to write up a proposal and sent it to them.

Lets get our self some funding!

Basically we just need to send them a business plan and a bit more.  So we need to figure out some kind of business plan. I’m going to talk to my future father in law, he is good with this sort of thing.


Today we finished the electronic and mounted them on the device.  We tested them all and each part works separately. There were some interfearence issues with the temp sensor whenever any of the 12V electronics are running.  This is probably due to the arduino and the power supply not sharing the same ground. So goals for next time.

Finish making the spool and getting it to work on the device – flush out the final design for the spool.

Add adjustable mounting holes for the spool motor.

Add common ground to arduino and power supply.

look into repositioning the motor and the spool to shorten height

design housing for electronics

figure out more final design for electronics

Motor test