Kuma wrote:
Get yourself some ceramic insulation like Kaowool, you could also use silencer packing and wrap the end, if you can feel any heat on the outside then that is just wasted energy,
be sure to have a thermocouple attached to the tube so you can control the temperature.
Curious, what are you using for a piston seal to keep the hot plastic from extruding back?
something you have probably already considered, on your mold, I would think you need to preheat so the plastic going in does not solidify as soon as it hits the fixture
Hey Kuma thanks for the feed back.
Let's take these one at a time because it seems like you know something about this and I do have some questions because this is not my trade.
1) Kaowool insulation to stop heat loss -- I didn't even think about that.
2) Thermocouple -- I'm actually having issues with this.
I welded a threaded coupling nut on the tube and then drill a bolt to except the thermocoupling so it don't fall out. The tip of the thermocoupling touches the tube.
It reads the run up temperature perfectly according to my heat gun but then when it shuts down the controller the thermocoupling is still reading high and it takes a very long time for the temp reading to drop. By then according to my heat gun the tube reads HALF the temp the thermocoupling does before it kicks the controller on again.
I don't know what causes this. I even tried to lay the thermocoupling on top of the tube on hold it there with a hose clamp but no cigar. Same readings.
I don't really know what to do about this because I don't know what I'm doing wrong and I'm NOT an electron mechanic. I hate electrical and I'm no good at it.
3) Piston seal -- Yes I've thought about this but the pipe I'm using is just a piece of water pipe with the seam inside. I know this was a bad choice. As a result I had to notch a groove in the front end of the rod for clearance. So my idea was to load up most of the tube and since I'm only going to use about the first 4 or 5 inches (first two heater bands) I figure the unmelted plastic bits at the back end with cause a back stop. This "might" be wishful creative thinking but if it fails then I will just buy a piece of seamless tube instead of using pipe.
4) Preheat mold -- I'm not sure but I don't think this is going to be an issue.
The molds I'm going to make are not going to be cnc made or even all metal. I've come up with another idea. It's just different and you'll see as this project goes along.
Failure is an option.Anything I make will most likely be small. I was thinking of making an original copy of the FL350 shifter knob as my first project.
Any feed back positive or negative is always welcome.
It gives me ideas and makes me think.
NOBODY has the lock on good ideas and anyone's yap is important.
I know I'm not the smartest guy on the planet but I try.
FAILURE IS AN OPTIONCO