My Bot paid for itself in one project!

[twelchPTM]

A while back I posted some questions and eventually photos of a prototype minicell foam rockets. Well I just finished the final run of about 400 rockets.
I also sent the drawings to a foam manufacturer for an estimate.

400 is more then enough to meet our needs for a signifigant period of time and the foam guy told me in order to have them manufactured I would need to buy a trailer full of each shape and color (3 shapes in 3 sizes and 3 colors and a forth shape in its own color totaling 28 trailers) he said he might be able to work it down to one trailer of each shape (still 10 trailers). He also said he wouldn't even do the math on cost unless we were defianatly moving forward but the ballpark minimum was $50,000 to $100,000!!! (Plus we would have to rent space to store the massive inventory)

And I was worried that I wouldn't be able to justify the expence of buying the bot in the first place!

[Brady Watson]

Dude...pics or it didn't happen :D

-B

[twelchPTM]

sorry phone was on the charger....

[Ajcoholic]

where does the engine go??

AJC

[twelchPTM]

while i am pretty sure that was a joke, the launch stations used for these little guys is being finished up within the next week or two, I have a whole mess of gears and pulleys to cut out for the iner workings.
When its done I'll post pics and a vid!

[Brady Watson]

Pretty cool. For those who are clueless, Tom is 'the guy' when it comes to visualizing, designing and fabricating exhibits at Philly's Please Touch Museum. Gotta love it when a plan comes together :)

-B

[twelchPTM]

more so now that we have the 'Bot. It has gone beyond just exhibit building. I am making specialty fixtures and replacement parts for equipment all over the building. Also being that the building has been here sice 1876 - nothing is "standard" so instead of spending weeks looking for that off the shelf product that kinda maybe does what we need and then spending another week or two tring to mod it to fit perfect, I just make what we need!

[Ajcoholic]

while i am pretty sure that was a joke, the launch stations used for these little guys is being finished up within the next week or two, I have a whole mess of gears and pulleys to cut out for the iner workings.
When its done I'll post pics and a vid!

Well, I figured rockets need to fly... :) somehow (I knew there wasnt an engine.. at least not a fuel burning one).

Looking forward to seeing what makes these go!

AJC

[khalid]

Buying a Good and efficient Router from a reputable company with a good user forum and fast response support team always pays. I wish you best of luck for the remaining job and long live shopbot.
Those colorful pieces with good cut quality can not come from a DIY machine. I will be happy if you can share the Feed and spindle speed with DOC/pass with shopbot. How long those pieces completed.
My regards and thank you for sharing.

[twelchPTM]

the feeds actually varied from sheet to sheet, I ran my PC router at full speed with a base feed rate of 1 IPS. The thing about foam is that the amount of pigment added can effect the density of the material, which already has a variation of +/-.5lb. Simply put I ordered 4lb density material and each sheet had a marked difference in actual density with yellow being the softest (the more vivid the color the softer it will be). I tried a variety of style cutters but in this case nothing had a profound effect. In the end I used a standard .25" 2-flute plastic cutting endmill with a 1.25" LOC from harvey tools. I used a .25" DOC but suspect I could have gone more as the material offers up little to no resistance. A 4'x8' sheet took about 6-8 hours to cut (longer for the softer colors).
The trick to cutting this material is to spin the cutter as fast as you can and move through the material as slow as possible, the bigger your "chip" the more the material will tear in stead of cut.
I am starting another project with the same material but the finished product will be used in water so the slightly fuzzy texture of the rockets could cause issues, I will be conducting more experiments in the coming weeks with high and low helix cutters and seeing how slow I can actually cut before I start to melt the edges. If will share what I find!

[khalid]

Thomas, thank you for sharing the information. I have never used foam cutting on my cnc but the information provided shall be really helpful in case someday i started machining foam.

[supertigre]

What kind of foam are you using? EPS, EPP, HDU? Source?

[twelchPTM]

What kind of foam are you using? EPS, EPP, HDU? Source?

4lb cross-linked polyethylene AKA mini-cell (not to be confused with micro-cell