Making Clothing Round 1

All the black socks are cut.

We cut all the white/cream/pearl clothing, but one sheet has burn marks. We tried peeling the protection sheet before laser cutting to save time on peeling, but we will have to keep in on and peel after. The burn marks are quite ugly. We could sand them off, but it might just be best to buy another sheet of the pearl acrylic sample. 

Size of pieces were increased to 150% of .25" x .25" and most interior lines are 1.5pt-3pt in weight.

Light Color Side includes (50+ of each cut today, except for pearl parts)

• 1 translucent black sock
• 1 pearl bra
• 1 cream bra
• 1 pearl women's undies
• 1 frosted men's undies
• 1 white boxer
• 1 cream men's undershirt

Dark Color Side includes (50+ cut of first three listed): 

• 1 solid black sock
• 1 dark blue translucent pants
• 1 blue translucent shorts
• 1 orange sweatshirt (color tentative)
• 1 hot pink (color tentative)
• 1 magenta tank (color tentative)
• 1 green polo (color tentative)

Report 3 Update 2

Bubble

1. Justification and discussion of the process optimization and possible mold redesign. Include what problems occurred if any and give reasoning behind the parameter adjustments or mold modifications that were made that improved the condition.

The thermoform component in our yoyo is the clear bubble. We had no major mold redesigns. In fact, we kept the dimensions fixed and redesigned the inner diameter of the inner ring to fit closer to the outside of the bubble. However during the first runs, we ran into issues with the plastic not being fully flush around the pegs due. This posed a problem in the long run because the not flush plastic would cause a weaker seal  between the housing and the flat of the bubble thermoformed part, increasing the likelihood of water seeping out. The problem was primarily because there were not enough air holes around the die-cut pegs to allow the hot plastic to nicely conform around the pegs. We started with stainless steel pegs and then tried coiled pegs in hopes of making use of the interface for air to pass through and suck the plastic. The coiled pegs did not provide enough of a gap and we resorted to filing a flat in brass pegs and filing into in the peg holes in the mold. These corrections significantly improved the thermoformed part. We also changed the thermoform parameters to make the plastic conform to the pegs further. Below is table of our tested parameters for various runs.

	Run 1	Run 2	Run 3	Run 4
#02 Heat Time	150	225	225	225
#03 Form Time	100	100	200	175
#05 1st Platen Open Delay	150	150	200	200
#06 Cooling Fan Delay	25	25	25	25
#07 Cooling Fan Time	100	100	100	150
#08 Air Eject/Platen Hold Time	5	5	5	5
#12 Main Vacuum Delay	3/0	3/0	3/0	3/0
#13 Main Vacuum Time	100/0	100/0	100/0	100/0
Top Oven Temp	650	675	650	650
Bottom Oven Temp	650	675	650	650

Figure 1

Figure 1 shows the results from the 4 runs. At first, we increased the heat time and oven temperature so that the plastic would be more amorphous and conform to the pegs. Run 2, however, was too hot and did not hold its shape during demolding. To correct for this, we brought the temperature back to 650 and maintained the heat time while adding longer form time to allow the part to cool longer. We also increased the open delay a bit. Run 3 was pretty successful but we wanted to corrected one more time to get the plastic to conform to the pegs even better. The plastic was still pretty hot so we increased the fan cooling time. We decreased the form time slightly to activate air eject, which would break the vacuum and assist the formed part off the mold. Run 4 was successful. Each run is about 40 seconds.

However, after 20 runs, we realized the thermoformed parts were decreasing in quality. Figure 2 shows the results after 20 runs. Some parts were coming out not holding shape due to the machine overheating and some parts were not fully conformed to the pegs. We supposed this issue has to do with the faulty air compressor. For this lab we made 30 successful parts using the 2.999 diameter circular die-cutter. 

Figure 2

2. A fully dimensioned drawing of the part. In the event of a redesign, a fully dimensioned revised

drawing showing the new design specification as well as a fully dimensioned revised drawing of the

mold including matching revision levels.

4. Update the posted Gantt chart. (Your team’s component(s) only).

Due to the faulty air compressor, we will need to wait and hear back from the 2.008 staff to complete another production run. Alternatively we can produce 20-25 parts in a batch and wait 10 minutes before starting another batch. The thermoformed bubble part will be completed and die cute by the end of next week.

5. Post your component’s set-up sheet showing all the optimized parameter settings that will be used to run production for the component.

#02 Heat Time: 225

#03 Form Time: 175

#05 1^st Platen Open Delay: 200

#06 Cooling Fan Delay: 25

#07 Cooling Fan Time: 150

#08 Air Eject/Platen Hold Time: 5

#12 Main Vacuum Delay: 3/0

#13 Main Vacuum Time: 100/0

Top Oven Temp: 650

Bottom Oven Temp: 650

Report 3 Updates

1. REDESIGN

Justification and discussion of the process optimization and possible mold redesign. Include what problems occurred if any and give reasoning behind the parameter adjustments or mold modifications that were made that improved the condition.

1. Housing

The team that redesigned the housing consists of Tyler, Andrea and Cheetiri.

The housing had to be redesigned because we ran into many issues when the team injection molded the part. Even when parameters were changed in the injection-molding machine, the housing still had issues. The problems the part had were:

•    Wedging on the backside, which should be very flat to be able to be attached to the other housing. This was fixed my decreasing the thickness of the part as much as possible. 

•    O-ring groove was too small after shrinkage. The groove diameter was increased to 2% more than the O-ring to account for shrinkage.

•    The diameter for the snap fit was too big. The diameter was decreased but accounted for shrinkage of 1.65%.

•    The lip on the outer rim of the housing was removed completely since it served no purpose.

•    There was some flashing happening at the snap fit location, so the thickness was decreased.

Again, just the thickness of the part created many issues having shrinkage of 2-3%. The agitator had no issues since it fits perfectly with the thermoform bubble.

The ejector pins level was changed from level 6 to level 4. Also, the thickness might have to be increased a little, but that can be easily lathe. Nothing else would change.

B. Inner Ring

C. Bubble

D. Outer Ring

-          inner ring dimensions

-          outer ring (snap fit)

-          housing (snap fit)

-          housing (thick part, shrinkage, burning, warping)

2. DIMENSIONED DRAWING

A fully dimensioned drawing of the part. In the event of a redesign, a fully dimensioned revised drawing showing the new design specification as well as a fully dimensioned revised drawing of the mold including matching revision levels.

3. MASTERCAM

In the event of a redesign. A new set of Mastercam geometry files and associated G-code programs for the altered mold. Include the matching updated revision level in both file names as a suffix in the file names. Please do not print the code. The updated G-code files, (xxx.txt for mill), (xxx.nc for lathe) must be available for uploading to the appropriate machine at your machining appointment. The updated Mastercam geometry files must be available for toolpath review at your appointment.

The lathe and mill work for the housing molds are done. We just need to test it with the injection-molding machine. The files are uploaded in the course locker and were used during machining of the molds.

Lathe:

HOUSING_AGITATOR_CAVITY_REV4.NC

HOUSING_AGITATOR_CORE_REV4.NC

Mill:

HOUSING_AGITATOR_CORE_EJECTORPINS_REV4.txt

HOUSING_AGITATOR_CAVITY_RUNNER_REV4.txt

4. GANTT CHART

Update the posted Gantt chart. (Your team’s component(s) only).

https://docs.google.com/spreadsheet/ccc?key=0AhEy-axAED8UdHpickJiS1l6cV9RNGd2aWFfRTNCNkE#gid=0vv

5. OPTIMIZATION PARAMETERS

Post your component’s set-up sheet showing all the optimized parameter settings that will be used to run production for the component. Include the ejector-pin length, and shim thickness used for the mold. Make sure you have a copy of the optimized parameters when you submit a copy to us. You will need these to know these parameters when you are in the shop.

A. TOP RING (snap fit) w/ numbers

Injection hold pressure profile:

300	350	400	450	500
450	400	350	300	249

Injection hold time = 8.0 s

Cooling time = 25.0 s

Set screw feed stroke = 1.2 in.

Ejector pin length: 5.647 in. (#8)

Total shim thickness: no shim

Total cycle time: 33 s

B. INNER RING

Injection hold pressure profile:

Injection hold time = ___ s

Cooling time = ___ s

Set screw feed stroke = ___ in.

Ejector pin length: ___ in. (#___)

Total shim thickness: ___

Total cycle time: ___ s

C. HOUSING

Due to late redesigning of the part and no space in the injection-molding machine, the new housing has not been tested. We plan to test it on Wednesday or Thursday. We have made an appointment already, but we do understand that this should have prepared better. Due to the new thickness of the part, we expect to use the normal parameters set on the machine with a higher injection speed. The cooling time will probably be set to 25 seconds to reduce shrinkage.

D. BUBBLE

Not sure what the parameters are here…

What are people doing today? 4/16

Andrea and Tyler working with Dave on re-lathing inner ring.

 Ola tests some injection molding parameters.

That housing mold is harder than we thought...Doug and Chee will fix it.  

I ran 4 trials to find the parameters to get the part to spec. The main issue was the plastic not fully conforming around the pegs.

Ola and I decide that the tiny bubbles in the thermoformed part arn't worth stressing over. These parameters will do. 

 "Look Tyler! Finally these are the right thermoform parameters!"

Chee worked wonders on 3D Mastercam for the agitator in the housing mold.

 Tom finalized all dimensions and drawings.

The 2.99" die cut did the trick. Completed 30 final parts today.

 

CLOTHING is drawn!

Finished drawing outlines of various clothing in Rhino....ready to be exported to DXF. Tentatively, the clothing will be about .25" x .25".

For organization of clothing, we're thinking white/cream color clothes on one side of the yoyo and colors on the other side of the yoyo. There will be a misplaced black sock in each side acting as the "pointer"

White/Cream Clothing

• bras
• women's undies
• men's boxers
• men's undershirts

Colored Clothing

• men's shorts
• women's shorts
• pants
• shirts
• tanks

STILL NEED TO DO:

ORDER different color acrylics and test if acrylic will even sink.

SET up matrix of each article of clothing

TEST size and detailing of clothing

COLOR MAP hairline outlines in CorelDraw for lasercutting

CLOTHING Inspiration!

Meeting Notes

Blog should have at least one update weekly (what we did that week, what went well, what our problems were). 

Report 3: (not due this Wednesday)

Make the molds: Do they work? Do we have to redesign it?

If yes: We redo report two.

Redo ghant chart? Nope.

Clothing:, underwear and socks.

Parts (progress/who):

Top Ring (Andrea/Tyler/Ola)

Inner Ring (done)

Bubble (done)

Housing/agitator (Chee/Doug)

Clothes (Andrea/Jody)

To Do (By Tuesday):

n  Redesign SW of yoyo and molds (make the top ring turnable [increase channel width to fit tools, minimum 0.08], increase the circumference of housing to be flush with the upper ring, redo the agitator to be thicker and shallower. Make sure to add fillets. Insert screw/nut hole)

o   Need to get the dimensions of the screw we’re using.

n  Mastercam:

o   Agitator/housing (Chee and Doug work on this)

o   Top ring (Andrea/Tyler do the lathe, Ola is doing the milling/engraving))

Tuesday:

n  Give the Daves our list to order (O-ring, material for clothing)

n  Go over mastercam, redo if needed.

Wednesday

n  Machine all the molds