3d printed intake for N/A NA miatas
#181
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You can get pinhole free with bi-axial sleeve you just have to get exactly the right diameter or even slightly too large, and be very gentle with it.
Also, there's some pre-preg for the same price as dry cloth on ebay right now, its just expired for aerospace use, but should still be fine.
Also, there's some pre-preg for the same price as dry cloth on ebay right now, its just expired for aerospace use, but should still be fine.
#182
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The pinholes from wet layup bladder molding have nothing to do with the sleeve dimensions, it's trapped air from using compression inside the part. Vacuum bagging has a stack of materials design to allow the air to escape along with excess resin.
I could probably build a vacuum chamber, insert the entire part with bladder inside and the run vacuum to both the bladder and the rest of the chamber, and then slowly transition the bladder from vacuum up to 50 psi and get rid of them entirely. It is much easier to just DEI foil the parts.
Also, since I am set on building an oven I want to try using silicone plugs inside the mold and allow thermal expansion of the silicone to provide all my pressure. I need to experiment but that will save me from having to rotocast bladders.
I am on vacation this week and I am spending about an hour a day sanding the final plug to a 1000 grit and doing an acetone vapor bath for final surface polish. I cobbled together a solar powered vapor bath system by using large pot, aluminum foil, some bricks, and a large thermal mass (miata sport brake rotor). It works pretty well.
I could probably build a vacuum chamber, insert the entire part with bladder inside and the run vacuum to both the bladder and the rest of the chamber, and then slowly transition the bladder from vacuum up to 50 psi and get rid of them entirely. It is much easier to just DEI foil the parts.
Also, since I am set on building an oven I want to try using silicone plugs inside the mold and allow thermal expansion of the silicone to provide all my pressure. I need to experiment but that will save me from having to rotocast bladders.
I am on vacation this week and I am spending about an hour a day sanding the final plug to a 1000 grit and doing an acetone vapor bath for final surface polish. I cobbled together a solar powered vapor bath system by using large pot, aluminum foil, some bricks, and a large thermal mass (miata sport brake rotor). It works pretty well.
#183
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Why do you need the chamber, just the bag and a decent pump might actually be able to form enough vac pressure to crush the 3d printed part you're using as the core and mold.
But I didnt realize when you said pinholes you were talking about actual leaks and not just holes where the weave pulled apart showing off the abs under it.
But I didnt realize when you said pinholes you were talking about actual leaks and not just holes where the weave pulled apart showing off the abs under it.
#184
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I'm not using 3d printed parts as cores for the final parts. The final parts are going to be just 1mm thick carbon fiber. Dropping from 3mm to 1mm wall thickness picks up a ton of clearance and simplifies finding filters and elbows for the part. It also creates a much closer match for the inner diameter between tubes and elbows.
#185
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Thanks for the reply Alec!
The local printer is recommending he fuse the two pieces together with acetone... rather then use ABS cement to glue them.
Do you see any potential issues with him doing that?
Any chance the ABS cement will be stronger?
Could it be necessary to clock the pieces before joining them to clear a Mishimoto radiator in an NA Miata?
Thanks!
The local printer is recommending he fuse the two pieces together with acetone... rather then use ABS cement to glue them.
Do you see any potential issues with him doing that?
Any chance the ABS cement will be stronger?
Could it be necessary to clock the pieces before joining them to clear a Mishimoto radiator in an NA Miata?
Thanks!
#188
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I'm not using 3d printed parts as cores for the final parts. The final parts are going to be just 1mm thick carbon fiber. Dropping from 3mm to 1mm wall thickness picks up a ton of clearance and simplifies finding filters and elbows for the part. It also creates a much closer match for the inner diameter between tubes and elbows.
Just accept it
#189
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Found a local printer... it looks like he's going to print the complete version as a top/bottom half and bond/fuse/acetone them together once he's done.
Sounds promising, for sure.
If it works well, I'll get a second one made!
(And hopefully get the northern California Miata folks interested in them too!)
#192
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Have you considered using a soluble support material and just washing out the mandrel? HIPS could be 3d printed, wrapped with biaxial carbon, then VA-RTM to get something close to pre-preg. Not sure about the cost of HIPS though. Alternately, one could build do a two-piece mold and build mandrels from aquacore.
#194
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Your duct still looks undersized to me. If possible, get some calipers on there and post the diameter in mm.
Also, are you going to put new engine management in there at any point? I am wondering if a dyno will show much gain using stock ECU and a MAF. If there is a way to log IATs off of the stock ecu you should see a big improvement there.
Also, are you going to put new engine management in there at any point? I am wondering if a dyno will show much gain using stock ECU and a MAF. If there is a way to log IATs off of the stock ecu you should see a big improvement there.
Last edited by asmasm; 10-30-2014 at 10:56 AM.
#198
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Alec, the diameter is 2.75 longitudinal and 2.65 latitudinal where the elbow connects.
The 2.75 side of the 2.5 to 2.75 elbow fits over it nicely... and the K&N fits where it should as well... so who knows.
A MS is getting installed on this soon. Going to dyno it with the MAF to see if it's worth installing on our second Miata or not.
If it is beneficial, I'll have the second intake printed up by your guy, to eliminate any potential shrinkage/scaling issues this one may have.
The 2.75 side of the 2.5 to 2.75 elbow fits over it nicely... and the K&N fits where it should as well... so who knows.
A MS is getting installed on this soon. Going to dyno it with the MAF to see if it's worth installing on our second Miata or not.
If it is beneficial, I'll have the second intake printed up by your guy, to eliminate any potential shrinkage/scaling issues this one may have.