3d Printed Intake Manifold Air Box

hey this is Keith I'm going to show you how I 3d printed an intake manifold so the airbox that I started with is designed to adapt these two and three-quarter inch inside diameter throttle bodies that my dad built to a standard carburetor flange style intake manifold that's a 4150 pattern on there it's made out of quarter-inch aluminum on the bottom and some eighth inch aluminum for the sides and top just make welded together that's one of my first aluminum MIG weld projects this is set up for a fuel injected manifold so we've got throttle position sensor idle air control motor here housing pulled off a different third gen Camaro and welded on there intake air temperature sensor a couple of ports for like your fuel pressure regulator and map sensor this manifold box worked pretty good no problems with it and they haven't ever blew up or anything the engine probably easily made thousand horsepower on it but a couple of challenges with it obviously the air flow has to make this 90-degree turn and the box is not set up to make that a streamlined path also these front holes the screws to screw this down to the manifold are obviously inside the box I've never had them come loose but the challenge was more getting them loose and the fact that you have to take everything apart to get to those screws that he wanted to take the box off to look at anything so designing this air box would be 3d printed the number one thing I wanted to take care of was smoothing out that airflow so I started with the circle that's the inside diameter at the throttle body and then half of that opening into the intake manifold down there and lofted a shape that gave me control over the short side radius here and and the way the flow changes shape from obviously from a circle to more of a D shape there so I started with this shape because that was going to be the easiest way to model the rest of the part then I thickened that part out so that we had some some material there to work with and and then mirrored it added bosses here and in holes to bulldoze throttle bodies - it added a throttle cable bracket bosses for sensors and things like that and one thing I did to address the bolt hole through the air passages was added this hole in the center in between the two of them and and I figured while I was doing that I might as well build a triangle pattern around there with the bolt locations as close to this perimeter as possible to make sure that they could hold the Box down securely and not break anything off so I got so all three of those holes are actually in different locations being the original carburetor flange holes so since I was going to be 3d printing this obviously had to pick a material that was resistant to gasoline to ethanol so I usually run a flex blend also something that could take the heat of being under the hood and also that could take you know had some strength at those elevated temperatures since again supercharged set up here and not with a high amount of boost but make sure that we don't blow the thing up so one of the materials I found that was compatible with a lot of those requirements was poly carbonate poly carbonate is a bit trickier to print on the 3d printer because instead of printing at 200 degrees Celsius like entry-level materials it prints at 300 or more also requires an enclosed building Borak wires a heated bed plate pretty hot environment to print it and have it come out well so you see my 3d printer behind me it's a pretty inexpensive printer it's a $200 FL Sun cubed printer with some modifications to it some of those modifications include upgraded extruders all-metal hotend a bed sensor to square things up a little bit better obviously an economy job here of enclosing the printer and with a blanket and kind of boxing it off to keep keep the heat inside the bed on this printer right from the factory I didn't have any trouble going to about a hundred and ten degrees C which is good for polycarbonate material and with the all-metal hotend I didn't have any trouble cranking that up to well over 300 as well without melting anything all right so the material I printed the first print width was a polycarbonate material this came off Amazon's kind of a knockoff material that's why it says Ollie carbonate I was about thirty five dollar spool of material which is a kilogram it's bad enough to make probably two of these boxes without any trouble the first print that I did with this talked about the print defects first here you can see you see a line right about here and another line down here these are areas where I had to fill in and jam on me and so then I had to go in slices a g-code up bring the printhead back down clean everything off restart the print work my way up so did that twice just printer tuning problems with the new filament but otherwise turned out really neat you can see when you rotate it here all those little curves that got turned into line segments kind of a really neat effect on the on the print strength-wise pretty strong print even with those relatively thin walls there so no problems there I printed this with the slicer building the support for it so that was a little bit of a challenge to remove I'm talking some of the later prints about how I got over that but not a bad first print now so when I went back to the CAD for the second version I wanted to try a couple of things I added a little bit of material to the throttle cable mount the first version seemed pretty strong but I just want to add a little there also when I had the box on the intake manifold it just looked a little bit small and most of that was because it didn't cover the top of the flange so I brought these this out a little bit and I moved the tabs back from my alternate locations to use the factory carb back hole locations that way I went up to drill to extra holes in the manifold and it would cover a little bit more like I said so I also wanted to take a shot at adding the idle air control motor back into the design so I built a boss for that with a port that I could thread up front to bypass the throttle bodies since this is supercharged and also since I didn't have in him 20 tap I drew in the threads and experimented a little bit to get the size right on those you so this is the second design print the print turned out with no defects material printed really nice temperatures stayed nice but design wise I had been testing this idle air control boss all just as a piece by itself and the way it was cooling and shrinking was a little bit different than when I printed it as a part of the whole box so it didn't shrink as much and so I'm you know the spreads don't fit also since I had this partner was actually getting I was getting close to something that was workable I took it and I set it in the oven cranked the oven temperature up to 250 degrees and I was expecting this material to be pretty firm because it's supposed to be polycarbonate but even at 250 degrees I could put my hand on here and wait a decent amount of pressure but I could squish it down and it was starting to get springy so the material that I was using I know it was a little bit more on the cheap and so I probably was getting a polycarbonate blend I had some other plastics in it that's good because it makes it easier to print and it's probably why I got you know such nice prints out of it but with a not being a hundred percent I couldn't guarantee that it would be chemically compatible and not melt or break down with alcohols and gasoline's but I also probably didn't have the strength or the temperature resistance obviously that I thought I was gonna have so for the third version this part I didn't make any changes in the CAD but I did find an alternative material since that poly carbonate wasn't gonna cut it at least the fake stuff I had and this is a nylon material fiberglass reinforced has 30% fiberglass in they're supposed to have really good heat deflection properties it's also very similar to what a lot of current plastic car intake manifolds are made out of there's a bit pricier it's $68 for three-quarters of a kilogram so it's right on the edge of the amount needed to make one of these boxes now the other challenge with it was it was a really tricky to print and especially with my printer I didn't have settings to go off of so I had to work a lot and figure out what was going on with this first print I was getting it to stick to the bed pretty good but I was getting a lot of a lot of junk hanging off of it there I was also printing this with a brass nozzle and with the fiberglass in the material it's really abrasive and so I'll show you what the nozzle looks like I was printing with on the left is a used but not used for this material 0.8 millimetre nozzle and on the right is the nozzle I was printing with the tip from being drug over the print with all this junk hanging up actually around the tip right off there and then the hole and large part of that is because inside as the nozzle got shorter is bigger but also did enlarge the hole itself a little bit too so I got some more settings dialed in with the material starting to look a lot better there's still a lot of this fluffy junk on there but this was an example where the sides were starting to look much nicer good solid fill had a little bit of trouble under extruding there and then I printed this one still settings are even better govern under extrusion problem mostly and then I tried actually print this upside down here this way I wanted to just double check that I could print thin overhangs but this was this is looking much better now if you can see that rocking a little bit there this was this was warping quite a bit so I was printing this on the aluminum bed with the Kapton tape on there and it was warping so much it was actually pulling the tape up off of the surface so I knew I knew I needed to solve that problem definitely by using like kind of more like this when using a full bottom layer to keep the part stuck on there and then you know getting a good wide brim around it too so I swapped out that brass nozzle for the steel nozzle I mentioned earlier in the printer topic and then I printed this full piece here printed out pretty good the biggest problem with this one it's actually one of my better ones as far as no defects almost all the way up here I'll talk about this one a little bit later when it got up to these tabs once we got above the height of this boss here it was it would print this little rectangle and then a little rectangle here over to the other side do the same thing and then work its way back and forth it spent so little time of course printing these and I didn't have a minimum layer time set that would have prevented it from continuing to go back and forth that it was just starting to melt them off and so I tried a couple of times to stop the print and trim these off and then restart to print down at that level but I couldn't get it to read here well enough and when I would put in a minimum layer time then the material would ooze out of the nozzle and without the right amount of prime it wouldn't there would be nothing left in the nozzle so it would try to print that tiny rectangle and nothing would come out of the nozzle so obviously that's a settings problem because a printer with all the right settings might be able to print those you might even need a layer cooling fan at that point but I didn't I didn't have that so I decided instead that I would make some design changes to the next design the other thing on this one I did an experiment with drilling and tapping or tapping these things and you know really just make sure this would fit well in drilling and tapping this pipe fitting here this is a quarter inch pipe and in winding the fitting in it's hard to see but on the very top I ended up splitting that housing so that's just one more thing I thought okay well in the next version I will just make that a little bit thicker and then of course try to be careful winding in anything that's tapered because it generates a lot of force you don't need that much to seal it and you don't want to split whatever is you are winding - all right so when I went back to the cat for version 4 of this part I quickly took these tabs in the back connected him with a straight across section so that that was a solid piece that way when it was printing it'd be printing a long area and there be more area for the heat to go into I wouldn't be melting all those little tabs the other thing I wanted to talk about quickly was to support structure so for these upside-down surfaces here normally you'd use the slicer to generate support but when I do that it generates support all the way down to this surface and makes a mess out of that surface and all the way down to the base plate so that's like five inches of support it has to build to get up to that surface same for this surfaces I don't know about for three and a half inches up to this surface and it's a pretty small surface you can almost get away with bridging it if you didn't care what it looked like underneath so what I did instead to try to make it as simple as possible was I just designed the support right in the cab I've built off of the model so that there would be no support and then it would just grow out of the side of the model when it was up high enough that it needed to start building like 45 degrees structures out I could build just what I needed to be able to bridge and I think I chose about 200 thousands for the distance between those spans so no trouble bridging it with the material they were easy to remove because I only needed a razor blade across these little sections here and took up the least amount of material other than that I don't think there were any major changes to this I thickened up this boss like we talked about and just in refining a little bit I was able to get all the affiliates in around here to try to make it look really nice so this was how the fourth part turned out I got my flange up here straight across no trouble printing it larger boss over here didn't crack when I thread it in the pipe thread pretty good print this one was actually good enough that i siliconed it onto the car I did the heatset inserts up front they're a little bit tricky to do because this print was kind of warped but I got them on there I got the parts sanded up well enough to bolt this on the car and use it so I idled the car up to temperature and wasn't having any trouble with it aside from the throttles were just a little bit misaligned so I was idling a little bit high I drove the car round in the driveway just a little bit and then I administer all the car and when I went to refire it I had an intake manifold backfire and it actually blew out the side of the part so I heard the big pop when I looked under the hood these pieces were nowhere to be found boxes just looked like this right so I guess I lucked out in the way it was a pretty pretty awesome test any literature I could find can't estimates intake manifold backfires can be you know around the order of 100 psi that's far more than any boost pressure numbers I would see with the car and so it just kind of gave me an indicator of hey what's it look like in here B how would this thing fail and and see what kind of pressure should I expect it to take if I had it on there built the same way this one was built so when I took it off I ended up splitting it apart the rest of the way to take a look at whether I thought each layer was fusing to the previous layer well enough that doesn't look great to me I think there could be some better layer adhesion there so I ended up moving the temperature up about 10 degrees on the next prints and I also took the opportunity to thicken the part up again I was starting to buy more materials so I wasn't worried about trying to finish it in one spool so I figured I would thicken the part up some the way this part is built it's always going to be weaker in this direction this is the layer adhesion direction the Z direction so that's just a challenge that is always going to have to be compensated for either by making the walls thicker so there's more surface area for that tension force to pull on or by reinforcing in some other way so I went back to the CAD one more time and the first thing I did was thicken this surface more than it was before so we had a thicker section the way around I also extended these bosses around the heat set inserts added some strength there I thickened the bottom flange too I got bumped that up maybe a sixteenth of an inch or so I added some ribs in this area too they were a little bit challenging to model but I thought they looked kind of cool and they would add a little bit of a little bit more surface area to the section all along here I didn't want to do it at first because I knew I was gonna have to be asymmetrical with the throttle body bracket over here but I think I came up with a good way to kind of make it look like they were similar without having this one extend all the way through I also closed in this bottom surface here this is kind of challenging to do in the cab before there was a tiny gap that extended all the way down into this recess here but I was able to close that up and then fill it all the way along here again I wasn't worried about material use anymore I'd already used more printing these things than I was going to use printing any one more so I just added it in anywhere I thought that it could be useful all right and this is the print result from that final set of design changes this print took 20 hours I believe a couple of defects in it there's a issue I ran into here I had the rapid speed set too high on the printer and that caused the head when it was making a longer distance move to run into some debris on the print and knock the X and the y-axis out of sync and then it printed about a quarter inch of material on top of this offset to the side like when you get a layer shift so I got lucky I was able to knock that material off of there take the print back down where it should be adjust the g-code and get pretty good layer adhesion I think obviously it creates a pretty bad looking line across the whole print but this wasn't quite perfect anyway for some reason there was some some pieces that didn't melt out or maybe this was where a layer ended or something repeatedly in that area so doesn't look quite as nice as some of the other ones the inside turned out nice warping was really limited top printed without any trouble I was able to drill and tap all the fittings in this without any trouble ribs turned out really nice on there the heat set inserts I did a much better job on these than before with the part shrinking a little bit and a little bit of warping happening no matter what you tried to do when I designed with these holes built into the part and a little bit undersized of course so that I could drill them out they were never quite square and I mean the best thing to do would probably be to put this in a milling machine and then you could precisely drill these holes in and even use the milling machine maybe to push the inserts in so they stayed nice and square in the previous designs when I did this I just tried to do it by eyeball I drilled him out and then just stuck the inserts in hoping they would square themselves up to the part of course they didn't and then when I went to both the throttle bodies on I had trouble with the holes lining up and it wouldn't clamped down right so this time instead I took the time to carefully sand this space and get it as as straight as I could and then I put the throttle bodies in place and found the best place that I thought that they should be and clamped them to the box and then with them clamped into the box I drilled using the same drill that I used to drill these I drilled into the plastic and then repeated that for all of and making sure I was really careful to keep the part clamped really nice now with that done I had holes that were right where I wanted him then of course the holes were too small for the heatset inserts so I carefully stepped those holes up one drill letter-size at a time till I had him up - I think it's letter O and then I heated the inserts up using the soldering iron like before and then I would push them in and then quickly flip the part down on the glass bed and hold it down and that way the heat set insert would because they tend to like push out would push out and be nice and square with the front face and hopefully would be concentric with the hole as well I'm so they went in there really nice the throttle bodies bowled up to this really nice and since I have this you know as as planar as possible the throttle bodies don't bind and they clamp up pretty well there but that took a little bit of trial and error a couple of times to learn how to put these in best well you don't have a milling machine handy the bottom surface just gave that a quick sand with the power sander and then a little bit by hand to square it up didn't have to be perfect anyway because I'll put a bead of silicone around that just will sit on on top of the manifold this area here got a little bit tight if I print this again I'll loosen this up so the mine cap screw drops through there a little bit easier but it does work as is all right and that's what it looks like with the throttle bodies bolted up use a little bit of black silicone in this connection here just to seal it up real good a little bit of teflon tape on the intake air temperature sensor and quarter-inch fittings I'd left the idle air control valve as is seal up just fine and a little bit of teflon tape on that - six fitting for the bypass some black silicone on that bottom up against the manifold and then they'll have a nice smooth ER path for that air in the engine

Channel: KBo540

Views: 2,382

Rating: 4.8961039 out of 5

Keywords:

Id: pC3xRtzD6-U

Length: 24min 18sec (1458 seconds)

Published: Thu Mar 19 2020