process development for the ducts has progressed to the point joined sections of the duct surface can be "thickened"! using the "matching" tool set to position prior to joining the two sections was a must. given two "thickened" joined surfaces (ie: solids), I "added" the two together to form a single lumpy/crevassed solid.

filleting the resulting interface was the next step and I'm getting nowhere..... see attached image what I'd like to do is analogous to wiping an RTV fillet onto the part with your finger! the resulting interface from "adding" leaves a notch (ie: stress riser) and in my view is unsuitable for printing or casting. any thoughts on what I'm doing wrong or how to better proceed would be greatly appreciated!! SharkCAD Pro (1369) file attached. duct geometry is only representative for process development.

thanks!!

Art
[email protected]

murray-

as best I can remember (ie: configurations come and go when things aren't working as expected), they're not "mirrored", but very close relatives! imperfections ??? where exactly AND how were they detected/found?? my number one problem with SharkCAD Pro is the useless "error messages" and complete lack of "clues" when there's a problem that needs fixing........... your fillet is exactly what I'm attempting to make happen!! thanks

Art
[email protected]

following-up on murray's observation of "imperfections", I started poking at the geometry and don't understand what's going on. four surfaces are in play; 2 "Guide Cover Surfaces" and 2 "Loft Surfaces". both "Guide Cover Surfaces" appear to both "Match (position)" & "Join" AND both "Loft Surfaces" appear to both "Match (position)" & "Join". unexpected behavior results from attempting to "Match" either the matched & joined guide cover surfaces to the matched & joined lofted surfaces OR the matched & joined lofted surfaces to matched & joined guide cover surfaces !! it's my expectation that attempting to match two surfaces shouldn't result in loosing either of the surfaces..........
>>> what's going on with "Matching" ??
>>> is it attempting to tell me something ??
>>> and if so, what ??
>>> and is this related to my inability to fillet the next level assembly (see previous post above) ??

collage and file attached below. thanks!

Art
[email protected]

I'd try to avoid frustration deriving profiles from the work you've already done and model it solid. How is it intended to be molded, Art? It suggests blow molding to me, but the mold pieces and actions don't look easy with the branches converging and the floor between them. You've said that it's representative, not definitive, but it looks like a V-twin intake filter duct to me. Doesn't strike me as a bike engine aesthetic, but maybe a compressor or industrial engine?

Edited by user Monday, May 7, 2018 6:20:11 PM(UTC)  | Reason: Not specified

murray-

thanks! just tried the posted file and blending now works for me...........?? go figure as I haven't done a thing to the file!

"How is it intended to be molded, Art? It suggests blow molding to me, but the mold pieces and actions don't look easy with the branches converging and the floor between them. You've said that it's representative, not definitive, but it looks like a V-twin intake filter duct to me. Doesn't strike me as a bike engine aesthetic, but maybe a compressor or industrial engine?"

a friend asked me to take a look at what might be possible for a Weber 55mm DCO (not the DCOE with chokes) crossram manifold for an extended deck SBC. seeing the manifold design as both an extension of the work I've been doing on cylinder heads AND an opportunity to use the surface creation/modification tools that now dominate discussion on the forum, I agreed to take a look. implicit in taking a look would be my aerospace top-down requirements driven approach focused on engineering/physics and not appearance. 300 ft/sec intake flow rates are effectively equivalent to 200 mph where everyone understands aerodynamics is important!! attached is an image of an early version of the only option considered with exactly the same duct/port for ALL eight cylinders; the combined geometry constraints from the Weber and the two cylinder heads is a nightmare (but doable) !!! the resulting aspect ratio for the duct/port was 5 2/3 : 1 (ie: 4.25/0.75), well beyond everything else I've specified to date. in the end he decided to go with different length ducts/ports to get shorter runners with a more typical aspect ratio......... lefts AND rights doubles the work AND requires all the little things have to be spot-on so as not to aggravate the difference in runner lengths. at the end of the day it won't be hard to do better than the 40mm Weber
manifold he has given the obvious difference in its runner lengths AND inability to handle the 55mm DCO's!!

carbon fiber reinforced "printed" plastic is the stated objected for reduced weight AND heat transfer. one of my unspoken assignments is to preserve both a thin wall aluminum casting option and at least one forming option.............................


Art
[email protected]

murray-

the oldies but goodies (ie: Webers) keep popping up......... it's my sense avoiding electronics and the need for a computer is motivating the "take no prisoners" Webers approach. 55mm is 2.165" which means done properly there's a full throat path to the cylinder; remember SBC intake valves start at 2.1"

as for the impact of runner length variation, it's the #1 intake problem with my FFord Kent engines!! the inner pair and the outer pair require different jetting AND creative intake manifold porting to get the EGT values approximately the same in the power band!! and at least in Kent's, minimal EGT variation is the key to optimal ignition timing

Art
[email protected]

does anyone have any experience/thoughts regarding elimination of ripples resulting from the use of the "Guide Loft Surface" tool?? after building station sections on the order of every 1/4" of runner length, the "Guide Loft Surface" tool is producing surfaces that are almost usable. see attached collage. given the small difference in inlet to outlet area AND short length, I decided to go with the linear area approach simplifying things immensely. still a good deal of spreadsheet work but nothing compared to implementing a exponential horn with a fixed width.........

clearly I'm willing to consider ALL the usual suspect:
more stations
more guide curves
more compute intensive option/tool; assume anything less than 12 hours is on the table!
exporting to another (at this point unknown) application and then importing the desired surface

short side radius ripples are a non-starter for both a near-net printing and investment casting implementation................ thanks

Art
[email protected]

file without lofted surface 391 KB
file with lofted surface 2.11 MB

Art
[email protected]

rockyroad_us-

thanks for your input. as time permits, a couple of screen shots would help me understand your observations.

as for the four guide curves, the spline curves were created with points from each of the station rectangles; ie: the reason for creating the local x-axis and local y-axis. additional guide curves could be created expediently using the ends of the corner arcs that make up the station IF there's potential merit!

Art
[email protected]

UGMENTALCASE-

thanks, looks outstanding!! two question: 1.) "how" ?? and 2.) is your approach to doing the surface in pieces likely to be compatible with converting the resulting collection of surfaces to a solid AND then blending two or more of the solids? I started down the lofting road because it has the potential to yield a single surface compatible with Shark's other tools without the error messages encountered in the past trying to use matching, joining, and blending...................

Art
[email protected]