29 Replies Latest reply on Jul 9, 2018 10:28 PM by M. B.
      • Re: Help with Knurl and its design specs
        Frederick Law

        Diamond Knurl on round stock can be done with right and left hand coil cut in the model.

        You may want to model the diameter on the knurl bigger then stock because it is bigger after knurling.

         

        An easier approach is use appearance on the surface where the knurl will be.  Again you will need to model that area bigger so you can apply appearance on that area and not the whole shaft.

          • Re: Help with Knurl and its design specs
            Jaymin Patel

            I want actual feature which can be manufactured. Hope you can help with that.

              • Re: Help with Knurl and its design specs
                Kevin Chandler

                Jaymin Patel wrote:

                 

                I want actual feature which can be manufactured. Hope you can help with that.

                But this started as a hatch post: hatch Problem

                So, what's now driving the requirement for modelling the knurl, if I may ask?

                Is it simply an excercise?

                 

                From my experience, knurls are detailed by hatch and specified by text note with before (or after) knurl size dims and possibly locational dimensions, if needed.

                The machinist will know what to do with this data.

                 

                Cheers,

                 

                Kevin

                  • Re: Help with Knurl and its design specs
                    Jaymin Patel

                    We want to achieve this to communicate with our Customers as well as our Manufacturers. My boss wants me to work on it, and get the model right with said specification. we also want to utiliz the rendered part for marketing material.

                     

                    At any cost, he wants me to learn and make one.

                     

                    I interpreted the same as you said (From your experience........) and that was the reason I started as a hatch problem. When I reported to my boss, he told me to get this right.

                     

                    Hope someone can help me with this. I am a beginner and doing my internship.

                     

                    Many Thanks,

                     

                    Jaymin

                      • Re: Help with Knurl and its design specs
                        Deepak Gupta

                        You can specify the specs in the drawing like shown here: Dimensioning Knurled Features Drawings and for model/rendering use the appearance. You do not need to be accurate as this is for visualization only.

                        • Re: Help with Knurl and its design specs
                          Roland Schwarz

                          Your boss is ignorant and wasting time and resources. If you need a seasoned professional to tell him so send him my way.

                           

                          If you need something just for appearances there are other ways, e.g. decals.

                          • Re: Help with Knurl and its design specs
                            Kevin Chandler

                            Jaymin Patel wrote:

                             

                            We want to achieve this to communicate with our Customers as well as our Manufacturers. My boss wants me to work on it, and get the model right with said specification. we also want to utiliz the rendered part for marketing material.

                             

                            At any cost, he wants me to learn and make one.

                             

                            I interpreted the same as you said (From your experience........) and that was the reason I started as a hatch problem. When I reported to my boss, he told me to get this right.

                             

                            Hope someone can help me with this. I am a beginner and doing my internship.

                             

                            Many Thanks,

                             

                            Jaymin

                            Hello,

                             

                            Since you need it for presentation, how about applying a knurl decal?

                            You can make a knurl jpeg from a hatch on a blank drawing as the base for the decal.

                            I'm thinking this is a viable approach, but please other forumites, especilly those with more appearance/rendering expertise, weigh in on this.

                             

                            Also, I think Roland Schwarz's opinion of your supervisor is fairly accurate.

                            That your supervisor is pressing you to apply yourself and dig deeper is good, but he's doing so for what appears to be non-value added tasks (as you've read in many replies here).

                            This is bad, although there may be some valid reasons your boss has for driving this route.

                             

                            Regardless, persevere with this, but remember, you are only as valueable as the value you add.

                            Don't be the $100 answer to the $10 question.

                            This excercise doesn't sound like it's a lesson in value.

                             

                            Good luck and cheers,

                             

                            Kevin

                              • Re: Help with Knurl and its design specs
                                Dennis Bacon

                                I'm thinking his boss may very well be testing him and would love to hear him him state something along the lines of what Roland mentioned (maybe with different adjectives though). This brought back memories of me about 54 years ago when I worked in a giant print shop (summer job) and my first day there my boss asked me to gather up 15 (mystical) sky hooks.   I went all over the shop asking people who weren't in imminent danger of chopping their hands or fingers off (was somewhat common in those days). Each person would send me to another who was sure to know where I could find them.  I learned a great deal that day about the shop and how things operated. Who to contact for when I truly needed information on something. Within a couple of weeks I was one of the most valued employees.

                                Ah, heck,,, at my age I just like to reminisce.

                      • Re: Help with Knurl and its design specs
                        J. Mather

                        I have my students do one example with physical modeled knurl and another example with cosmetic texture.

                        Then the question is, "Do you really really need modeled feature?"  You have to make a decision based on your Design Intent.

                         

                        Knurl.png

                        • Re: Help with Knurl and its design specs
                          Dennis Bacon

                          I see that Mr. Salvador beat me to it. Solidworks Tutorial : Creating a Knurl Surface - YouTube.     Or that just might be a similar link.. Like every one else has mentioned, it is my opinion that you should use an appearance in your model and spec it in the drawing but it's kinda nice your boss would allow you to explore perfecting the model. Hope your boss has supplied you with a super computer. I did come up with something (from the tutorial) that allows for a good looking slicing up of the model but is not cut to any specific knurl callout. You would have to do the math. Took about half an hour for this to rebuild on my machine. Yea, resource hog for sure and it's still probably not fine enough but easily adjustable (if you have enough machine).

                          • Re: Help with Knurl and its design specs
                            M. B.

                            Jaymin:

                             

                            If your question is “How do I model a knurled part so that the model accurately replicates an actual real world manufactured part?”, then your question has not been answered.  It shouldn’t matter why you want to do this.

                             

                            Knurled part geometry is dictated by the knurling process not the designer.  Therefore, you must completely understand the process before you can model an accurate representation.

                             

                            This web page has everything you need.  https://www.accu-trak.com/technicalinfo.html  Be sure to understand how to calculate pre-knurl blank diameter and the resulting knurl outside diameter.  In Solidworks, the formula for Knurl Helix Pitch = Blank Dia. X PI / Tan (Centerline Helix Angle)

                             

                            Take a look at the attached part file and experiment with it.

                            The design table has red cells that you can easily change.  My company has several knurled part families that use this same modeling method.  Once our manufactured knurled parts are completed, they always match our CAD models. We only use Diametral Pitch knurls as they track perfectly on the 1st revolution which is the key to getting beautiful and sharp knurls.  If you want to use Circular Pitch knurls, the design table formulas I created will have to be modified.

                             

                            People have mentioned valid concerns about Solidworks performance when doing this.  We have knurls suppressed by design tables when we don’t need them.  When we do need them (3D printing, illustrations, and several other reasons), we accept and deal with the degraded performance.  I’d like to add that if Solidworks would fix bugs and make Geometry Patterns work reliably with parts that have multiple configurations, patterned helix features would be much more tolerable to use.