FreeCAD Gear Modeling and Design

In this life there are only two kinds of kids, those who have toys with broken gears and those who will have toys with broken gears. As we grow older, the toys become much more expensive. We start calling them by different names, appliances, tools, and recreational vehicles. Still, the problem remains the same. A gear is broke, the manufacturer no longer supports the product, and you really don’t want to part with more Centi-bucks for a new unit.

To combat this, I recently published a three part YouTube video explaining, step by step, how to create your own replacement gears. Part one first defines the problem. Then it’s explained how to make the necessary measurements. Finally, the viewer is exposed to FreeCAD.

In part two, the viewer is introduced to the gear workbench. This workbench makes gear modeling much simpler. Further expanding from part one, the concept of making stronger plastic gear teeth is touched on by controlling the pressure angle geometry of the gear tooth. At the completion of modeling, the viewer is presented with a finished 3d model of the compound gear. Lastly, the person is given a choice, either switch to the path workbench, to generate the g-code to run a CNC mill, or switch to the mesh workbench and generate an STL file to 3d print a replacement gear.

In part three, we start with the finished 3d model, a slicer program is demonstrated, and the necessary g-code is generated, all 180,000 plus lines of it. A time laps video of the gear being printed is shown, and as promised in part one, instructions are given as to how to install FreeCAD on your computer.

At the risk of stating the obvious, I am an avid FreeCAD user. I also have a fully CNC converted Shoptask brand lathe/mill. This tool is driven by custom motor drivers designed from scratch by me. The motors were $300.00 U.S. units I picked up surplus for $19 and change. Hence the custom drivers. Finally, drum roll please, it is fully controlled by Linuxcnc.

To be honest, for us on this site, this information, although new, is quite mainstream. However, for the average do it yourself enthusiast this is some pretty heavy stuff. My goal is to break out of the usual YouTube search terms and introduce Linuxcnc as well as FreeCAD to a much broader group of YouTube viewers. To that end I picked a paper shredder with a broken gear as the item to fix. The base title of the series is:

“Paper Shredder Repair 2019”

I have to confess this is my first YouTube video, but I’m coming up to speed rapidly as to how YouTube ranks videos. I would prefer you use the search terms, “paper shredder repair”, this should help present this series to a much broader group of viewers. If my subject rankings that day are high, the video could be at the top of the page. Likely, in the beginning, it’ll be much further down. However, you can’t miss it. While other content providers display their subject icons as a shredder in different states of repair, my icon shows my shredder lying on its side with a tomb stone on top of it. Kind of catchy huh? Well maybe, we’ll see. We’ll just call it my little experiment in visual marketing.

As you’ll see by watching my videos, I took great care to greatly simplify things so as not to scare off the entry level viewer. Still, this is not gear making 101. If the viewer stays with the tutorial, valuable information will be picked up regarding the fabrication of gears.

At the end of the day it all depends on YOU my fellow forum members. Please watch the videos. This will push up my rankings which will likely expose our interest to a wider group of potential followers. Even if their’s smoke coming from the kitchen and your kids a smearing sugar frosted goo on the living room upholstery, WATCH THE VIDEO! By the way, that kitchen smoke isn’t very heavy – – rite? Maybe you should let the video roll and do a quick kitchen check.

Above all, leave comments about the videos here. I’ll no doubt have to grow a much thicker skin, but I’ll read them all anyway. Have fun and I hope you’ll gain some knowledge along the way.

vbery easy as there is a simple way with the botton on pyert design and part
also drtaft got the gear macro

Hi pl7i92:

Just as a point of curiosity, do the last 4 characters of your user name refer to a control board made by MESA? Just wondering. I checked out your YouTube channel. Very impressive! It’s clear you are also an avid FreeCAD promoter. Are you also a FreeCAD developer?

Since you are also a YouTube content creator, I have some questions for you. Have you noticed a significant delay between the views received and the view count displayed to the public? Since I started the topic on this forum there have been, for several days, as much as a 63% discrepancy in view numbers displayed to the public compared with the number of views reported on the back end of my content creator channel. As of this morning, the public view numbers for parts 1, 2, & 3, were 27, 13, & 13 respectively. While on the back end, the view numbers were 30, 20, & 15. Granted, the discrepancy gap has, for the moment, closed. Still, why does it take so long to update the public numbers?

To answer your question, yes I was aware of the other methods to model gears in FreeCAD. I picked the gear workbench because I felt it was the most user friendly of the methods available to entry level users. That’s just my opinion. I have to admit your command of the English language is far better then my command of German. My total German vocabulary consists approximately 16 words necessary to get through customs and baggage check at the Frankfort airport. LOL! Therefore my comprehension of your video was as bit challenging. I relied mostly on the graphics presented.

As promised in the other topic I began some years back, I feel I need to partially introduce myself. First I am a published author. I have published articles which have appeared in, “The Home Shop Machinist” as well as, “QST”, which is an amateur, (ham), radio / electronics magazine. Since this forum has a global reach I probably should explain that the former magazine is on book store magazine racks in the U.S. as well as Canada. The same is true for the latter as well, but at one time that publication also had reach into parts of Europe. I am currently composing an article for the, “Digital Machinist” magazine which is a sister publication of The Home Shop Machinist. This one could be a revolutionary bomb shell for LinuxCNC. Of course, that’s just my opinion, only the reading public will make that determination. In the 3d printing community, there are many websites featuring files ready for print. Since the tolerances of artistic and some mechanical assemblies are non critical, most printers will duplicate the same object. Imagine if the same were true for LinuxCNC? I stumbled on a few hidden features of LinuxCNC which will accomplish just that. A word of caution though, in the U.S. there is a several month delay between submission and the time a manuscript goes to press. I’ll keep you posted on that.

To finish up, if you are planning to view the videos on my infant YouTube channel remember that the views reported on your screen are usually much lower than the actual view count. For a first YouTube video, and, I’m proud to say, three subscribers. This channel is getting off to a reasonably good start.

In this hemisphere the season is spring, and on my side of the planet there is still plenty of daylight to finish some outside work. Therefore I had best be getting back to it.

As for the videos, enjoy.

hope you get to the place wher YT butters you to get a video a day beside they do not promote you

Hi Andy:

I would dare say thank you is an inadequate response for all the publicity you got for my channel via hackaday.com. I’d also like to make a shout out to Jenny List at Hack A Day for all the kind things she said about my videos and my channel. Last Sunday afternoon, when I logged into the back end of that channel, I noticed view traffic requests at unusually high levels pouring in. At the time I could tell it was from an external source, but I couldn’t determine from where. Hovering over the external field, the help explanation hinted that it could possibly be from subscribers, but that made no sense since subscriber queries should be internal to YouTube. It wasn’t until Monday night that features on the back end of my channel began to activate. First, was global traffic sources. Prior to this, that was blank. Not long after that I was able to click on the external sources, which were now activated, showing a new menu listing external servers requesting information. At the top of the list was hackaday.com. Since it’s now Monday, other servers were also getting on board redirecting traffic to my channel as well. The reason for the delay in expressing my gratitude, was to give a more detailed tally of all that had happened. As of this writing, view requests are still at a higher level than they were prior to this event. When things finally settled down, my channel received a blast of well over two-thousand view requests. Also, in the global source table, some interesting things turned up there as well. It was rather expected that the U.S. would be number one, but Germany at number two was surprising. Next were Canada, the U.K., Australia, and France. The list goes on from there including view requests from the middle east and Asia. All and all, it was a very interesting experience.

All this leads to the following question. Andy, did you simply fill out the tip forum on their site, or do you have direct communication with Jenny? If it’s the latter, and she desires direct contact with me, give her the email I am currently registered with on this forum. I know that regular columnists occasionally run short of subjects to write about. If she wants to supply me with a general list of things she is looking for, I might be able to craft a video to fill in one of those dry spells. Besides, I could always use another blast of view requests.