Screw gear, and worm gear, involute and parametric (Fusion 360)

[@drewartturbine]

Wow!! That’s amazing, I use parameters quite often, but I’ve never used them to drive such a complex design! Thanks for sharing, I’ve subscribed

[@andyj2106]

This is a great design, well explained. How did you arrive at the formula for the Twist Angle for the sweep? Building my own helical gear, I can't just use the helix angle, beta, as the Twist Angle as it is clearly (visually) incorrect: the value out of the formula looks better but obviously I'd like it to be actually correct rather than just visually correct.

[@nathanwilliams415]

Do you ever upload the Fusion 360 files so we don't have to model by hand and can just edit parameters?

[@yuriy77]

Hi, amazing tutorial, I watched a few times to understand your usage of parameters when designing. I have a question: I was looking for way to design a helicoid focusing gear set, that are used in lenses. Usually it's 2 sets of helical gears and they work together for moving the optics for focusing. What I haven't seen online so far is how to make an internal/external helical gear set that can be parametric just like you have here in this video. Any idea of it's possible/easy to parametrize that? I'm a relatively new into gear design so don't know the extents of the possible things you can do parametrically. Thanks

[@steelstone]

External gears follow the same rules as internal gears. They can be parameterized the sale way. I didn't play yet with internal gears. I guess they are the negative of external gears. So with Fusion 360, if you already have an external gear, with 3 more steps you can obtain an internal gear (circle on sketch, extrusion, and substract combine). Maybe add clearance on tip circle, remove it from root circle (tip and root are somehow inverted), and set some negative backlash on the tooth profile.

[@yuriy77]

@@steelstone just to show example of what I'm talking about is shown in beginning of this video: kzbin.info/www/bejne/o2SlYYeEoaZ5r80 There's the inner and outer helicoid, and I'm trying to model that parametrically so they mesh together and I could change parameters as needed (number of teeth, diameter, helix angle, etc..) I can model the pair somewhat using a plugin for helicoils, but I can't change the parameters once the component is made and have to go create new component from scratch again for a change.

[@steelstone]

@@yuriy77 OK, I see. I wouldn't call this "gear", it's more like a (helical or screw) rail. I think this should be easier to model than a gear as you don't need an involute tooth profile. You can start from one of my helical gears simplifying the tooth profile. I don't see any obstacle to get a parametric design as you wish.

[@yuriy77]

@@steelstone I wish I knew all the equation relationships 😂 to make it parametric. Digesting your parameter list. There's a lot there lol

[@imakemusic8851]

hi, can you advise me on how to change the lead angle of the worm (the angle between the helix and a plane of rotation). i am doing an experiment on how the lead angle affects the efficiency of worm gears and I need to print these gears with different lead angles.

[@steelstone]

On my model there is the user parameter that I call "beta1" which is the angle between the axis of rotation and the helix. I assume you mean the plane of rotation as the plane perpendicular to the axis of rotation, so you want "90° - beta1".

[@lilmisssunshine88]

hi, when i create the sketch for the first part, 0.08 seconds, how do i ensure that the plane is parallel to the axis? because i kept getting it being horizontal and the end product is not desired.

[@steelstone]

There are 2 planes constructed : Construct Menu -> Plane at Angle : Z axis (blue, up), "beta1_w" angle. Construct Menu -> Plane at Angle : Z axis (blue, up), "beta1_w + 90 deg" angle. So, these 2 planes are vertical along Z axis. The first sketch is done on the first "beta1_w" plane constructed. (my Z axis is vertical, that's the default orientation in Fusion 360)

[@MihaiDesigns]

Amazing work! This is wonderful for someone who wants to play around with the number of teeth and other settings in a parametric way. Could you perhaps share this file as well? What would be the license model for it? I'd love to showcase it on my channel at some point (and credit you of course).

[@DennisMurphey]

I am blown away literally. I need to make a worm and gear (17 to 1) and i have Fusion 360 but i have no idea where to start. It looks exactly like what i need to do where is the earlier video?

[@steelstone]

This video should contain all steps to design a screw gear pair from scratch with Fusion 360 (maybe get the user parameter list first from the given sheet link and import them in an empty project with the "Parameter I/O" add-in). I understand it might not be easy. So, start importing the parameters, then play/pause the video (at 0.25 speed) and reproduce steps. Some of my previous videos (helical gear, see my channel) might be more accessible to get started.

[@DennisMurphey]

@@steelstone thank you, amazing work!

[@DennisMurphey]

Printed my first assembly but the tooth contact is a little short. I need to add some clearance. thank YOU Stone Steel

[@steelstone]

What module and sizes did you choose ? I'm curious to see your prints ;) Try setting some value to user parameters bl1 and bl2. Say 0.05 or 0.1mm. These control the backlash.

[@DennisMurphey]

@@steelstone I hate to admit, l was unable to load the table. So I went back to brute force. Using threads I made a worm. Using combine I made gear profile. Then edited it down to one tooth and set them up. I am struggling on multiple fronts. Axle shaft space, max OD constraints and the required function of these gears is to provide 4 trigger pulses every 17 rotations of the worm. Regardless of total pulses as long as it matches the power drive gears. It's crazy but it's what I need. My skills in Fusion are elementary and my math memory is ancient. But I need these parts to work for a break through function in my 1950s model train. After over 5 years I have completed several 3D Printed add-ons but I must have a synchronized trigger pulse to time the digital smoke and sound to the mechanical linkage of the wheels on the Steam Engine. I have the pulse smoke puff and chuff sounds. But I don't have an accurate drive for a synchronous trigger for 2 of the old engines chassis. I post on you tube my progress. I know what I need but to get there is escaping my tiny brain. You video inspired me to take another run at the perfect design. But alas, I am missing some basic instructions to get started. I thought my bmversion was different. Then I found parameters in the manufacturing tab. But unable find how to import your beautiful table. There it is Steel Stone, Frankentrain Laboratories is stalled. Your work is beautiful my skills are too thin today to utilize them.

[@azkamaula]

What did you paste into the box in minute 2:21?

[@steelstone]

Rp1 * sin(alpha1_t) + ulH1 and then for the next lines Rp1 * sin(alpha1_t) + ulH1 * 2 Rp1 * sin(alpha1_t) + ulH1 * 3 and so on until Rp1 * sin(alpha1_t) + ulH1 * 7 I realize now that values and expressions on editboxes are not always easy to see on the video, sorry about that.

[@steelstone]

You can also use ulL1 * 5 + ulH1 ulL1 * 5 + ulH1 * 2 ... etc