Freehobbing is a very useful way to make a wormgear with common and simple tools you may already have. Using our calculator you can design the gear ratio... bit.ly/4cRochk
wormgearing and make the wormgear with a tap!
The Maker said "There must be an easier way"
Yes, there is an easier way for low consequence fine pitch worm-gearing. In fact a surprisingly inexpensive and somewhat simple method exists to accomplish worm-gearing. The modern explosion of mass manufacturing has reduced the cost of machinery such that many garages and can contain a small machine shop inside. The tools are here, but the way through the forest is not so clear. Now the design and manufacturing are put together for your use. If you have our calculator, 1/4-20 bolt, small piece of bronze, and a minilathe or minimill, you are set.
Patreon Files and Article can be found here:
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Chapters
0:00 Intro
0:27 Calculator
1:04 Minimum Requirements
1:14 Materials
1:25 Gear Blank Manufacturing
2:50 Run-in
2:58 Quarter Bit Box
3:50 Wormgearing for Electronics Instruments
4:32 Tap Selection
4:59 Tap/Bolt(Worm)
5:23 Lathe Setup
5:40 Feeds and Speeds
5:55 Depth of Cut
6:55 Fixture on Lathe
7:15 Pullout
7:30 Model Validation
The American Gear Manufacturers Association (AGMA) has a standard for the Design and Practice of worm-gearing but states clearly
" is not intended for use by the engineering public at large".
Since we are not constrained like AGMA, there must be some level of knowledge that could be useful to the curious and beginning designer/maker. Certainly, there is significant knowledge in all of the AGMA standards. What we show below has not been formally written anywhere that we can find.
The Core Principle
Worm-gearing at its simplest uses a hob to create the wormgear, and a threaded form (nearly identical to the hob) is used as the worm. A lathe can make a threaded part, which can be used to make the worm and the hob. At this point, you are tantalizingly close to making worm-gearing.
Making the modern wormgear requires equipment that is specialized and expensive. At least this is what one would decide by looking at modern machine tool builders websites like Gleason, Bourne & Koch and others. My conclusion here is that you have not found this post or the odd KZread video on this topic and have quit. I am glad you are here.
Even if you have found some references, they do not look like a repeatable design process.
Technical Nerdiness
The set we are making is called a single enveloping crossed axis wormgearing. Good smooth running, low vibration set for rotary positioning. Conjugate Involute Gearing. It is made for rotational positioning - a very low torque application. This free NASA Guide has a very good description of gearing in general and is suggested material.
bit.ly/2MGhbZr
Precision Worm and Wormgears
When your prototype works and you need 100, 1000 or more and you want it stronger - give us a call-thats what we do
(661) 333-3389
References
evolventdesign...
1/4-20 Tap:
2521A641 McMaster Carr Part Number for a 1/4-20 Tap $6.80 at the time of writing
amzn.to/3OWJ0Jk Amazon about $5.25
amzn.to/45q6s9a by Vevor. Amazing MINI LATHE at less than $700.
ANSI AGMA 6022-D19 Standard for Design Manual for Cylindrical Wormgearing
ANSI AGMA 6034-C21 Practice for Enclosed Cylindrical Wormgear Speed Reducers and Gearmotors
NASA Gearing bit.ly/2MGhbZr
Tools and Materials for This Project
Bearings amzn.to/3OLfDcU
Bore: 0.25X OD 0.75 Face 9/32
Drill Rod amzn.to/44qogQc
Anchor Lube amzn.to/3PdMMPU
1/4" Drill Bit amzn.to/3EewkZx
1/4-20 Tap Bottom amzn.to/3OWJ0Jk
1/4 Ball Bearings amzn.to/3qHNonM
Super Lube amzn.to/44p6VXH
Thread Locker amzn.to/44p71yx
Mini Lathe amzn.to/45q6s9a
Kool Mist amzn.to/3QTh0sU
Sharpie Fine Point amzn.to/3QTh0sU
NEVER SEEZ Blue Moly Assy lube amzn.to/3zNSPT0
THANK YOU
Matt Connley - thanks for the support on Patreon
Thanks to all of the KZread SUBS and Patreon subscribers
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