Make A Worm Gear

rdean said:
I used my rotary table to cut 72 slots about 0.025 deep to mark the teeth.
Click to expand...
The thing that is great, is that you demonstrate that it doesn't take much to do the trick. :encourage: The video shows the gashing cuts the teeth almost completely (and using an involute cutter). Whereas you cut only .o25 deep.

What did you use to cut the slots?
 
I used a long 1/8" ball end mill to cut all the way across the blank so I could cut 3 gears. The slots were not all evenly spaced as the end mill liked to veer off on some.

GEDC2025.JPG

I think the slots would only have to be about 1/4" long in the center of the cut just to start the teeth.

Cheers
Ray
 
When making spur gears, you can line up the blanks and cut several at once, but I would think worm gears have to be cut one at a time.
 
rdean said:
I used a long 1/8" ball end mill to cut all the way across the blank so I could cut 3 gears. The slots were not all evenly spaced as the end mill liked to veer off on some.
Click to expand...
Ray,
Did you angle the table to account for the pitch of the worm or just cut straight across?
mark_f said:
When making spur gears, you can line up the blanks and cut several at once, but I would think worm gears have to be cut one at a time.
Click to expand...
Mark,
You could cut a whole bunch much like threading a lead shaft and cut it into sections.
BTW, I hope you are feeling better soon!

Bob
 
RJSakowski said:
Ray,
Did you angle the table to account for the pitch of the worm or just cut straight across?

Mark,
You could cut a whole bunch much like threading a lead shaft and cut it into sections.
BTW, I hope you are feeling better soon!

Bob
Click to expand...

Thank you, I am doing better.
I having a hard time wrapping my head around that idea because I thought there's a concave groove in each gear.
 
From the video that I posted they didcut a concave groove but they also cut much deeper than Ray, ending up with a nearly finished tooth. It looks like Ray is just providing a shallow track to get the process started.
 
Me too "Get well soon Mark"

I just cut straight across the face to make 72 slots for the teeth of the hob to catch on. They weren't evenly spaced either because of the long, small end mill wanted to move around some but I didn't notice it until they were all cut.
After cutting the worms I came back and cut out the slots that were left between and on the outsides to make it easier see each worm cut.

Ray
 
I did learn a couple of useful things making these.

I cut these threads very deep probably past the center of the hob and the tooth count did not change. The teeth got thinner until they were destroyed. Not sure what would have happened if I had went further.

GEDC2010.JPG

I did find many different formulas for finding the diameter of the wheel and some were very involved and most confusing.

Here is the one I like the best.

How many teeth do you want? 72
Now add 2 --- 72+2=74
How many teeth per inch on the hob? 6
Divide teeth +2 (74) by hob teeth per inch (6) = 12.33333 (this is the circumference)
Divide the circumference by 3.14 = 3.928 (this is the diameter to start with)

The only thing you have to remember is to add 2. What could be easier?

Have a nice day
Ray
 
Now to make something useful from the gear.
I noticed the last time I mounted the vise on the manual mill that my back let me know that I shouldn't do that anymore.
I took the gear that I had made with three sets of teeth and cut two of the sets down to make a flat area. I then mounted them on a piece of 1/4" plate like this.

GEDC2034.JPG
And that was attached to this.

GEDC2054.JPG

Which made this.

GEDC2051.JPG
GEDC2049.JPG

GEDC2048.JPG

Have a nice day
Ray
 
Looking good Ray! :encourage:

Next, you'll get tired of turning the crank and find a motor... ;)
 
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