Thread: Gear cutting

FC check the DVD I sent you on the laptop ATM will do a search tomorrow and see if I can find it.

My thoughts would be if your doing straight gears not beveled cut like you were doing flutes using and indexing plate to set the gear cuts. A fly cutter in horizontal mode

Here Andrew

So an indexing head and tailstock holding the bar. Horizontal spindle with a gear cutter

Would that be the best option for something so small?

Originally Posted by funkychicken

How would I make a gear 8mm dia x 6mm deep? Making a heap at once from one rod is ideal

What does that statement mean,what is 6mm Deep.
Trying to decifer what you have asked is to me a challenge without more information.
Are these Gears going to have a Bore or will they just be Solid Blanks.
Will the gears be custom or are they to work with existing parts.
Do you have the use of a mill.
How many teeth are on the Gear.
Do you intend to make these from ground bar,bright bar or are you going to machine the material down .

Originally Posted by funkychicken

So an indexing head and tailstock holding the bar. Horizontal spindle with a gear cutter

Would that be the best option for something so small?

There are a number of ways you could do it depending on what machinery you have available .

Horizontal mill and a dividing head or indexer is the simplest and quickest .
You will also need the correct profiled cutter .
8mm is a pretty small gear and I think you mean 6mm wide not deep.
Getting down to clock work size.
Could be done in a lathe with an indexing set up on the lathe spindle and a single point tool sharpened to the correct profile held in the tool post and broached by winding the saddle forward and backward and feeding the tool in a few thou at a time until the correct depth is achieved.

Vertical mill ,again you will need a dividing head or some sort of indexer to get the correct number of teeth .Instead of cutting from the top of the shaft you would cut at the 3 or 9 o'clock position .
The cutter would need to be on a longer arbour to reach the center of the bar.


The all important piece here is the indexer , because that will divide the diameter of the gear into the correct number of teeth.
There are charts that will tell you what module and what series gear cutter you will need for the number of teeth and pressure angle .I am assuming you are talking about a straight cut spur gear .Helical cut gears are a whole different ball game and not some thing you could do unless you had specialist tooling and gear train set up for a milling machine and dividing head.

I tried uploading a PDF on gear cutting (workshop practice series book.) but it wont load up ,must be too big.
I can e-mail it if you want .

Kev.

Here is the set-up dscribed by Woodlee for a vertical mill. In this case a vertically mounted rotary table fitted with a dividing plate is the indexing device, and a fly cutter ground to the correct profile is being used to cut the gear teeth.

Frank

They'll be brass and will be used in a centre marking tool. They will turn through 45 degrees only and won't be under any pressure

Thanks for the help

Originally Posted by funkychicken

They'll be brass and will be used in a centre marking tool. They will turn through 45 degrees only and won't be under any pressure

Thanks for the help

FC ,
found this pdf ,I reckon this would be the easiest way to do it ,

http://www.neme-s.org/Model_Engineer...-PlaneGear.pdf

Kev

Ta