You can cut a rack in a vertical mill, moving the cutter and holding the blank vertically – just not a very long one! TBH I have no idea how they make long racks.

Right angle attachments are available for some machines. Then very easy to cut a rack to full length of the table long travel.

Here is one one on epay for a bridgeport

**LINK**

Hello Larry,

Norman and NDIY are both right, racks are best cut with a right angle head on a horizontal mill so that you can get the cutter down close to the table. I'm sure there will be a U tube video showing it being done.

The tricky bit then is to index the work correctly so that the teeth on the rack are all correctly spaced.

Ideally the driving slot is cut with a broach pushed through from one side to the other, but you can do the job on a lathe with a tool held in a bar and used that to shave off a bit at a time with the tool held horizontally and moved outwards by the cross slide between cuts. Hemingway sell kits that allow you to push such tooling through like a rack operated tailstock which saves a great deal of cranking of the carriage up and down the bed. You do save a bit of work too by opening up a suitable size of hole through the blank; it is best if you have drilled that before making the bore hole.

Did the gears you made also mesh together nicely? If so well done for a first attempt

Regards

Brian

There is a quick and easy way to do keyways in shorter lengths , just clock the centre of the hole on a mill and plunge an accurate sized cutter to the size of keyway you want down in steps until wide enough for enough key engagement , much quicker and less fiddly than doing it in a lathe , yes the top of the keyway is round but in most instances this doesn't matter, you make the height of the key to just fit in to stop lifting , heres a pic of a pulley with a 3/16 keyway only took 10 mins to set up and do.

Edited By Kettrinboy on 01/11/2018 09:03:16

That's a brilliant way to put in a keyway, you learn something new every day. Thanks for that Kettrinboy.

Doug

Hi Ian, The first photo shows the drive to the spindle ,as you can see the head is swung around by 180 deg and the drive gear is mounted to the main spindle.A reduction gear arrangement is clamped around the quill ,this originally was going to form part of the mechanism for a mechanical gear hobbing unit on the mill but was abandoned in favor of an electronic hobbing unit made by Richard Bartlett (Compucut).The keyed driveshaft transmits to the spindle via the bevel gears .The hardened spindle runs in bronze bushes in the spindle housing,the cutter is home made as in the book Gears an gear cutting by Ivan Law and at 1 1/2 inch diameter protrudes just enough below the edge of the spindle block to clear.The spindle block as can be seen in the earlier photo is held on the rear of the head column ,a diagonal brace connects to the main column and provides considerable support  to  the mounting.

The second photo shows a close up view of a shorter 20 DP rack.The vice provides the main support ,the two blocks either side are secured to the table with T nuts and milled level in situ to provide the support either side of the vice jaws.

Edited By John Pace on 01/11/2018 10:55:47

Thank you John (Pace) – very ingenious!

Regards,

IanT