Gear cutting

[Paul VassalloParticipant @paulvassallo49657]

Hi

I would like to gut some gears but I do not have any gear cutters, is there some one how could lead me to gear cutting

 

Thank you for all those how would be interested in helping me

 

Paul

[Paul VassalloParticipant @paulvassallo49657]

[John Stevenson 1Participant @johnstevenson1]

Paul,

 

Best thing is to buy the Workshop Practice book, Gears and Gear cutting by Ivan Law.

 

Covers everything for the beginner and more advanced user as well.

 

Very good book

 

John S.

[Ian S CParticipant @iansc]

Not very scientific, but the two gears that ihave cut (not critical for accuracy) were cut with a single point tool similar to a boring bar, the tool was ground using a suitable gear as a template, one has been running on a water pump for 10 years, the other has’nt been used yet. The calculations where mainly a guess work.  Ian S C

[_Paul_Participant @_paul_]

I am repairing a “Sparey” ML7 gearbox and trying to make my own gears I found the following sites very useful:

 

 Make lathe gears easily

Making gear cutters

GearDXF

Making Worm Wheels on the Lathe

None of these is my work & full credit to their authors.

I would like to second John Stevenson’s reccomendation Ivan Law’s book is very good.

Regards

Paul Floyd

Edited By _Paul_ on 18/12/2010 10:05:40

[Ian S CParticipant @iansc]

The book I ended up getting, after I blundered through making my gears was “Gear Wheels and Gear Cutting”  by Alfred W. Marshall  M.I. Mech. E, a MAP publication, not sure when it was first published, but the second edition was in 1947, and the forth edition, the one I’v got was published in 1977.  Ian S C

[Peter G. ShawParticipant @peterg-shaw75338]

Hi,

 

I would just like to advise that there some amendments to the first issue of Ivan Law’s book. See ME 06.05.88 page 528, 01.07.88 page 17, and 15.06.90 page 744.

 

Looking through my book, I also have pencilled references to: ME 3903 16.08.91 page 192 and ME 3905 20.09.91 page 337, plus the “W” dimension for both 20° and 30° pressure angles changed to 4mm. All of these pencilled references are in Chapter 12 Making Gear Cutters.

 

Of course, my book is the first issue: it is quite possible that a later edition may have these changes incorporated.

 

Regards

 

Peter G. Shaw

 

[Sub MandrelParticipant @submandrel]

I can commend Ivan Law’s “Gears and Gear Cutting”, but yes there are a handful of errors (mostly only affecting advanced stuff like bevel gears of differing diameters).

 

Perhaps we should try and have a ‘sticky’ thread with the amendments listed in it, as I don’t have all the ones Peter mentions.

 

Neil

[John OlsenParticipant @johnolsen79199]

It will all depend very much on what you want the gears for. For many model making purposes you could get by quite well with flycutters ground by eye to match a similar gear. The resulting gears will nto be perfect, but remember the ones on full size traction engines were generally just cast, as were many other large gears for slow speed operation.

 

if your application is a bit more demanding you might need better cutters…you can buy sets of cutters, they are not cheap but become worthwhile if you plan to do a reasonable amount in one size. I have two sets, one for 20 DP to match the Myford changewheels, and one for 0.5 module for small stuff. This sort of gear will be more accurate, but since you probably won’t be able to harden them without risk of distortion, won’t do for really heavy loadings and high speed. You can also hob gears, potentially giving better accuracy.

 

So if you wanted to make gears for application like motor vehicle gearboxes, you start to get into the need for really close control of the tolerances, and things like final grinding to size after heat treating become necessary. This gets a bit outside the amateur field.

 

regards

John

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