Helical Gears 1

[Azum]

Probably not good asking this just before Christmas but here goes
I am trying to make a model using helical gears on parallel shafts
The content centre models seem to be for shafts at 90 degrees
ie Mod 1 30 teeth parallel shafts pcd is 31.5
the same for crossed shafts pcd is 42.43
All content centre gears are for crossed shafts

Does anyone know how to get content centre gears to do parallel shaft gears or know a website where I can get both types

Many thanks for any advice

 

[SincoTC]

I don't know of any Content Central models that are parametric or any models with parallel axis helical gears, but I haven't looked seriously for a couple of years.

I needed a model for rendering and wound up doing them myself, it was fairly easy (I didn't go overboard regarding the detail of the tooth profile) but they looked pretty good. However, unless you need to render or to demonstrate to to a client with no imagination, I would'nt bother to model them fully, just do revolves of the major dimensions and show the correct PCD on a sketch for mating to another gear. The detailed model took 8.5 seconds to rebuild on a 64 bit system, but with simple revolves it only takes 0.01 seconds, so take your choice.

Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK

SW2007x64 SP3.0 Pentium P4 3.6Ghz, 4Gb Ram ATI FireGL V7100 Driver: 8.323.0.0
SW2009x32 SP1.0 Pentium P4 3.6Ghz, 2Gb Ram NVIDIA Quadro FX 500 Driver: 6.14.11.7751

 

[Azum]

Thanks Trevor
I am not looking for something containing fully accurate teeth profiles just something that shows the correct pcd and is recognisable as a helical tooth form as opposed to straight or someone will try and fit a straight tooth gear working from the assembly BOM and GA. I am sure you know the way it happens. If I have to I will model one myself but was just being lazy and looking for a library that might contain one. The PCD of the SW ones are 11mm out on a diameter of 30mm so I wanted a bit better accuracy than that if possible.
Many thanks
Clive

 

[SincoTC]

In that case, I'd just add a referance plane at the calculated Helix angle, create a sketch on this with an approximate tooth profile and do a straight extruded-cut and then circular pattern this cut. It will look like a helical gear, especially if you can get the profile sketch near mid width. Don't bother with swept helical cuts unless the tooth face is long or the tooth numbers are low, This would be the correct way, but it will kill performance even more than this way.

Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK

SW2007x64 SP3.0 Pentium P4 3.6Ghz, 4Gb Ram ATI FireGL V7100 Driver: 8.323.0.0
SW2009x32 SP1.0 Pentium P4 3.6Ghz, 2Gb Ram NVIDIA Quadro FX 500 Driver: 6.14.11.7751

 

[MadMango]

If gear train design is a common task in your line of work, you may want to consider purchasing the GearTrax add-on software form Camnetics. For the purchase price (~$800) it is highly functional and accurate. It is one of the few products that will actually save you money over the long haul if used just a few times a year. They even offer a 10-day free trial.

http://www.camnetics.com/geartrax/index.htm

 

[Spurs]

My experience with GearTrax is that for helical gears is it not geometrically accurate.

Try going to Web Gear Services Ltd website

http://www.webgearservices.com

and they offer both software that will make 3D helical gear models - accurate enough even for master gears - or they can create a model for you