Allchin Gears- thinking of using pre-cut chinese

[Phil JOHNSParticipant @philjohns74870]

I am starting to build an Allchin TE 1.5 scale. I do not have the necessary gear cutters or indeed the machines to cut the gears so was looking for an alternatives before I mark out and drill the horn plates.

It would seem to me that chinese 1.5 module gears are almost the same diameter as the plans for the same number of teeth albeit a bit thicker but I could reduce their width.

What I was thinking was to buy a set or at least some of the require tooth counts and actually measure them when meshed on shafts and adjust the bearing spacing accordingly on the horn plates.

My two questions are,

Is this practical

and are there any other problems I have not foreseen with this idea such as clearance or interference with the parts?

[Phil JOHNSParticipant @philjohns74870]

[Bob Brown 1Participant @bobbrown1]

link

[JasonBModerator @jasonb]

Bit pricey those, have a look at these, I've used them on a couple of engines.

There is not much difference between the 1.5MOD and 16DP, probably best to plot it out and see where you need to move things, PCDs are easy enough to look up or calculate. As it's a 3 shaft engine

[John ReeseParticipant @johnreese12848]

Recently I bought 3 gears to replace the missing change gears on my Nardini lathe. I searched on eBay to find the best prices. The 40 and 100 tooth gears came from Chinese vendors. The 127 tooth gear came from the Netherlands. I was amazed at how inexpensive the gears were.

[John HinkleyParticipant @johnhinkley26699]

Phil,

My go to program for gears is GearDXF, available free from here:

GearDXF download

As Jason says, there's very little difference between 1.5MOD and 16DP. I just input figures for a 40 tooth gear and the difference in diametral pitch is 0.020 inches. If you have play around with the specifications of the gears you require, it will allow you to see the differences and make your selection of suitable gears easier to visualise.

John

[Ron LadenParticipant @ronladen17547]

Phil,

I have gone with a set of Chinese gears (picture below) for my electric engine, its my own design but a lot of it is loosely based on the Minnie. Scale is 1.625 and the gears I have gone with are 1.5 MOD.

The good points with the gears are price, the set cost 1/3rd the cost of the best UK prices I could find. They are well made and machined true and mesh together nicely.

The couple of not so good points are that they are quite thick at 15mm so the 6mm and 8mm width I need does mean quite a bit of machining. Also the dark ring you see around the teeth is from the hardening process which is on all of the gears and it really is hard, HSS doesnt like it at all so it does mean insert tooling then its not so bad. I have no idea if all Chinese gears are hardened this way so it was a bit of a surprise when they arrived.

For me the main reason for going Chinese was the cost, it was way cheaper than I could find anywhere else.

Ron

 

 

Edited By Ron Laden on 11/11/2019 20:50:51

[Phil JOHNSParticipant @philjohns74870]

Thank you for the replies.

The Geardfx download didn't like my iMac so it is going on my laptop, the laptop is slow but I keep a windows machine just for this purpose.

I will give it some more thought but as cost is a factor I'm leaning towards the chinese gears.

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