Help me Obi-Wan_Knobi, you’re my only hope!

[Dave ListerParticipant @davelister21379]

Hi,

I'm a Dave, boring but true. I work in engineering as an electrical designer, but have an interest in all things engineering.

I used to be a biker, built and restored a few, even won a few trophys!

However…

I am now looking for a supplier of small metal gears, google has sort of let me down, I don't want a 1000 from China, I don't want to buy a set from from the commercial suppliers because of the horrifying cost.

I am attempting to build something that requires a few minature gears, can't use plastic as it'll melt, so steel or brass (stainless would be perfect, but expensive)

So I call upon the power of Greyskull… oh wait wrong reference… the community of model engineers for some kind soul to offer his gear-cutting expertise and make a set of gears for my prototype.

I can supply a 3D pdf, a step model, an Autocad drawing, even G-code for a CNC of even a plain old pdf of the 7 gears I need, and perhaps another gear rather odd size/shape.

Anyone out there curious?

Now I'm here, off to browse the forums, some look very interesting and I suspect the wife will be tutting at me shortly.

Dave.

[Dave ListerParticipant @davelister21379]

Help!!

[JasonBModerator @jasonb]

If the 7 gears are a standard MOD size then you can buy individual ones from the far east at a price almost less than the bit of metal would cost let alone the cost of a cutter ontop of that.

Whats the size ( number of teeth & MOD) of he standard 7 gears.

[Keith LongParticipant @keithlong89920]

Hi Dave try following this link

https://www.technobotsonline.com/mechanical-and-fixings.html

towards the bottom you should see two headings "Steel model gears" and "Industrial grade gears", you might well find what you're after in there at much better prices than from the specialist gear suppliers.

I'm just a customer of theirs and have been very happy with what I've bought from them – small gears and motors!

Keith

[Dave ListerParticipant @davelister21379]

Mmm, thanks Keith for the link, not seen that despite hours of googling. Looks promising.

Jason, the specs of the gears I'd like…

3x MOD 0.5 48t Face-width 2mm (or less), bore 2mm for M2.5 thread.

2x MOD 0.5 10t Face-width 2mm, bore 2mm for M2.5 thread.

1x MOD 0.5 8t Face-width 2mm, bore 2mm for M2.5 thread.

1x MOD 0.8 19t Face width 2mm, bore 2mm for M2.5 thread.

1x MOD 0.8 148t Face width 2mm or less, bore 5mm, can supply a laser cut blank for this.

The last one is the odd bit, I have visions of cutting it by hand with a cheap dremel :/

Dave

[Howard LewisParticipant @howardlewis46836]

In UK look at HPC or Davall Gears, they may have suitable gears available from stock. And, no doubt there will be others as well.

Howard

[Anonymous]

Assuming you want involute form gears there's a problem with the 8 and 10 tooth gears unless you're prepared to accept undercutting, an increase in pressure angle or addendum modification.

Andrew

[Dave ListerParticipant @davelister21379]

The gear-train is not really transmitting any power, involute or cycloidal it's not a problem.

The 3D gears were drawn using the gears addon for Freecad. I also have a plastic set but would fail due to the environmental conditions I want to put the 'gadget' into.

HPC, believe it or not, my company supplies them with coolant filtration systems for the gear-cutting machinery, someone visited there yesterday. Small world.

I am now looking at gear-stock and pinion wire to part-off my gears.

Still, I would like someone to come on-board with a lathe to produce the gears and sundry items.

Dave

[KWILParticipant @kwil]

Anyone who proposes to use a thread to locate a working gear leaves me quite cold.

[Dave ListerParticipant @davelister21379]

Posted by KWIL on 20/09/2017 11:03:02:

Anyone who proposes to use a thread to locate a working gear leaves me quite cold.

HUH?

I have spent many hours searching for a supplier, I have got close, but the bore is wrong, or the face width, from my above post, the gears I require are distinctly non-standard.

I did try to design my gadget to use standard gears, but it would have been too heavy and large to fit into the space I have to work with.

Hence asking the modelling community to help me out. You obviously dismiss me as an idiot. Perhaps you could enlighten me as to where I could source custom made miniature gears for a reasonable price? I have a quote from Gibbs gears in front of me, I cannot afford over 500 quid for 7 gears.

Dave

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Dave Lister on 20/09/2017 12:28:32:

Posted by KWIL on 20/09/2017 11:03:02:

Anyone who proposes to use a thread to locate a working gear leaves me quite cold.

 

HUH?

< etc. >

.

Dave,

Presumably KWIL will correct me if I'm wrong, but:

I think his reference was to screw-thread, not forum-thread.

MichaelG.

.

[ Ref. Your post, yesterday, listing the gears required ]

Edited By Michael Gilligan on 20/09/2017 12:46:25

[Dave ListerParticipant @davelister21379]

LOL!!

My bad, apologies to KWIL.

Yes I suppose you are correct, but I need to be able to adjust the vertical alignment of the gears within the tiny space. The gear-train is basically a reduction gearbox, and the ability to have a 48t and a 10t locked together via a thread seemed like a good idea, I don't have the space for a grubscrew fastening.

oh well my search continues, although the link to technobots looks very promising.

Dave

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Dave Lister on 20/09/2017 12:43:57:

… The gear-train is basically a reduction gearbox, and the ability to have a 48t and a 10t locked together via a thread seemed like a good idea, I don't have the space for a grubscrew fastening.

.

If practical; it would, I think, be better to secure them to a common arbor using a suitable grade of 'anærobic retaining compound'.

MichaelG.

[speelwerkParticipant @speelwerk]

Madler **LINK** has the 10 tooth gear, all be it 4 mm width but anyone with a lathe can reduce that easily. The 8 tooth gear will be more difficult to get as Andrew allready wrote. Niko.

[JasonBModerator @jasonb]

Dave, you say you have the ability to part off pinion stock. So thinning down commercial gears should not be a problem for you and I would have thought that you should be able to solder or loctite in a threaded bush to bring the stock gears bore down to size. If so this really only leaves the 148T and 8T as being a hard ones to track down.

You also said that the commercial gears were expensive but I doubt you will find many people who would want to cut you say the 48T MOD0.5 gera for the £14 that HPC or beltingonline would charge.

[Dave ListerParticipant @davelister21379]

When I say "part off" I have a hand drill, an angle grinder with a selection of discs, a cheap dremel copy with some wheels, a junior hacksaw, and a small vice.

spd-si has gearstock, but an american outfit.

from the help I've been given here, I'll fiddle about with my cad model and try to accommodate standard gears, make more sense in the end.

Another problem is the damn forum, so many ideas so little time, i need a bigger shed

Dave

[speelwerkParticipant @speelwerk]

The 8 tooth is also available **LINK** Niko.

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