anybody here willing to machine some gears?

[superspec]

guys i along with many other nissan people need some help. nissan took the cheap route when making the gears for our sunroof motors. they used plastic. it is very common for the gears to sheer a tooth or just break the gear. you cant just buy the gears alone you must buy the whole 300 dollar motor. when mine broke the last time i bought 2 motors and used the gears to make one good motor so that i could close my sunroof. i havent opened it again in the past 2 years.

would someone here be able to machine the 3 gears out of metal and possibly make more sets to help others? i dont mind paying for you services unless its crazy expensive to do this...i have no idea what it cost to do something like this.

if anyone is interested in helping let me know please.

 

[superspec]

 

[Jim Johnstone]

Out of curiosity, have you looked around for metal gears that fit the bill? Machining tiny gears can be a big pain in the ***, especially with the equipment most home shops would have. If you can find a suitable gear in metal already made, perhaps it would be easier to modify it to fit, rather than cut one from a steel blank. Can you find out the gear specs, ie gear pitch, number of teeth etc.?

 

[superspec]

nobody has been able to find anything over the past 8 years and up until recently nobody new who the OEM was for the gears.

 

[Mike007]

I can't imagine being able to reproduce those gears for only a few hundred dollars. It's a lot of work. If it permanently fixes the problem, it might be worth it to pay more then the $300 to fix the problem permanently.

 

[superspec]

i wouldnt mind paying the few hundred if i could get several sets made. all of the "work"would be done in the design phase and the rest would be a cake walk. correct me if i am wrong though.

if anybody would be willing feel free to shoot me a price. im sure i could get a group of people to help cover some of it.

 

[Primered Thunder]

nothing about cutting gears is a cake walk. nothing.

 

[Conor]

emachineshop.com

 

[dockterj]

Does the same gear fail in the same place everytime? It may have been designed that way. If you replace the gears with something stronger something else (more expensive) may break.

 

[gt40mkii]

Of you do this, don't use steel gears, use brass or whatever material is softer than the worm gear on the motor. If you use steel, the worm gear will wear and you'll end up needing to replace the motor instead of the gear.

There's a lot of friction on that worm gear, which may be why these gears were Nylon in the first place.

 

[A_Pmech]

all of the "work"would be done in the design phase and the rest would be a cake walk. correct me if i am wrong though.

Yes, just like building a bridge. The office staff does all the "work" and the ironworkers do the "cake walk" 400 feet in the air on a blustery January morning in the snow.

 

[bp460]

If they are straight cut gears, cutting them with a wire EDM would be pretty straight forward. Once an initial set is machined and tested, A good wire EDM operator could stack material blanks and cut multiples easily and possibly unattended. Reverse engineering them and producing a detailed drawing or CAD file is the time consuming part. With an optical comparator or toolmaker microscope it wouldn't be that bad. Get all your friends on board and pool your money... then find a mold or die shop to help you out. And it will cost more than $300.

-Brad

 

[superspec]

when i said "cake walk" i was referring to them being done on a cnc or some other form of computerized machine and once the files is made it would be nothing more than loading material.

 

[gt40mkii]

if any of you are interesed in how gears are really made, Google "gear hobbing". Of course Nylon and other polymer gears are generally cast, but metalic gears are hobbed (though I suppose they could be broached, or milled, too.)

 

[tpwalsh]

when i said "cake walk" i was referring to them being done on a cnc or some other form of computerized machine and once the files is made it would be nothing more than loading material.

Load the material. Then write the check for the tooling Then write the payment check for the machine, then write the check for the material.


Not much labor there, just lots of capital.

 

[Jim Johnstone]

Yeah, like others have said, gears are not a cakewalk at all. To get gears hobbed you can expect to pay quite a sum of money for setup, especially on small gears. I can't imagine anyone in a home shop having a gear hobber, which would mean cutting them manually, which would be a MASSIVELY time consuming job. I've cut gears manually one tooth at a time, and it aint fun.

Wire EDM would be an excellent alternative, but expect to pay a chunk for that too, as you won't necessarily find a wire EDM in your average machine shop. I still think finding out the pitch, tooth count, diameter etc, and trying to find an off the shelf gear, then having a machinist broach the holes, turn the shoulders etc. is the way to go.

 

[superspec]

**** it, seems like ill just keep the damn thing closed haha. i would hardly use it other than in the summer to vent the heat...in La. the sun beating down on you when its 115* just aint gonna cut it anyway.

 

[superspec]

Load the material. Then write the check for the tooling Then write the payment check for the machine, then write the check for the material.


Not much labor there, just lots of capital.

i meant no disrespect, i know that and decent size CNC will cost more than ill make in a decade.

 

[Jim Johnstone]

i meant no disrespect, i know that and decent size CNC will cost more than ill make in a decade.

It's not just that a decent sized CNC is costly to acquire and run, it's that a run of the mill 3 axis CNC milling machine is pretty much useless when it comes to gear cutting. You are getting into specialized machine territory. Machines like hobbing mills, or a 4 axis CNC, lathes with live tooling, wire EDM etc. Again, all stuff that an average machine job shop isn't guaranteed to have.

 

[mrpowderkeg]

I wonder if the gears could be cut on a water jet, then machine the rest of the gear? It's not like this is some rocket science, a friend made a small gear with a file and a ton of time once... it worked and works today

 

[remileblanc]

I could probly make them for less than 300$ per set. But i would need to sell at least 10 sets guarrenteed.

 

[superspec]

the tops look simple enough but the bottoms are where the machining would have to be done...i think ill just scrap this idea and not use the sunroof. i didnt buy the car because of it so if i cant use it then its no real loss.

 

[superspec]

I could probly make them for less than 300$ per set. But i would need to sell at least 10 sets guarrenteed.

is that 300 per set or 300 for the first set and then maybe 100 for the other nine? i know good and well i cant get 9 others to pay 300 for each set but i would be willing to do it for the first set.

just to put this in perspective, this is for a nissan sentra so we arent dealing with people with a bunch of disposible income

 

[superspec]

opps, just re-read it and saw the 300 PER set.

 

[remileblanc]

i imagine i could probly do around the 200$ per set ballpark. I would need to have a sample assembly shipped to me for a more accurate quote however. the more sets the less money they will cost to make. I would need to make at least 10 to hit that price.

 

[TommyD]

Take them to a casting/pattern shop and see what they say about casting them in brass, bronze or aluminum. Sand molds are pretty simple and they can cast some pretty intricate shapes. I've seen all manner of pieces cast, especially before all this plastic **** started.

 

[Mike007]

I could probly make them for less than 300$ per set. But i would need to sell at least 10 sets guarrenteed.

I'd like to know how you would make them? Sounds interesting.

 

[remileblanc]

I'd like to know how you would make them? Sounds interesting.

the old school way. gear cutter on a mill and a dividing head.

 

[steel 35]

I wonder if the gears could be cut on a water jet, then machine the rest of the gear? It's not like this is some rocket science, a friend made a small gear with a file and a ton of time once... it worked and works today

I was wondering if the water jet could do it all....

 

[EdT]

If you google "custom gears" you will find that there are a lot of companies that specialize in custom gears. I have cut gears on a mill with a dividing head and it's not too fun. These appear to be simple , straight cut gears and you might get lucky and find that they are some stock size as suggested above. It looks like the worm is a spring on the motor shaft and that the gear meshing with it is just a plain straight cut gear so it's not too sophisticated and it only runs occasionally so wear is not too big an issue. The first step would be to have someone who knows how measure the OD and count the teeth and you gac figure out wht module they are. They are probably metric. From that it can be determined if they are standard or "special". Odds are they are not standard, but you cant tell until you know some of the dimensions.

 

[afazz]

Generally worms mesh with throated worm gears. Sometimes they can mesh with helical gears, since worm gears are basically a helical gear with a throat. If those are truly helical gears, not just spur gears, that makes it tricky. If the OEM design involves a straight cut plastic gear in mesh with a steel worm, that sort of **** will likely not fly if everything is changed to metal.

Stock Drive Products probably has something standard that will work. Also check Berg and Nordex.

 

[rsanter]

Several comments

Nylon or plastic gears are used for several reasons including safety, they will break if someone gets their hand, arm, head or whatever trapped in the thing to prevent further injury.

I would look at making them out of plastic but a solid stock that you could machine including using a router copy type lathe setup and then do final lathe work for the other features

Look at getting a rapid prototype done, some can make some really good items that can be fairly durable for this use

How about you take that gear out and fix it with some epoxy....them use that to make a silicone mold from that gear.
Use that mold to make new gears out of a durable epoxy resin, save that mold and you could keep mskin them as you need them

Bob

 

[superspec]

primered thunder

no i do not, i have never been up close to one or seen what is involoved other than seeing stuff made on tv and watching "how its made" on history channel.

 

[Ron Lombardo]

These gears a injection molded ..find a co to produce them in a stronger polymer or fiberglass ... even cast aluminum would be less costly them machining them out of steel ... my 2 cents.

 

[bobadame]

I haven't read the whole thread. Maybe someone has suggested this already.
Measure the major diameter of each gear. Count the teeth of each gear. Search the internets for something called pinion wire. Buy this buy the foot. Part the individual gears in a lathe to the proper thickness. Bore a hole in the center of each gear blank the right diameter. It's pretty much that simple.

 

[98TJ]

Delrin would work in that application.

 

[Jim Johnstone]

These gears a injection molded ..find a co to produce them in a stronger polymer or fiberglass ... even cast aluminum would be less costly them machining them out of steel ... my 2 cents.

Are you suggesting he get them moulded out of a stronger polymer? If so have you ever priced out a mould? I design moulds for a living, and I would suspect something that size and simplicity could be a $10 000 mould.

 

[Capt Chrysler]

In a past life dealing with automotive. I would bet you have other problems and the gears become the weak link.

With that said!

I think you could wire edm them. (I have had a lot of "weird stuff" wired.)

Or ck out these folks. I talked to them at the Shot Show last month in Vegas.

prometal.com

Capt. Chrysler

 

[machine_punk]

I don't know about your specific situation (i.e. the 'Nissan Sentra' sun roof motor/gears), but I have done a lot of troubleshooting on mechanical systems in the past. This sounds like you are looking at the gears as an isolated system...and they are NOT. They are part of a WHOLE system (The motor, the gears, the window, the track, the part which pushes the against the window, etc.) If the gears are failing, it is entirely possible that it is because the rest of the system has a problem (the window is binding somewhere and putting more stress on the gears than the engineers designed them to handle).

Before spending a lot of money on new gears, I would look hard at preventive maintenance for the whole system:
- Is the system in proper alignment?
- Has there been damage to the system? (bent rails, worn out/out-of-place rubber seals)
- Is the system lubricated properly?
- Are the tracks clean and free of debris?

Another part of the system may be 'out of specifications,' and causing a failure to the gear system. I would recommend taking the headliner off and inspecting the system in depth--that may save you some money in the long run.

D_P

 

[superspec]

I don't know about your specific situation (i.e. the 'Nissan Sentra' sun roof motor/gears), but I have done a lot of troubleshooting on mechanical systems in the past. This sounds like you are looking at the gears as an isolated system...and they are NOT. They are part of a WHOLE system (The motor, the gears, the window, the track, the part which pushes the against the window, etc.) If the gears are failing, it is entirely possible that it is because the rest of the system has a problem (the window is binding somewhere and putting more stress on the gears than the engineers designed them to handle).

Before spending a lot of money on new gears, I would look hard at preventive maintenance for the whole system:
- Is the system in proper alignment?
- Has there been damage to the system? (bent rails, worn out/out-of-place rubber seals)
- Is the system lubricated properly?
- Are the tracks clean and free of debris?

Another part of the system may be 'out of specifications,' and causing a failure to the gear system. I would recommend taking the headliner off and inspecting the system in depth--that may save you some money in the long run.

D_P

i have thought of that and other than maybe the lube breaking down i dont really see any other problems. my sunroof has only been opened a hand full of times in its life because its always either to hot or to cold here...we seem to have very little "just right" weather. also this isnt just in my car or a few others. this has been an ongoing problem for years.

ill pull the headliner this spring and check it out since im recovering it anyway but i may just say screw it and leave it alone.