anybody here willing to machine some gears?

[machine_punk]

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.

Sounds like you have checked most of the rest of it...there is, of course, always that possibility that it is just a poorly designed system.

 

[slopecarver]

A plastic extrusion mold would likely be cheaper than an injection mold, not sure if it would be cheap enough. You could crank them out by the feet for dirt cheap after the mold was made, probably using a wire EDM method as just a solid part. The hole drilling would be a secondary process in a lathe much like the "pinion wire" mentioned earlier.

Another option is DMLS (Direct Metal Laser Sintering) which is a method of rapid prototyping/3D printing. A whole sheet of gears could be made in a day, probably 30 sets for $1000 total (just a guess) Costs example: Linky

Additionally you could use a standard additive 3D printing process with a binder and metal powder then have the very fragile powdered shape sintered at a total cost of $8/cc, maybe $50 per set given the size of those gears. Linkly

 

[AndyL]

Or just draw em up in sketchup then reprap them... the abs might be weaker - but the replacements would be pennies

 

[Dick in Wisconsin]

As one of the posters said, there might be a good reason why gears at nylon. Are you sure everything else in the sunroof is adjusted right and not binding. Everything lubricated right? If there is a lack of lube or something is binding, then the gears are going to take the brunt of it. The little I know about machining, a worm gear needs to be "hobbed" and this is difficult and requires specialized equipment. We have sun roofs in our cars ... and I don't use them.

Did I tell you about the time we were in Charlie's brand new Mercedes S500 after the Brickyard 400 and I opened the sunroof? We were driving down the alley just south of 16th Street between Georgetown Road and Lindhurst and a horrendous thunderstorm came up and I couldn't get the sunroof to close ...

 

[kartracer55]

If these gears are failing, it is because there is something else going wrong with the sun roof. They wouldn't be designing these things with margins low enough where they would be failing under normal conditions.

My sun roof sticks, I grease it now and then, as I crack if often when I park my car on summer days.

 

[Kevin54]

All you need to do is reverse the process. You need a good set of gears to begin with. Pour a mold off of the good set of gears. Send that mold to a Rapid Prototype place that does "investment castings" and have the gears made out of aluminum. If the center is left solid, you can chuck up on the OD of the hears in a lathe to bore the center hole, then have them broached. I would say for less than a grand you could have 10 sets made.

Do a search for "Investment Castings" in your area, give them a call and get a quote. Explain to them that you work at home and are looking for a way to repair your gearbox. Most places that do Investment Castings will work off of your mold or they can easily make a mold of their own. How they do it is once they make a simple mold off of the gear, they them pour the mold with a wax. This wax is then sprayed multiple times with a ceramic slurry. The ceramic slurry is cured and the wax is them melted out. You now have a ceramic mold. The ceramic mold is then poured with a molten aluminum. Once that is hard, the ceramic cast is then put into a tumbler that breaks up the ceramic leaving you with the aluminum castings.

Another alternative would be to have them done on a SLR (Stereolithography) machine. They can do this with different plastics. It uses a laser to build the gears up. The laser hardens the plastic as it makes passes across. The gears could be made complete. What the company that does that would need is a blueprint of the three gears in question. Again, do a search for Stereolithography. I know that on TV on the Mother's Car Shows where they always show the different companies and advertisers, one of the advertisers that is always on there does the Stereolithography or Rapid Prototyping for car parts. What I don't know is the name of the company.

 

[MBeaty]

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 think that this is the route to go. These gears would not have to be super hard or precision made in comparison to many gear applications. I had a friend who owned a water jet machine. It had some built in software on the CAD side to generate a gear profile based off the pitch and number of teeth. I would think that a water jetted gear would hold up in this application and should not cost too much to make.

The surface would not be nearly as nice as a hobbed gear, but the cost would be significantly lower and I doubt the gears need a critical finish on them.

 

[antinym]

http://www.bostongear.com/

they probably have it. expect to pay around $40-80 per set.

 

[bobadame]

pinion wire, make a bunch for cheap.

 

[eno(1)]

check out those battery powered kids toys that they ride in or on. These things are thrown away when the batterys or charge controls fail but the ones with gears may work for you I never found one with bad gears check out the trash on trash day and garage sales

 

[kmacht]

Do you have a 2d cad drawing of the gears? I have a cnc router that I could try making them out of some harder plastic on. As long as the teeth are straight and the bottom of the gear tooth can be slightly rounded it is a pretty easy setup.

Keith

 

[jweller]

If these gears are failing, it is because there is something else going wrong with the sun roof. They wouldn't be designing these things with margins low enough where they would be failing under normal conditions.

Never had the "pleasure" of owning (or a fiancée who owned) a Nissan Sentra I take it. Hers got 4 catalytic converters and a new motor before 75k miles, and thats just the big stuff. Calling it a total shitbox would only give boxes of feces everywhere a bad reputation.

Or just draw em up in sketchup then reprap them... the abs might be weaker - but the replacements would be pennies

This is the winner! you can buy that machine for $3k or so. and print as many as you could sell.

 

[superspec]

jweller

was it the 2.5 motor? ive never heard of any other nissan motor being that bad.

 

[jweller]

jweller

was it the 2.5 motor? ive never heard of any other nissan motor being that bad.

Yup. 02 Spec-V. Check the gas, fill the oil.

To be fair, the car was a hoot to drive, when the mechanic didn't have it, and got 32mpg while you beat the piss outta it. It also burned 3qts in 1300 miles of an oil consumption test. Awful factory paint, and more rattles and squeaks from the dash than you could count after about 35k or so.

I would have liked to like that car, but in the end, it was garbage.

 

[superspec]

haha, i guess it just takes a certain person to love that car. personally i own 2 spec-vs i have a silver 02 and a silver 04. the 02 had the motor warrantied at 19k miles and the 04 motor lasted 120k when it was pulled but still ran fine. to be fair though the 02 has the only running destroked qr25. its 2.3 ltrs of fury spins to 9 grand turboed and made 500whp. the 04 got a motor swap and is now sporting a vq35de. i love both and plan to buy another one to do a built NA vq35 and stroke it to 4 ltrs.

 

[onuxis]

So, I have no idea if this would work for your application but...

Many years ago in junior high we were making 1.5 volt vehicles for a competition. Our instructor at the time showed us how to make/copy gears in a silicone form and use epoxy to re-cast the gear. Wasn’t perfect but it got the job done.

Not sure if epoxy would handle the load or last long but a quick search shows about the same process we used.

http://conradhoffman.com/HP8640B_gears.htm


OR even better....

Purchase a makerbot and get to designing

http://www.makerbot.com/blog/2010/11/23/pattywac-dueling-design-giveaway-winners/

http://thingiverse_beta.s3.amazonaw...4e/4130791241_3a1132b5aa_o_display_medium.jpg

 

[cnc-me]

What about replacing the entire gear case with something stronger.

 

[Jack Burton]

I think what's wrong is apparent in the OP's pic. The gears are meshed too tightly. It looks as if the housing shrunk or the gears expanded. One nylon gear is a safety device, multiple nylon gears is cheap poop.

Did you check out http://www.sdp-si.com/

 

[gorilla]

Trash the Jap ****, buy a real car and you won't have the problem.

 

[JamieK]

Design it out at emachineshop.com, and submit for bids.

 

[red92s]

You can get parts rapid prototyped in materials that will approximate ABS and nylon. I'd guess that the first part would be $50, with additional copies made at the same time around $15.

DLMS, as previously suggested, gets really expensive really quickly.

http://www.finelineprototyping.com/

 

[chad99]

Has the vehicle been in a wreck?even what you may consider to be a minor fender Bender can manifest itself in strange ways with today's full unit body type construction.Nylon and various polymer gear sets have been used for decades,without catastrophic fail rates for low torque applications.If you are consistantly shearing gear teeth the answer is to correct your binding linkeage or frame not to construct.steel gears so the.whole assembly can further self destruct itself.

 

[superspec]

no wrecks. its a fairly common problem for this car.

not a big deal, ill just keep it closed haha. i have 2 of these cars and the first one i bought new and refused to have a sunroof. the 2nd was bought used from a friend so i know its history.

 

[Okie Pete]

Check around and look for a shop with a plastic printer. A friend showed me a turn buckle with hemi joints for ends that was sent to his employer as a demo piece. The hemi balls moved . It had lefthand and righthand threads that worked. They can also spray other materials also.

 

[andywander]

Is it always the same gear that breaks?

I might be able to machine a few of those....

 

[superspec]

in the set that i have there are 2 gears broken.

 

[68rustang]

do you have a CAD file or are you expecting somebody to do all the work if you send the gears?

Being it is just a sunroof it shouldn't be too hard to get something serviceable without going crazy.

 

[superspec]

i have zero in the way of files and only a set of gears which 2 of the 4 or 5 are missing teeth or cracked.

 

[andywander]

"...4 or 5"? I only see 3 gears(not counting the worm) in your photo.

 

[superspec]

there is one under the top gear next to the penny

 

[RobSmith]

get onto "Model Engineers Workshop". They're in England and their hobby involves making machines and tools for their workshops..gear cutting is 'just another job' for them. They like fitting computer controls to their machines as well.

 

[fastbroshi]

I'm late to this party, but you can cut gears a lot quicker on a lathe with a Hardinge dividing head and some cutters. Don't see them much anymore so it's not surprising it hasn't been mentioned. Here's a quick walk through. Hell, maybe the author could do it for you.

 

[stioc]

If nylon/plastic is OK contact this guy, that's what he does: http://www.odometergears.com

Here's the process of cutting gears at home which is not hard, just time consuming and of course you have to have both a mill and a lathe - or a combo machine:

 

[SVE Performance]

Try here http://gearsmade.com/ .Bill