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Need a 127 tooth gear

Illinoyance

Stainless
Joined
Aug 24, 2015
The metric change gears were missing from my Nardini lathe. I need a 127 tooth 1.5 mod gear. Not sure about the pressure angle but I am assuming 20*. I can cut the gear using my rotary table and calculated angles for each tooth. It would be a long boring job. Does anyone have experience waterjetting gears? The blank will be about 5/8" thick.
 
Just get at it, and it will get done. Waterjet is pretty crude when cutting something that thick. The jet doesn't turn corners well and you get all sorts of uncontrolled gouges on something that thick. And it is rough to boot.
 
How fast do you need it? We are making some 1.5Mod gears shortly, and make 127T fairly regularly. Have to make a 128T 1.5M shortly, so could do yours right after. Won't be for a few weeks though. Feel free to email or PM me.

Best,

ZK
 
Sorry Zahnrad, didn't mean to take food off your table.

Not at all, buddy. Even I tell customers and friends when it's obviously time to go shopping. For onesies like this, none of us can compete when the other guy is making them by the hundreds or more. Simple and basic economy of scale. A good deal is a good deal.
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If your RT has provision for hole circle plates, you could make a 127 hole circle. The worm gear in the table acts as an accuracy amplifier so you can have fairly large errors in that shop made plate and they will be reduced by the worm ratio: 90:1 worm would mean that the errors in your gear would be only 1/90 of those in the hole circle. 40:1 worm would reduce them to 1/40.
 
Just get at it, and it will get done. Waterjet is pretty crude when cutting something that thick. The jet doesn't turn corners well and you get all sorts of uncontrolled gouges on something that thick. And it is rough to boot.

5/8" is actually not that thick. I was getting quite a good cuts even on 2" steel. And I did cut gears on a watrejet. Most machines have quality settings and on the higher quality the cut is slow but nice. And it does take a little tweaking with all the other waterjet parameters. The gear will not be as perfect as cut gear, but quite adequate.
 
How fast do you need it? We are making some 1.5Mod gears shortly, and make 127T fairly regularly. Have to make a 128T 1.5M shortly, so could do yours right after. Won't be for a few weeks though. Feel free to email or PM me.

Best,

ZK

Not a big hurry. It is on my to-do for within a month or so. Any idea on price?
 
I’m looking at a Nardini lathe Monday night. I will need the same gear if I purchase it.

I imagine there are more Nardini owners out there with the same need. I did find a Chinese source for the 40 tooth gear I need. It might be crap bur for $11 it is worth a shot.
 
Not a big hurry. It is on my to-do for within a month or so. Any idea on price?

Seriously consider the gear that Sami linked to. That said, if you still want to investigate our making one for you, I'll be happy to assist. Price just depends on a few things like whether you make the blank, or we do. How much work needs be done, does it need an arbor, etc... I tend to bend over backwards to help other PM members when possible, so I'm sure that you will be happy either way. Feel free to PM or email if you do not end up choosing to purchase one of the commodity ones.
 
FYI i manually cut my 127 tooth gear, 5/8" wide moly filled nylon. Bridgeport mill and a 6" rotary table, no division plates, all just done of a table from excel showing 360 divided by 127 in hours minutes and seconds. Each tooth and setting was triple checked, marked off and then cut, not fun but only took about 2 hours.

Sure they may be minor angular errors, if you can measure that in a thread cut on the lathe this is going on, good on yah, its a problem i don't have! Coarsest metric thread i have cut to date is 4mm pitch, the lathes imperial lead screw is 6.35mm pitch aka 4tpi. the 127 teeth im confident are way less than 1/2 a degree out just by looking at them on the simple theory each tooth and gap is roughly just under 3 degrees wide, 1/2 a degree out would be very very obvious! Do to how gears are, any minor error is not added accumulation wise to the thread as a additive lead error, but naturally corrects - over each turn of the gear (how ever much error bettwen tooth 127 and tooth 1 every turn tooth 1 is exactly 360 degrees right? so it matters even less in practice. My rough maths puts a 1/2 degree error at about 5 microns error on a 4mm pitched thread. Im confidently bellow that 1/2 degree and a less than 2 tenths error on the coarsest thread i ever cut does not matter and would be even less error on any finer thread.

Hence yeah, its boring and cutting a 127 tooth gear manually indexing there's well 127 things to get right! Nothing a little paranoid triple checking won't catch. But hey its doable and really not that bad. If i could have bought a 14dp 127 tooth gear for £50 though yeah that would be a obvious solution!
 
Seriously consider the gear that Sami linked to. That said, if you still want to investigate our making one for you, I'll be happy to assist. Price just depends on a few things like whether you make the blank, or we do. How much work needs be done, does it need an arbor, etc... I tend to bend over backwards to help other PM members when possible, so I'm sure that you will be happy either way. Feel free to PM or email if you do not end up choosing to purchase one of the commodity ones.

I did go with Sami's link. It is one of those things that I don't really need right away---But I want it now.
 
(I vote for buying the gear above but am writing the following for reference) We've cut lots of gears on waterjet and they work fine. There's a nice gear maker in the OMAX software so you can whip them up in a flash. Our machine doesn't have tilt compensation though so you get the .0025" taper that is pretty much independent of thickness. What this means for gears is it's best to cut them in pairs and install them cut-site-up against cut-side-down, so the tapers are complementary. I'm sure it would work ok against machined gear, at least after running in a bit.
 








 
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