Axle gear not secure on NWSL axle

Return it and ask for a replacement.

Regards,

Ed

What to do?  Did you call them first?

In My experience they are a first class operation and stand behand any problems.

IMO, posts complaining about a product b/4 giving the mfg. a chance to make good does not serve the hobby very well.

As a matter of fact. NWSL custom installed about 160 2 rail axel sets in MTH captive passenger trucks for us.  One did not run true and they had it replaced and in my shop in one week.  They do not deserve a bad rap in my opinion.

Anybody can run a business, only excellent  companies respond promptly to issues.

Nope. Knurl the axle.  Come on, Harmon - all it will cost is postage.

I love the NWSL products.  Without my dealer discount (thanks, Raoul, for all those years with a 40% discount) I no longer have a large stock.  I will not build up a locomotive without using the Mod 0.6.  And my tender drives use their large horney ball U-joints.  They even made wheelsets for me - the .172 scale steel wheelsets.  Raoul was going to name them after me.

So in the beginning I wanted to use the brass RWG, since it could be "Loctited".  But we found out that brass axle gears last about two hours.  By the time we switched to bronze, I had the knurl perfected.  In fact, if you buy a Babbitt steam locomotive with the NWSL gears, the chances are excellent that the axle went through my shop.

Already way beyond what you wanted to know - but I got together with a Loctite engineer, and we decided to attempt a solution.  He got me a discounted small quantity of "Type N" prep fluid for only ten bucks an ounce, and I gave it a test.  It simply does not work on Celcon acetyl plastic.

That's my story, and I am sticking to it.  Like old loctite.  Like glue.

The instructions do not mention the need to knurl the axle - if it is necessary why didn't they do in the first place?  I did contact NWSL and eventually linked up with Oso Rail Works and had one communication with them.  Maybe the Holiday prevented any further communication.  As far as the ball type u-joints I am not happy with them either because they rattle.  Erik Stott is going to send me some of his.  bob2, is your knurl 1/8 inch wide?

I should have said there is no mention in the instructions of the need to knurl the axle.  If anyone else made a gearbox for a 5.8mm. axle I'd replace the NWSL in a heartbeat.

Harmon,

Bob Turner and I will disagree on this because he prefers the NWSL non idler gearboxes for their low profile.  I never use them because of the plastic axle on the driver shaft.  I use the idler gearboxes that employ a brass axle gear running against the Celcon idler gear.  You can Loctite the brass axle on the axle and you are finished.  If I did install a Celcon gear, I would either knurl the axle or, using an automatic center punch, put some small dimples in the center of the axle around its circumference.  That should hold the Celcon gear for you.

Joe Foehrkolb

Best advice.

I had an issue with a new gearbox and rather than create more problems and frustration, I returned the gearbox with my wheelset along with a detailed note.  The gearbox was returned assembled with flawless performance....at no charge.

Absolutely top notch service. 

Thanks for the suggestions.  Joe, thanks for riding to the rescue.  I think I have an automatic center punch (which I have never used).  I have thought about using a narrow sharp chisel and making parallel raises to knurl in that fashion but the center punch will work as well and probably easier.  Joe, I know you deal with many different kinds of gearboxes - one is as good as another?

Happy Thanksgiving Everyone

Harmon,

Just curious, what is the hole diameter in the axle gear?

NWSL offers the mod 0.5 gearbox for a variety of axle diameters.  Did you order the correct gearbox?  If so, and the gear is incorrect, NWSL should make it right.

Otherwise, your info is a bit suspect. 

Harmon,  I use quite a few NWSL ball bearng gearboxes in my shop, both 0.5 and 0.6 depending on the size of the model.  They seem to hold up well and are readily available.  I really like US Hobbies gear boxes but they are becoming hard to find and those who do offer them for sale seem to want quite a bit for them.  ALso they are not availiable in various axle diameters like the NWSL boxes are. 

 I also have some Pearce ball bearing gearboxes that are very nice and a small assortment of Lobaugh gearboxes that I find to be more difficult to install than most.  However, properly installed, the Lobaugh ball bearing gear boxes with the Micarta worm gear are very smooth and quiet.

If you try my trick with the automatic center punch and you have a drill press vice with good parallel jaws, open the vise jaws up to about 1/8" and lay the axle to be punched in the jaw opening.  This will support the axle while you punch the dimples around the center.

Regarding the comment about the correct size of the axle, I have found variances in steel stock that, although it may be only a thou or so, will effect the fit of a wheel or gear when installed.  I am sure you have the right gear.  Anything else that NWSL offer would either not go on (too small) or flop around on the axle (6mm or 1/4")

Best regards,

Joe Foehrkolb

Joe,  How did Lobaugh using a Micarta gear secure it to the axle?  I'm a little surprised to hear you say NWSL axles may vary in diameter - they told me their axle stock was better than drill rod because it was ground to dimension from 12L14 steel.  It does machine well which I like.

Regards to you as well

  I know some people on this site think I'm ungrateful to NWSL but when you have a steam locomotive mechanism completed and you discover the gearbox is failing, the smile goes off your face.

The other option is to install a brass bushing in the offending gear.

Take said gear, bore it (for the sake of this explanation) to, .2498", machine the bushing to .2500" OD and 5.75mm ID.  Apply straight knurl to outside of bushing, press bushing into gear, install gear onto axle.  Now you can use Loctite.

I also avoid using the Delrin gear on the axle.

Jay

Harmon,

NWSL doesn't make their own ground shafting.  They buy it and, just like the rest of us, they are dependent on their suppliers.  I won't use drill rod because, believe it or not, the tolerances for drill rod isn't as tight as precision ground rod & it's a higher carbon steel so it's much harder.

I did get a batch of .125" shafting from them that actually miched out @.1235".  Could use it so I returned it.  Turns out their supplier sent them an entire shipment that was not in the required tolerance.  

As a side note I now buy my 12L14 (Ledloy) from Alexandria in 6' lengths.  Here's a link, http://www.alexandriaprecision.com/index.html

I'll tell you what, you pay the postage, both ways, and I'll fix your gear/axle for free (one time offer).

Jay

Thanks for your offer, much appreciated.   I'm capable of knurling the axle, but I'm cranked because apparently I'm not the first to have to deal with this problem.  It would have been most helpful to mention this in the instructions.  Save a lot of headaches if installers were given advance notice. 

Harmon,

Lobaugh gearboxes incorporate a Woodruff key to hold the Micarta gear from spinning on the axle and the brass gearbox is so narrow that the worm gear cannot slide along the axle's length.  If you wanted to you could Loctite the Micarta gear but because of the Woodruff key it is not necessary.

I did not say the NWSL shafting was out of spec but from another post above it sounds like they have had such problems.  Even when I convert a multi axle diesel truck to 2 rail, I often find that some wheels press on the original axles tighter than others.  All of my conversion wheels are drilled and reamed with a precision reamer on the lathe so I expect it is the axle stock used by the manufacturer.

Did you check your axle diameter with a good micrometer? 0.001" will make a difference in a fit like this.

Joe

Harmon,

No problem.  Just beware, make sure the knurl is straight not a cross hatch pattern.  The other problem with knurling is making sure it doesn't extend beyond the gear.  If it does it will eat the gearbox axle bearings. 

Once a gear has spun on the axle it's more difficult to fix.  Once again, if using a engineering plastic (Delrin) on the axle, I prefer using a collet to hold the gear while I bore it with a miniature boring bar.  I much prefer this over reaming (just a personal preference).  After boring to size I insert a bushing and bore it for an interference fit onto the axle.  You then end up with metal on metal press fit.

Don't be too hard on NWSL they make great products but, just like any other supplier they can something slip through periodically.

Jay

I too have found axles that are out of spec - my first scratch locomotive - the MM-2 in 1985 - has Max Gray axles, and one was slightly smaller than the other.  Right then and there I learned about axle slip.  I knurled both axles, and have done so ever since.

Woody and I did some testing - he was able to break the bond between axle and gear by throwing the reverse switch at speed with a very heavy locomotive, and will not use NWSL components after that test.

If you really want to use Loctite on the axle, Jay's idea is the way to go - but I note that it is almost equivalent to knurling the axle.  I say almost, because Jay's idea gives you more surface area, but also weakens the gear slightly.  

A straight knurl is lots better than a bunch of center pops - that is because the grooves the knurl puts in your gear are all in contact with metal.  And yes, my knurl is straight and the width of the gear.  It is not perfect, but I have never had a failure.

To Joe and Jay - we have this conversation often enough, I guess.  I have this "thing" about boiler bellies, and about extra friction.  It is the same kind of "thing" that I have for plastic models - just me and my version of the hobby.  The extra friction of the idler gear is negligible, but since I have no axle slip, I do not need even that small, negligible friction.

But if you absolutely need a metal axle gear, NWSL has a bronze reverse worm gear and a reverse worm. These can be used in the Mod 0.5.  I do not know if they make the reverse worm for the Mod 0.6.

And again, only personal experience over a quarter - century:  I routinely replace Lobaugh, Max Gray, and USH gearboxes with NWSL.  I carefully save the more valuable gearboxes, often stuffed into the boiler with notes to the future owner.  Just me, but I get far quieter and better looking models this way.  The Pittman 8000- series motors are also my standard, although my first two orders (40 motors) were 9434s.  Just personal experience.  I do not spend a lot of time watching trains run.

To the airport . . .  I have it to myself this afternoon, and plan to practice engine failures on departure.  Yippee!

Harmon,

If you have the CORRECT axle gear and axle, it will be a press fit...as the NWSL instructions state.  If you were sent the incorrect part or ordered the incorrect gearbox for your loco axle, I am confident that NWSL will make it right for you.

Even if you butchered something during assembly, READ the note on the last page of the NWSL gearbox assembly instructions titled: DISASTER

Stop whining....and Happy Thanksgiving.

It is a press fit but not enough interference to stay secure.  As far as my "whining" as you put it, if I was producing a model gearbox it would work. No excuses, Period.  Happy Thanksgiving!

Harmon,

If that is the case, then take the advice listed above by Ed Kelly.

It's only fair that NWSL inspect the parts to avoid a potential problem...and save other modelers the frustration that you are experiencing.

Seems simple enough.

Let us know the outcome.

Thanks.