Replacement worm wheel gear for Samhongsa Brass F3

[genemaddox]

Jason, I was reading about your problem on the tower gears on you F3's, I have Samhongsa Factory gear replacements, mine are all brass and come assembled together ready to install. The large gear in that tower is 14 tooth and is pressed onto the small gear which is also a 14 tooth, if you want them let me know, I only have 6 of those gears left. If 4 of your gears are cracked, you should replace all of the gears in the 3 locomotives, you can email me at dmaddox@tx.rr.com, my name is Gene Maddox

[genemaddox]

This post is for anybody that has a brass locomotive with cracked gears in the tower, if you go into the webside Spookshow.net I believe, when you open the front page you will see "N Scale Brass Locomotive Gears" on the bottom of the page, click on that it will take you to a chart I created years ago while working at Bobbye Halls Hobby Shop/Hallmark Models in Dallas Texas. This chart will show you what gears you need to fix your problem. Column 6 is in bold print and the teeth it shows there is the gear you need, Colum 5 & 6 are combination double spur gear set that comes assembled, if you need to know more you can email me at the email address above the chart on the website.
Gene Maddox

This chart is for the Samhongsa drives mechanism only, Samhongsa made brass engine for Hallmark Models,Oriental Limited,PFM,key and other I can not think of at this moment, but I have gears for any of the above manufactures.

[ChristianJDavis1]

Image credit @spookshow and @genemaddox .

[wcfn100]

Thank you Gene for your post.  New parts from NWSL are already on the way, but I will surely check with you if I have any future issues.

Jason

[mark.hinds]

Thanks to @ChristianJDavis1 and @genemaddox for their posts above, which have allowed me to correct errors in my earlier post.  Although the NWSL 1042-6 package image I posted is correct for the Samhongsa micro-geared F-units, some of the supplementary information I included was not correct.  I have messaged the OP about this: 

<quote>
Hi Jason,

After seeing the table posted later in your thread, I went back and checked my gear stash more carefully.  I see that I have posted partially erroneous information.  I hope that you have not made an incorrect purchase based on this; if you have, contact me, and I'll compensate you in some way.     The errors are:

1)  The paired worm gear for the Samhongsa F3/F7, etc. should be a brass 14-tooth machined on a brass sleeve with a nylon 14-tooth (not 23-tooth) gear press fit on it.  So my sketch diagram is not precisely correct for the F-units, but instead applies  to one of my Samhongsa GP-9s, which do have a paired 14/23-tooth worm gear.  However, my posted image of the NWSL 1042-6 replacement gear package should be correct for your micro-geared Samhongsa F-units, so if that is what you ordered, you should be good.  You can see this if you look closely at my image, as the black nylon replacement in fact has 14 teeth (...). 

2)  Although the NWSL replacement gear package I photographed does show the replacement gear mounted on the brass sleeve, on further examination the other three I bought contain only the black delrin replacements.  It is therefore likely that 1042-6 contains only the delrin replacement, which presumably needs to be press-fit on the original paired worm gear assembly. 

Sorry about that; MH
<unquote>

MH

[genemaddox]

Also notice on the Gear chart that on all of the double spur gears (column 5 & 6). Column 5 is the smaller gear and all of them are 14 teeth. I have never found a locomotive with a different count on column 5. It is Column 6 the larger gear that changes the ratio. I made this chart many years ago and lord knows I may have made some mistakes. When you tear down this many locos and count the teeth on each gear sample, you tend to get a bid cross eyed after a while, so if you have any changes, let me know and I will see if Spook show can make the changes. thanks, gene maddox

[atsf_arizona]

As many of us know, Gene Maddox once worked for Bobbye Hall, and Gene has a inventory of gear parts for these locos.   
Gene was certainly instrumental in providing me the necessary parts to repair my Hallmark DL109/DL110 and M190's.
Without Gene, I don't know where else I would have found either the expertise or the right parts.
I can certainly vouch for Gene's honesty, rare experience and knowledge in repairing these locos, and his willingness to help
someone who's sincerely interested.    I trust the following will help.   Thx Gene, for being there for us.

Here's that Spookshow.net webpage:  http://www.spookshow.net/brass.html 

On that page you can see the gear chart as well as the words below that Spookshow provided:

===========

  "Pictured is a replacement gear chart for N scale brass diesels. This resource was created by Gene Maddox (during his years working at Bobbye Hall’s in Dallas) and is provided here courtesy of John Sing (with Gene's blessing). This should be an invaluable aid to any N scale brass diesel owner in need of replacement gears (due to the infamous "cracked nylon gear" problem). Gene spent countless hours disassembling every model listed below - counting, measuring, and documenting the exact combinations of teeth, diameter, proper replacement size, etc.

As the chart documents, getting the right replacement gears for N scale brass diesels is far from straightforward. The combinations are much more varied than anyone might have suspected and are by no means standard from one model to the next. Because of this unique need, Gene purchased Bobbye Hall’s complete stock of Samhonga replacement gears when she closed her shop. He still repairs brass locos, and still has his complete stock of replacement gears available for purchase. These are all brass (as opposed to nylon) Samhongsa factory replacement gears, in the exact combination of teeth and gear diameter required. Where appropriate, Gene’s replacement gear is the complete compound gear set (since most of us don’t have the tools to do press-fitting on tiny brass gears).

Gene is happy to accept inquiries via email and can be contacted at dmaddox@tx.rr.com. He accepts PayPal and ships via USPS."

===============

[genemaddox]

John Sing, thank you for those kind words, I appreciate it, I hope you are doing fine?  gene maddox

[atsf_arizona]

Yes, Gene, still doing good (cross fingers, hope it stays that way).  In Venice, FL now.

Trust you are still doing well.  Stay healthy and happy.  We all *really* appreciate you. 

[mark.hinds]

(text deleted) ... so if you have any changes, let me know and I will see if Spook show can make the changes. thanks, gene maddox

Hi Gene.  FYI, the nylon (?) gear which typically splits on these engines is actually called a worm gear rather than a spur gear.  You can see the difference if you examine it under magnification, as the teeth are angled to mate with the worm (which is the screw-shaped gear mounted on the motor-driven shaft).  So if you have occasion to adjust the chart, you might want to change the terminology in column 6. 

Also, FWIW, I found that all of my Samhongsa micro-geared engines from the different manufacturers (Hallmark, Oriental Ltd, and Key Imports) ran at essentially the same speed at a given supply voltage, despite having different motors.  This, in my opinion is why you see the different number of teeth on the paired worm gear (a nylon? worm gear paired with a brass spur gear). 

Lastly, I am pretty sure that the machined delrin replacement worm gear supplied by NWSL can be press-fit on the brass sleeve by hand without special tools, due to it having a certain degree of flexibility.  I say pretty sure because the one I photographed earlier in this thread is on the sleeve, and I certainly had no special tools for doing this. 

FWIW, MH

[genemaddox]

Thanks for the information, I will see if I can get Spookshow to make a correction for me, I list the 2 gears (column 5 & colum 6) in separate columns but the gears I sell are from Samghonsa and that is the only way I sell them, mine are already assembled and are all brass. I guess the small gear is a spur gear because it drives the gear on top of the lower gear box and the large gear is a worm gear which drives the worm itself.

thanks again, gene maddox

[peteski]

Thanks for the information, I will see if I can get Spookshow to make a correction for me, I list the 2 gears (column 5 & colum 6) in separate columns but the gears I sell are from Samghonsa and that is the only way I sell them, mine are already assembled and are all brass. I guess the small gear is a spur gear because it drives the gear on top of the lower gear box and the large gear is a worm gear which drives the worm itself.

thanks again, gene maddox

A single gear that mates with other gears is a spur gear.  A gear which mates with a work is called "worm gear" or "worm wheel".  Two gears joined together are called "combination gear".  In this case it is a combination gear consisting of a worm gear and spur gear.  Most combination gears are permanently joined. In this case the confusion comes from the fact that the worm gear part of this combination gear can be remover or replaced.

[spookshow]

Thanks for the information, I will see if I can get Spookshow to make a correction for me, I list the 2 gears (column 5 & colum 6) in separate columns but the gears I sell are from Samghonsa and that is the only way I sell them, mine are already assembled and are all brass. I guess the small gear is a spur gear because it drives the gear on top of the lower gear box and the large gear is a worm gear which drives the worm itself.

Actually, John made that .pdf. Maybe he can amend it.

-Mark

[genemaddox]

Mark, if it is on your website per your permission and mine, how can John correct it? gene maddox

[spookshow]

Well, he sent me the one that's on my website, so I suppose he could send me another one which I could then use to replace the old one.

-Mark