It is currently Mon Mar 08, 2021 8:30 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 12 posts ] 
Author Message
 Post subject: wheel lathe cutting tools
PostPosted: Thu Dec 24, 2020 3:32 pm 

Joined: Sat Dec 19, 2020 4:56 pm
Posts: 2
I am a long time volunteer at the Southern California Railroad Museum,( formerly OERM) which is located in Perris, Cal. A highly motivated group of volunteer mechanics is rapidly closing in on the long term goal of restoring the museum's Niles wheel lathe to service in the museum's machine shop.
It was recently reported that the servicing and restoration of the lathe's electrical system has been completed. The lathe is now in state to begin the final tasks of the lathe restoration project. The completion of this project will enable the return of the wheel lathe to museum service. It may come to pass that the first 'real job' assigned to this lathe will be to restore the profiles of the badly worn driver tires of the Museum's VC-2 steam locomotive to 'spec profiles'. (The VC-2 is a 1922 Baldwin 2-6-2 logger.)I have taken on the task of procuring the cutting tools necessary for the work to be undertaken. It is believed these tools will be a type of 'form tool'. It is desired that these tools be made of Tungsten Carbide (for durability). The use of high speed Steel (HSS) is acceptable if carbide tools are not available (or too costly).
I am asking that anyone who believes they have information concerning tool design, vendors, or wheel repair useage, post this information on this forum. I believe acquiring such information is vital to the successful completion of my task!
I am also interested in any wheel lathe 'shop' stories that you may have. I am an old man now (88 years behind me and with the hope of few more to come) and I would like nothing more than to see the return of this machine to its intended and important role in keeping the museum's steam locomotives 'alive and well'. (Working to this end helps keep ME 'alive and well'!) Believe me, your help will be greatly appreciated!

We all want future generations of 'wide-eyed' young people to have the same opportunities to enjoy operating, maintaining, and riding 'real' steam locomotives as we now enjoy.
Mel Johnson, aka "The Old Machinist"


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Thu Dec 24, 2020 7:31 pm 

Joined: Fri Mar 25, 2016 12:23 pm
Posts: 21
Location: Western Washington
I would think the tooling for portable wheel lathes would be readily adaptable to the Niles Lathe. They offer several grades and shapes of carbide tooling for truing wheels with flats, hard spots, etc. See if Independent Machine Co can help you out. https://imc-info.com/

(note-I have no personal or professional connection/interest in IMC, though I have used their products for truing locomotive wheels on Diesels)

Josh


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Fri Dec 25, 2020 11:00 am 

Joined: Sun Jul 22, 2018 2:03 pm
Posts: 35
In 2004, I saw a note about Apex Tool & Cutter Co. from an active Wheel Lathe user.

Their current website shows railroad products at http://www.apextoolandcutter.com/railroad.html.

Regards,
Bob Milhaupt


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Fri Dec 25, 2020 11:10 pm 

Joined: Fri Mar 14, 2014 11:44 pm
Posts: 92
Hi Mel, we've met once or twice. I'm happy to hear that your Niles lathe is coming along. Is this the machine that is next to the barn that normally houses the VC?

We have a smaller Niles lathe here out east at Branford. I had some special AERA profile form cutters made by Apex which is now part of JEMCO. As it turns out, our Niles lathe then had some flood damage which took a while to repair and we did the project a different way, so the cutters have never been used. They were about $1500 each at the time, 5 or 6 years ago.

I would recommend taking as little of a cut as possible with the form cutter. Years earlier I observed as our retired master mechanic did a wheel job (standard AAR profile) and he experienced a lot of chatter and dulling with the profile cutter, even at the lowest possible speed on the lathe, which for our model is about 3 RPM. He did it dry which is apparently how the operators of the machine usually did it, but perhaps they were re-grinding their cutters before each wheelset? I would flood coolant.

Along these lines, it might make sense to use various round-nosed single-point tools to rough out the fillet. These machines don't have a compound rest but you could approximate the sloped side of the flange with a stairstep of plunge cuts. Then you'd have just a small amount of metal to remove with the form cutter.


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Mon Dec 28, 2020 8:29 pm 

Joined: Fri Aug 20, 2010 8:25 pm
Posts: 379
I admit I have never operated a wheel lathe. But I do have quite a bit of experience machining both new metals and "in service" metals that have been operating in rotating situations.

Problem with old loco wheels is they have been exposed to quite a bit of "work hardening". This occurs when you roll two metal surfaces together (tire/rail) for a long time. It can be quite uneven around the circumference of the tire/wheel with some areas quite a bit harder than nearby areas. This causes "chatter" and interrupted cuts were the cutting edge is pushed away from the work because the steel is too hard.

Both of these are "killer" situations for carbide tools. Carbides (in general) stay sharper longer than tool steels but they are brittle. Any rapid change in cutting force (hitting a hard spot) will break off the edge of a carbide tool faster than you can say "there goes a thousand dollars".

I would recommend against a carbide form tool, probably cost several thousand dollars and likely to get decimated during your first try at machining an old tire.

Also, form tools of any kind require a lot of horsepower (probably 10-15 hp) and complete rigidity of the machine tool, any backlash in a cross-feed screw, slop in the headstock bearings, or a lose gib and you will get chatter out the wazoo and a terrible surface finish.

In my experience "chatter" is almost always caused by the machine tool being "loose" somewhere (a bearing, feedscrew, gib, etc). You can sometimes get away from chatter by moving to different feedrate or rotating speed (which moves the "resonance" of a loose bearing in the machine away from the rotation speed of the part). Lubrication with a cutting lubricant can help sometimes, but other times it makes no difference.

I would start with high speed steel single point tools until you get a feel for how the machine operates. Yes, you may have to sharpen them a few times, but if you break off the tip you can grind a new edge in a few minutes.

Maybe use the carbide inserts shown in that Iron Horse video. Those look like a little tapered roller with the cutting edge up at the wide end of the roller. A screw goes down through the middle to secure it to the tool holder. At least you can rotate those a few times and get a couple of cutting edges out of one insert. Those are likely $10-$20 each.

My impression (only that) is that those form tools where used to finish machine brand new steam locomotive tires when the metal was "virgin" and had uniform properties and was already "nearly net shape" (IE already close to the final spec shape). Like a "finish cut" to finalize the tire shape.

Carbides are meant for production work where the material properties are uniform and well understood and the machine is designed and maintained to support carbide tooling. Carbide tooling did not really arrive in the machine shop until well after those wheel lathes were retired.

Just my 2 cents, hate to see you spend thousands on expensive tooling only to break it because there is something out of adjustment with the lathe.

Cheers, Kevin


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Tue Dec 29, 2020 1:56 am 

Joined: Fri Aug 20, 2010 8:25 pm
Posts: 379
To add just a bit to my prior post;

I would grind a couple of high speed steel "single point" cutting tools;

1 - A flat faced tool to match the pitch of the main thread of the wheel shape (14 degrees ?) Moving it "left/right" and plunging into the thread should cut the thread shape just fine

2 - A filet tool to match the "thread" to "flange" radius (1/2" OD ?)

3 - A flange tool to match the side angle of the flange (7 degrees ?)

4 - A "flange round over" "form" tool with an ID to match the desired end profile of the flange

That is about $50 in HSS 3/4" tool bits (assuming good quality Cobalt Steel). And an hour or so with a good bench grinder (keep the bits cool so you don't lose the hardness of the HSS)

Those and a couple of general purpose "left"/"right" bits to clean up the edges should be all you need.

I would work my way out from the thread to the filet to the flange to the round over portion of the flange.

Would take some patience changing out tool bits but it will give you some good feedback about the performance of the lathe itself.

A simple first attempt, I would try that first for $100 instead of dropping thousands on a form tool.

As I understand it the modern railroads have Computer Controlled Wheel Lathes that drive a single point tool using a hydraulic cylinder to "trace" the desired profile in the wheel tread. But they are profiling hundreds of wheel threads a month.

Good luck, Kevin.


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Wed Dec 30, 2020 1:32 pm 

Joined: Sat Dec 19, 2020 4:56 pm
Posts: 2
I want thank those who have responded to my Post (wheel lathe tools). What you have written in your replies is very helpful to us as we work toward the return of the wheel lathe to service. Your comments have kicked off several useful (and lively) exchanges of ideas and views concerning the path forward for the lathe project. I encourage others to chime-in; we want more ideas and stories about the subject of heavy duty lathe work.
Mel Johnson


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Wed Dec 30, 2020 9:45 pm 

Joined: Fri Aug 20, 2010 8:25 pm
Posts: 379
Mel, If I was returning a retired wheel lathe to service I would start out with a dozen of these;

https://www.victornet.com/detail/TBCO-3/4.html

Grind the ends to the "local" shape you need (thread, fillet, flange, edges) and "debug" the lathe first. Try turning a diameter and see how smooth it comes out (checks headstock bearing and crossfeed slide tightness). And try facing off a surface (checks headstock endplay). If that looks good I would move on to an actual tire thread (maybe an old freight car axle/wheel assembly).

If you have some other "test" piece that is about the same size as your final "product" I would try things out on that piece first.

(I have no affiliation with victornet, but I have been satisfied with the products I have purchased from them in the past). Note: they do clearly mark (US made) versus (Import). There is a discernible difference in quality/value. When I have a "one off" task that I will not likely do again in a decade I might opt for the "less expensive" option, with a little patience I can get the job done. If it's a tool I will use every day (1/4-20 tap) I opt for the best quality to maximize my productivity.

Also, just because you can "yank" on parts of the lathe (cross-feed slide) and not "detect" any "slop" does not mean the machine tool is "tight"... The forces present when actually making chips far exceed what a human can produce by tugging on parts of the machine. You only know how tight it is when you start to cut the steel...

Just because the motor spins does not mean the lathe is ready to plunge an expensive carbide form tool into an old locomotive tire....

Note: even the APEX folks are reluctant to sell "carbide tipped" form tools; (from the above linked APEX website)

CARBIDE TIPPED TOOLS
We furnish tipped tools, but do not guarantee the performance of cast alloys, or carbides.


And, If I'm wrong and the lathe is in "tippy-top" shape and ready for a carbide form tool then you will have $100 worth of tool bits in your tool box for all the other tasks that will come up. They won't go to waste.

Also, if you plan on a lot of work with your wheel lathe you might want to consider a grinder something like this;

https://www.acmetools.com/shop/tools/ba ... rinder-532

You can find these at a lower price point "hobbyist quality" that come with a "green wheel" which will sharpen HSS and carbide tools, and you can upgrade them to a diamond wheel. Probably a "must have" if you are going to do a lot of wheel lathe work. Grinding lathe tool bits is a bit of a "lost art", I had an uncle that thought me the basics. It was an everyday task back in the "old days".

Good luck, let me know if I can help.

Also the Strasburg folks have a lot of experience running a wheel lathe in the modern era, they may have better/different advice than mine.

Cheers, Kevin.


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Fri Jan 01, 2021 1:30 am 

Joined: Fri Mar 14, 2014 11:44 pm
Posts: 92
NYCRRson wrote:
I would recommend against a carbide form tool, probably cost several thousand dollars and likely to get decimated during your first try at machining an old tire.

I agree. We had our form tool made from HSS with a TiN coating.

Quote:
Also, form tools of any kind require a lot of horsepower (probably 10-15 hp) and complete rigidity of the machine tool, any backlash in a cross-feed screw, slop in the headstock bearings, or a lose gib and you will get chatter out the wazoo and a terrible surface finish.

Our Niles lathe has a 40HP headstock motor. The one at OERM I think is larger. Good point about the rigidity. I'm not sure how the headstock bearings are put together on these machines. You don't have conventional V&flat ways. There are two toolposts, one for each wheel. The tools are pretty big, on the order of 2x2 inches. I'll have to go take a photo and post it for you to see what I mean.


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Fri Jan 01, 2021 5:30 am 

Joined: Tue Sep 13, 2005 9:54 pm
Posts: 80
I have operated a couple of driver wheel lathes which used the original style tooling, which consisted of a High Speed Steel tools usually Cobalt HS. Wheel lathes were designed for RPM to cut at about 20 surface feet per minute. When turning locomotive driving wheels measure all flange thickness with a steel finger wheel gauge and tape diameters then calculate which wheel will turn up the smallest size and machine it first. Some time if one wheel has a thin flange and the other wheel don't it will save service metal to change out the one tire remember a 15/16" thick flange takes about a 1/2" of tire thickness to restore.
Using the round nose or round roughing tool to turn the thread and top the flange. Then rough out the flange with the flange form roughing tool. The the flange and most of the thread is machined to finish with a full form [flange and thread] plunge tool . This takes a lot of rigidity and slow RPM to prevent chatter. One of the reason wheel lathes were so heavy built and placed on very heavy concrete foundations. After finishing most of the thread and flange the last form tool completed the rest of the thread and the chamfer or radius on the outer edge of the thread

Is your wheel lathe is still equipped with the tool holders for the form tools or if you have the original tools for samples various cutter shops could make the tools also Apex Tool and cutter make them but they will be very expensive.

For the roughing tools I have purchased 32MM round carbide insert tools and holders.

Some wheel lathe were equipped with turret tool post which held all four tools so no extra holders would be needed

If your lathe has no holders of cutting tools I would suggest changing the machine to lathe Hydraulic tracer attachments which can be purchased on EBay for under $1500 then simple carbide insert tooling will work. Usually the Faceplate RPM would need to be increase and longitudinal slide feed decreased . I know the Strasburg RR did this on there wheel lathe and others turn wheels on engine lathes this way. In my option this is the way to go as makes machining easier. Converting to tracers would also probably require engineering to obtain tool heights and thread form template holders.

What is the make, age and size of you wheel lathe?

Please contact me if I can be of any help


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Mon Jan 11, 2021 10:42 am 

Joined: Mon Jan 11, 2021 10:22 am
Posts: 4
Hi Mel - I would recommend contacting Simmons Machine Tool Corporation in Albany, NY, as we are the OEM for that lathe, having acquired the product line in the 80s. There's a solid chance that we have some or all of the documentation for the machine - I know my colleague Dennis Rymanowski has supported similar restoration projects with success.

Here's the URL: https://smtgroup.com - if you have the machine's serial number handy, that would be of immense help.

Good luck finishing this restoration project! I'd love to see photos of such things when the machine is reprofiling wheels.

For the sake of transparency: I'm the marketing guy at Simmons.


Offline
 Profile  
 
 Post subject: Re: wheel lathe cutting tools
PostPosted: Fri Jan 22, 2021 3:49 am 

Joined: Tue Aug 24, 2004 6:30 am
Posts: 708
By any chance would you know the history of the lathe? What shop did it come from?


Offline
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 12 posts ] 

All times are UTC - 5 hours [ DST ]


 Who is online

Users browsing this forum: No registered users and 15 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: