10-02-2013, 10:39 PM
A question that I have always had in my mind re lathes is how to machine the spokes of Flywheels (For Model Steam Engines) or the spokes on Model steam Locomotives.
Any Easy Answers?
Any Easy Answers?
Machining Spoked wheels
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10-02-2013, 10:39 PM
A question that I have always had in my mind re lathes is how to machine the spokes of Flywheels (For Model Steam Engines) or the spokes on Model steam Locomotives.
Any Easy Answers?
11-02-2013, 09:03 AM
Hi,
This sounds interesting. Do you have a picture and more details please as to what you wish to achieve. What material do you intend to use also what sizes? Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
12-02-2013, 05:42 PM
Hi Col,
At the moment I don't need a flywheel etc., but I would like to know how to machine one from a solid block with only a lathe. The same goes for finishing the castings for model locomotive wheels. I attach some photos of finished flywheels and Loco wheels plus some wheel castings. The diameters could be between 2.5 and 6 inches. BRs Mike
12-02-2013, 08:26 PM
Hi,
Thanks for adding the pictures Mike. I think a lot of roughing out can be done on the lathe regarding making these wheels; obviously the simpler design will be easiest to start with as access is much better to each spoke but with a bit of imagination once a simple wheel has been completed you could expand on how you achieved it. If it was me and I had a cast iron blank rather than a wheel casting for simplicity I would turn the blank to finished sizes regarding diameters and thicknesses adding the bore. Now I would have to turn a suitably profiled cutter to round over the spokes one that would cut both on the end and face; such cutters could be made of silver steel quite cheaply; hardened and tempered similar to a router bit and I've done a quick drawing to explain better. I've added a quadrant curve but any curve to suit the job could easily be formed; such a cutter would not cut into sharp corners but such corners could be finished by filing if needed. Then I would arrange a vertical mounting on the cross slide something like a vertical slide on which to mount the newly turned blank then with the new cutter in the chuck adjust the height of the spoke which would be accurately arranged horizontally; put the lathe in motion and use the cross slide to round over each spoke. This would be a starting point for me and at least an idea rather than a blank sheet of paper. Such jobs are time consuming in the extreme but most interesting. Something to think about? Kind regards, Col. Spoke rounding cutter.
Happiness is a wreck of a cabinet to restore.
12-02-2013, 08:54 PM
http://www.ebay.co.uk/itm/Radius-4-5mm-2...ltDomain_3&hash=item43b69e6a39
Machining those thin spokes in CI would be fun, I don't think. Alan
13-02-2013, 09:31 AM
Hadn't thought of spinning the cutter, I guess it could also be a 180 degree form to do back and front at the same time. Only problem are the ends and roots of the spokes, because of the inside curve at the end they can't really be filed except at 90 degrees.
How about the Loco wheels which get so fine at the centre? I had some wheel castings for a gauge 1 loco many years ago and they were pretty rough. BRs mike
Hi,
What you are trying to achieve Mike certainly won't be easy especially on the small diameter wheels. Yes getting right into tight corners is difficult but then problems usually have answers if determined enough to find them. With the larger wheels and flywheels rather than go to lots of trouble and many hours of machining using the lathe I would consider making a copy of the item I needed in wood and giving it a really good finish; then I would take it along to a foundry and let them copy it in whatever metal was suitable; the fine finish would be imparted to the newly cast item saving hours of fettling and frustration. The wooden item could then be stored on hand should other copies be needed? The smaller wheels do indeed pose a problem in getting into their sharp corners but again there will be a way to resolve the problem. One thing I can think of is to use a scroll saw with a piercing blade to remove excess metal; these blades are available in very fine section; they are used extensively for marquetry and I've used them successfully for cutting out brass nameplate letters. If the castings are rough how about simply sand blasting them? Depending on the cast iron some iron is easier to work than others; I've worked with cast iron that had an outer skin which was incredibly hard and could destroy cutting tool edges very quickly indeed; to machine this hard skinned cast iron the tool needs to be cutting deeper than the outer skin. I've produced gear wheels cutting them on the lathe very successfully using continuously cast Meeanite blanks; http://www.meehanitemetal.com/htmlpages/whats_diff.html The wheels in picture six look impossible to machine at home from a blank but I think I could make a fair attempt at making them should I have the time and inclination to have a go. I was thinking about these in bed during last night because I'm sad. I can't think of any way to produce such wheels from a solid blank but my thoughts turned to bicycle wheels and how these are assembled using only four components; the hub; spokes; nipples and rim. By breaking such a wheel down to its basic parts a simple mini production line could be set up in the home workshop. The hubs and rims could be turned in bulk using the lathe; the spokes could also be produced on the lathe; round rod of suitable diameter for the spokes could be accurately cut to length and threaded at each end ensuring the threads would be buried by the hub and rim. Nipples could be produced from hexagonal stock; cut over length turned at one end to a shouldered diameter and internally threaded on axis. Simple drilling jigs could be made to align drill bits and used in conjunction with a printed paper indexing template the tapping and clearance holes could be drilled one at a time. Assembly would be straightforward; the spokes would be fully screwed into the hub then each nipple added through the rim and whilst adjusting to run true again on a simple jig the nipples could be securely tightened using a small socket on the exposed hexagon end. Now the completed wheel could be chucked and the surplus nipple ends turned down flush to the outer edge of the rim. The wheels could be made from steel or brass; cast iron would be unsuitable for thin section spokes and would break too easily. This all sounds like over the top but then what you intend to or would like to do is impossible in the home workshop Mike? A while ago I cut 45 cast iron involute gears using my lathe using a technique I believe unique to me; it took a lot of time and effort and the lathe motor expired in a cloud of smoke but I succeeded. Even if you don't have a go Mike its still an interesting topic to discuss. I'm sure if I got into the garage with the intention of producing these wheels ideas would pop into my head. I'll be pleased if anyone else suggests another method because after all there is usually more than one way to do a job. I'll be glad when it stops snowing and the temperature is a plus rather than a minus then I can get cracking with a few projects. Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
13-02-2013, 05:06 PM
Hi Col,
I don't really envisage doing any of this, It was a question on how it would be done. Looking at Station road steam for example, there are many projects at various stages and I wondered how wheels etc were done. I bought a little lathe a couple of years ago from Bauhaus in a sale, it was 25% of the present price. I didn't have a bench or anywhere to put so it stayed on top of a cupboard. Last week I made a bench out of some 8cm thick wood and maybe next week I'll strip it and follow the setting up instructions that are on the web for this series of lathes. I've got some bits of an unfinished stationary steam engine so I may start there or else with some Anode connectors for 813s and 833s. Thanks for the advice and info, when I decide to make the flywheel for the above I think I'll make the centre solid with large circular holes, ie no spokes as such. BRs Mike
13-02-2013, 11:02 PM
I have had a look at the spoked wheels on a Mammod that has been on display for many years before it had to be rescued during an emergency house move.
The wheels look like they have been cast in a 2 part mold. The seams where the two parts meet can be seen on all three examples. The largest wheel looks like it was made in a mold with "fingers" that met with the spokes. The rims and axle holes would have been dressed on a lathe. In order to reproduce one from solid material would be difficult with only a lathe. A milling machine would make the task relatively easy compared with doing it on a lathe alone.
14-02-2013, 09:45 AM
Hi,
The number of lathe owners is steadily growing on this forum Mike; good luck with yours but please be careful; lathes are addictive and I'm beyond hope owning five. Its strange Mike that someone can have an idea pop into their head and it lays dormant for many years only to pop up once again and be acted upon; who knows; it's possible once you get settled with your lathe you might be tempted to tackle these wheels? Many of these wheels will have indeed been cast in a two part mould as you say Refugee as this is a very simple and economical method. This is why I mentioned making a pattern out of wood and finishing the pattern to a very high standard; once cast the new item would retain the same high degree of finish. The reason I know is because I've done it. Many years ago I made a wooden pattern of a lathe head-stock this for a wood-turning lathe I intended to have a go at making; I had two of these cast and they are very heavy in cast iron. I designed the pattern to be slightly tapered from front and back which would allow easy release. The pattern was taken along to a local foundry (Roberts Castings) and I parted with a very reasonable £80 for the pair. Due to life in general I never did get around to finishing the lathe although I'm sure I still have the castings under the bungalow. Where I worked we had our own casting department but this was aluminium only brass and cast iron were contracted out but as I worked in Despatch many moulds came through going to the foundry. Cope and Drag are the names for the parts of the two part moulding box and a bit of detail can be viewed here; http://en.wikipedia.org/wiki/Cope_and_drag The guy I bought my Jubilee lathe from has his own back yard foundry and casts items from brass which is useful to know. The 5ltr of pure alcohol has just arrived I bought through eBay on Tuesday so I can now mix up some shellac; today is going to be a good day. Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
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