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.
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.
