I couldn't stand it
#11
RE: I couldn't stand it
... and was getting ready to charge him 100 for fixing it.
#12
RE: I couldn't stand it
Like I said in the previous post,the limbs,limb pockets and cams had some value but trying to charge ME full price for something I fixed is a little rediculous.
#13
Fork Horn
Join Date: Nov 2007
Location: Painesville, ohio
Posts: 486
RE: I couldn't stand it
ORIGINAL: Arthur P
It does make one wonder how many bow tuning problems might be due to bent or warped risers. That's the one real problem I have with machined aluminum risers and the big reason I always preferred forged risers.
It does make one wonder how many bow tuning problems might be due to bent or warped risers. That's the one real problem I have with machined aluminum risers and the big reason I always preferred forged risers.
#14
RE: I couldn't stand it
Forging is not casting,the material is not melted.
http://www.industrial101.com/services/forgings.aspx
Forging is a metal forming process in which metal undergoes deformation by subjecting it to impact or pressure. The metal being deformed may be heated to an elevated temperature or it may be cold forged. Components such as: crankshafts, camshafts, turbine shafts, automobile parts, train parts, airplane parts, wrenches, pliers, surgical instruments and connecting rods, etc. are usually forged. The process of forging gives the components high strength, uniform grain structure and since they are near the final shape of the finished component, they also require less machining.
There are various types of forging methods that are common in the industrial world such as: Smith forging, drop forging, machine forging, open die forgings, closed die forgings, and press forging. There are also many types of forging equipment that are used in the process such as: pneumatic and hydraulic hammers, drop hammers, board drop hammers, steam drop hammers, gravity drop hammers, and forging presses, etc.
The billet, which is the metal component that is to be forged, is placed on the table with half of the die. The other half of the die is fitted to a hammer and the hammer is repeatedly dropped on the billet with high pressure, thus deforming the metal until it adopts the deformed shape. You may also use a press to pound and squeeze the metal.
The metal can be heated, but not melted, during the process of forging. However, in cold forging there is no heat applied to the metal. In this method the metal is shaped and molded by pressure alone. Cold forging is generally used for carbon and steel alloys to manufacture smaller parts
The billet can be made of various types of material such as steel, copper, brass, titanium, and aluminum, etc. Though the production rates are relatively slow, this is a mass production technique and the process has been around since biblical times when blacksmiths forged swords and ploughshares on their primitive anvils. The skill of the person who is doing the forging or operating the equipment will have a great deal to do with the overall quality of the finished forgings.
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http://www.industrial101.com/services/forgings.aspx
Forging is a metal forming process in which metal undergoes deformation by subjecting it to impact or pressure. The metal being deformed may be heated to an elevated temperature or it may be cold forged. Components such as: crankshafts, camshafts, turbine shafts, automobile parts, train parts, airplane parts, wrenches, pliers, surgical instruments and connecting rods, etc. are usually forged. The process of forging gives the components high strength, uniform grain structure and since they are near the final shape of the finished component, they also require less machining.
There are various types of forging methods that are common in the industrial world such as: Smith forging, drop forging, machine forging, open die forgings, closed die forgings, and press forging. There are also many types of forging equipment that are used in the process such as: pneumatic and hydraulic hammers, drop hammers, board drop hammers, steam drop hammers, gravity drop hammers, and forging presses, etc.
The billet, which is the metal component that is to be forged, is placed on the table with half of the die. The other half of the die is fitted to a hammer and the hammer is repeatedly dropped on the billet with high pressure, thus deforming the metal until it adopts the deformed shape. You may also use a press to pound and squeeze the metal.
The metal can be heated, but not melted, during the process of forging. However, in cold forging there is no heat applied to the metal. In this method the metal is shaped and molded by pressure alone. Cold forging is generally used for carbon and steel alloys to manufacture smaller parts
The billet can be made of various types of material such as steel, copper, brass, titanium, and aluminum, etc. Though the production rates are relatively slow, this is a mass production technique and the process has been around since biblical times when blacksmiths forged swords and ploughshares on their primitive anvils. The skill of the person who is doing the forging or operating the equipment will have a great deal to do with the overall quality of the finished forgings.
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#15
Giant Nontypical
Join Date: Feb 2003
Posts: 9,175
RE: I couldn't stand it
machined aluminum should be significantly stronger as it is melted and extuded, making all the inconsistancies and air in the metal exit. cast metal is generally much less stable. a bend in cast is catastrophic, a bend in Machined is repairable.
Unless you are a machinist who cuts a lot of aluminum, you'd have no idea how many internal grain stesses are built up inside a billet of aluminum by the manufacturing process. You wouldn't believe how easy it is to bend billet stock aluminum. You wouldn't believe how much the part will contract and expand with differences in temperature. (Ever set your peep in hot weather, but the first cold snapthat comes along yourpeep doesn't line up with your eye? There's the termperature effect on a machinedaluminum riser.)Parts cut from billet are actually not all that strong,because the billet's internal grain structure is cut through as the part is being produced.
Forging, on the other hand, compresses the internal grain structure. Forging forces the internal grain to mirror the external shape of the part itself so it is far stronger than billet.Parts made by forging arefar more stable to temperature fluctuations than those machined from billet. But since the aluminum is forcibly condensed, it also makes the part heavier than an identical one machined from billet.
In my job as an aerospace machinist, I couldn't tell how many tons of aluminum billet I cut into aircraft/missle/satelite parts. Close tolerance parts had to be machined ina specific temperature controlled environment because billet is so sensitive to temperature changes.I also know when the engineersreally needed enhanced strength at lower cost for a particular part, they had them forged at a foundry.
Forging technology is remarkable. They can forge a part within very close tolerances where very little machining needs to be done on them. I'd bet now, 19 years since I last turned a crank on a milling machine, the technology is even more refined.
Really, I have always thought the machined riser mania was misguided and fueled by the ill informed. In some ways, particularly temperature stability,I even think the lowly cast riser is preferable to machined.
#17
RE: I couldn't stand it
My question after all this is how did this riser make it out of the plant? Isn't there some sort of final quality control check that each has to pass before getting to the next stage in the assembly process?
#18
RE: I couldn't stand it
ORIGINAL: Arthur P
I must not have been paying attention if you said that before. I thought you were talking about a machined aluminum riser! Cast magnesium... I think I'd be drawing up the seat of my drawers in a serious pucker when drawing it ifthat thingneeded a lot of straightening. Watch for cracks!
This is a cast magnesium riser
Dan
#19
RE: I couldn't stand it
ORIGINAL: Roskoe
My question after all this is how did this riser make it out of the plant? Isn't there some sort of final quality control check that each has to pass before getting to the next stage in the assembly process?
My question after all this is how did this riser make it out of the plant? Isn't there some sort of final quality control check that each has to pass before getting to the next stage in the assembly process?