Joined
·
1,302 Posts
Forged aluminum is a lot stronger than cast.
Milled riser over a cast riser?
2801
37
What are the benefits if there are any? What if the bows both spec out the exact same, except for the riser composition?
1 - 20 of 38 Posts
Joined
·
2,092 Posts
Milled risers are stiffer and sometimes cast risers can have defects.
Joined
·
521 Posts
Billet????
Joined
·
2,514 Posts
billit is forged/machined not cast which is pretty much just metal poured into a mold.
Typically anything machined will be better/stronger then anyting cast. Casting like i said is just molded which can have a lot of imperfections like air pockets or other impurities.
Machined/billet is cut out of one solid piece of metal.
Then they have both, casts which get machined... They pour the mold then cut it to what the desired spec is.
By the way im a machinist
Typically anything machined will be better/stronger then anyting cast. Casting like i said is just molded which can have a lot of imperfections like air pockets or other impurities.
Machined/billet is cut out of one solid piece of metal.
Then they have both, casts which get machined... They pour the mold then cut it to what the desired spec is.
By the way im a machinist
Joined
·
7,994 Posts
A machined aluminum riser is a lot more dead in your hand compared to a cast magnesium riser. Cast magnesium is a little lighter though.
Joined
·
7,994 Posts
I bent a cast riser in a bowpress one time. I don't know if I did something wrong or if there was a defect in the riser, but I've never bent a machined aluminum one.
Joined
·
526 Posts
So you spends your dollars and make your choices. How long you gonna keep the bow? Is it just a stepping stone for you - your first bow; or something your gonna shoot for years. How deep are your pockets. If that's all you can afford - so what. Better than not shooting.
Joined
·
7,994 Posts
I agree with this. Buy what you can and shoot!
Joined
·
100 Posts
Risers Machined out of Billet aluminum will most likely weigh less and more precise but they have more waste during machining than a cast riser which in turn drives up the cost, however modern casting technologies can achieve very accurate parts as well. Coming from a process engineer I can say that machined risers will cause the bow to cost more because the machining process takes longer and is more labor intensive. As far as defects in a cast riser not to say they dont happen but with the amount of quality control measures in place nowadays I wouldnt not buy a cast riser because you are worried about defects if you cant afford a bow with a machined riser get a cast! I would also say that its safe to say most machined risers are cast and then machined to spec so weather you believe it or not your "machined" riser probably started out as a casted blank. Shoot what you like and can afford!
Joined
·
2,514 Posts
That is not a true statement, like i stated above i am a machinst and have seen and been around the machining of some bow risers. Not to say that a few manufactures dont machine cast, but almost all the upper end bow manufactures fully machine there risers out of a solid piece of aluminum. As for waste, there is some but the cost of aluminum is so cheep plus they recycle the chips and make back a portion of that cost. The amount of material it takes to make one riser is probably about $20 worth of aluminum if that. It wont make the manufacturing process that much more expensive. As for time, aluminum is soft and machines very fast.
The price difference comes more from the "idea" of having a fully machine riser. I work with machines and castings everyday and casting can be just as labor intensive.
Im not saying he shouldnt buy a cast bow if thats what his budget allows, ive shot a few that shoot pretty good.
Joined
·
9,072 Posts
I saw A guy at A 3-D shoot in 1990, pull back A Hoyt compound, Riser broke in half at the grip.....According to the guy it was set at 90lbs. DW.....:darkbeer::darkbeer::darkbeer::shade:
Joined
·
2,514 Posts
I should have added.... Those sold pieces of aluminum are "forged" not casted, there is a big difference.
Not to mention casting requires casting dies which are now usually....... Machined! And expensive, not mention that a die would be specific to one type of riser so ever year when they come out with a new bow they have to get new dies. Plus when they are doing the R&D and testing they usually make multiple changes requiring new dies. In cnc machining i just make a couple quick changes in my program and bam its done.
Casting is usually only a lot cheeper when u are stamping out tons and tons of something that never really changes. In the bow world stuff changes all the time so its not really as cost effective as you might think.
Not to mention casting requires casting dies which are now usually....... Machined! And expensive, not mention that a die would be specific to one type of riser so ever year when they come out with a new bow they have to get new dies. Plus when they are doing the R&D and testing they usually make multiple changes requiring new dies. In cnc machining i just make a couple quick changes in my program and bam its done.
Casting is usually only a lot cheeper when u are stamping out tons and tons of something that never really changes. In the bow world stuff changes all the time so its not really as cost effective as you might think.
Joined
·
630 Posts
All kinds of misinformation in this thread... Where to start?
Billet? Look up the definition of billet sometime: you might be surprised to find out it just means a chunk of metal. Billet can be cast - thick aluminum is often cast (gasp!) rather than extruded, so your precious billet is now cast "garbage." Think about it.
Extruded and cast aluminum have a lot of internal stresses due to the way the material dissipates heat and how that factors into residual stresses retained within the material during and after it's formed (the first step after being formulated in the foundry). Once it goes from the pour to the forming process (either extrusion or casting), it still needs to undergo some post forming heat treatments before it has the strength and rigidity we need for a functional part. This is where the temper comes in, and where a gummy pot metal takes on that magical "aircraft grade" marketing nonsense (it does get transformed from gummy crap though).
So now we have a "billet" that if we were to just stick on a mill and whittle away at it, it'd probably spring in at least three directions from uneven residual internal stresses. Any real machinist would know this, as it's what happens if you take a surface cut off one side of a piece of bar stock - you end up with a crowned bar because the side you just removed was holding the tension in check on the other side. If we remove enough stock, the stresses eventually balance out, and with some program tweaking, we can hold a decent tolerance (look into home built or marginal quality AR lowers sometime, as that machining process shows a lot of these characteristics in action - you couldn't give me a "billet" AR lower: forged is the only way to go there).
What most machined aluminum risers are made from is actually an extrusion which closely resembles the final bow's profile. From this extrusion (which undergoes tempering as a "raw" material), the riser's design/features are cut out. This eliminates the vast majority of waste you'd have milling a riser out of a piece of bar stock, but also eliminates fighting with the residual stresses like you would if you did carve the riser out of that thick of block (so it doesn't twist into a pretzl on you as you machine it).
So then we go one step further and say we want forged = the same "billet" we started out with is probably rough formed to some degree (be it cast or extruded), but then rather than simply letting that material harden and then shape it, we smash it under a great deal of pressure while it's hot, but not quite melty. This compacts the material, so there's 15# of stuff in a 10# bag (so to speak), but it also changes the molecular structure of the elements in the alloy in a very favorable way. A forged part of the same volume will weigh more than one cast or machined from bar stock - while nothing else has changed. Now since the forging is so much stronger than the "billet" (I really hate the term billet, in case you haven't noticed), we don't need as much material, and as such the part can be lighter yet and occupy even less space. One of the best examples of this would be forged automotive wheels. They're stronger and lighter than their non-forged counterparts.
What all this means to your bow - it's really a matter of personal preference. I owned an old cast riser PSE (which was a heavy turd), and now own a machined Diamond, and a forged Quest (both 2010's). The alloys being cast these days are probably about equal to a machined extrusion. It's strength or weakness becomes a matter of what the bow is made of and how it was handled at the foundry.
Billet? Look up the definition of billet sometime: you might be surprised to find out it just means a chunk of metal. Billet can be cast - thick aluminum is often cast (gasp!) rather than extruded, so your precious billet is now cast "garbage." Think about it.
Extruded and cast aluminum have a lot of internal stresses due to the way the material dissipates heat and how that factors into residual stresses retained within the material during and after it's formed (the first step after being formulated in the foundry). Once it goes from the pour to the forming process (either extrusion or casting), it still needs to undergo some post forming heat treatments before it has the strength and rigidity we need for a functional part. This is where the temper comes in, and where a gummy pot metal takes on that magical "aircraft grade" marketing nonsense (it does get transformed from gummy crap though).
So now we have a "billet" that if we were to just stick on a mill and whittle away at it, it'd probably spring in at least three directions from uneven residual internal stresses. Any real machinist would know this, as it's what happens if you take a surface cut off one side of a piece of bar stock - you end up with a crowned bar because the side you just removed was holding the tension in check on the other side. If we remove enough stock, the stresses eventually balance out, and with some program tweaking, we can hold a decent tolerance (look into home built or marginal quality AR lowers sometime, as that machining process shows a lot of these characteristics in action - you couldn't give me a "billet" AR lower: forged is the only way to go there).
What most machined aluminum risers are made from is actually an extrusion which closely resembles the final bow's profile. From this extrusion (which undergoes tempering as a "raw" material), the riser's design/features are cut out. This eliminates the vast majority of waste you'd have milling a riser out of a piece of bar stock, but also eliminates fighting with the residual stresses like you would if you did carve the riser out of that thick of block (so it doesn't twist into a pretzl on you as you machine it).
So then we go one step further and say we want forged = the same "billet" we started out with is probably rough formed to some degree (be it cast or extruded), but then rather than simply letting that material harden and then shape it, we smash it under a great deal of pressure while it's hot, but not quite melty. This compacts the material, so there's 15# of stuff in a 10# bag (so to speak), but it also changes the molecular structure of the elements in the alloy in a very favorable way. A forged part of the same volume will weigh more than one cast or machined from bar stock - while nothing else has changed. Now since the forging is so much stronger than the "billet" (I really hate the term billet, in case you haven't noticed), we don't need as much material, and as such the part can be lighter yet and occupy even less space. One of the best examples of this would be forged automotive wheels. They're stronger and lighter than their non-forged counterparts.
What all this means to your bow - it's really a matter of personal preference. I owned an old cast riser PSE (which was a heavy turd), and now own a machined Diamond, and a forged Quest (both 2010's). The alloys being cast these days are probably about equal to a machined extrusion. It's strength or weakness becomes a matter of what the bow is made of and how it was handled at the foundry.
Joined
·
10,765 Posts
Yes a die cast part can have porosity {air bubbles} and they can be warped if the die was too cold or too hot and not have enough oil/water lube sprayed on it .billit is forged/machined not cast which is pretty much just metal poured into a mold.
Typically anything machined will be better/stronger then anyting cast. Casting like i said is just molded which can have a lot of imperfections like air pockets or other impurities.
Machined/billet is cut out of one solid piece of metal.
Then they have both, casts which get machined... They pour the mold then cut it to what the desired spec is.
By the way im a machinist
But a billet can be just poured into a mold and have high amounts of dross in them as well. If done right a die cast riser or anything such as all the transmissions and motor blocks in vehicles can and are stronger due to the fact that the metal is injected very quickly into the die just a fraction of a second after it is poured into the shot chamber with as much as 2000 to 4000 FTBLS of hydraulic pressure. They are compressed as molten aluminum and there by heavier and stronger per inch of material than just poured billeted material .Billet is simply cheaper to make since all they are is machined ..
I Know these processes I am a team leader at Chrysler DIE-CAST plant that pours and casts a couple million tons of aluminum into motor blocks and transmissions I have been ther for almost 20 years
Joined
·
630 Posts
I have serious reservations about claiming the process used to cast engine blocks is remotely similar to that used to cast bow risers. Sure, you have sprues, and gates, and all that fun stuff, but I'm pretty sure they're not using high pressure delivery.
Even the most chest-pounding-manliest 150# draw bow still only uses a minute fraction of the strength of even a poorly cast riser.
Even the most chest-pounding-manliest 150# draw bow still only uses a minute fraction of the strength of even a poorly cast riser.
1 - 20 of 38 Posts
