[anadler]

Would like comments and opinions on forged verses CNC machined risers. Quality control, precision, finish, price, etc,

 

[Rylando]

Someone can correct me if I'm wrong, but typically forged risers cannot go much above 30lbs draw weight, while a CNC machined riser can go much higher. I've seen a handful of forged risers that have snapped in half when shot at 35-40lbs.

Much nicer overall finish on CNC risers versus forged typically, but whether that's solely due to their production or that CNC risers typically go for more $$, and thus you expect a nicer finish I'm not sure.

This is all from someone who just shoots them, I don't design them.

 

[Vittorio]

Basically a forged riser is stronger than a fully machined one in the same alloy and with the same sections, as metal fibers are compressed.
But making a forged riser perfectly straight means a complicated process with 3 forging and tempering phases normally few can afford to make. So making a forged high-level risers means to spend too much in toolings for a small volume sales, and forging has therefore been abandoned for high-end risers.
In medium-low end, forging had advantages of reduced material cost, in exchange of a bit more relaxed tolerances. But in these days, forging is definitely a rarity, as milling cost has been reduced a lot.
By the way, all those low end risers you have seen broken were surely casted, not forged. Not so many forged risers ever existed and are still existing, and none of them ever had a 30# limit (that is the limit for cheap casted risers and for those milled in low strength alloys )

 

[tylerjkrahn]

Some of those cast risers are magnesium, which I would not want to be shooting with high poundage limbs.

 

[LouGubrious]

Cast: not even once. Any brand producing a cast riser should be ashamed of themselves. Casting can produce strong, quality components, but at a prohibitive cost.

Milled/CNC: quality depends on the quality of the billet as well as the tolerances and maintenance of the mill. Well made milled risers like Vittorio mentioned start with a forged block. When a blank of metal is forged, the crystals in the metal align. In this case, they are going to align into a very strong blank. All the grain is going the same way, which is good, but it could be better. Some cheap risers are milled from alloy that has not been forged and thus has a chaotic grain structure that will be more likely to fatigue and fail.

Forged: getting a billet close to the final shape via forging has the advantage of aligning the metallic crystals not just together in the shape of a block, but together in the shape of the riser. All forged risers must be CNC finished. This inherently means a forged riser undergoes both forging and milling. The problem is that if you try to create a riser from a block of alloy with one forging step and one milling step, you will not have good results. This is the danger of cheap forged risers which are often made to very loose tolerances.

Carbon Fiber: can have what ever positive attributes you could want, so long as 1) the carbon pre-preg is appropriate 2) and was kept at the right temperature and humidity 3) and was laid into a clean, to-spec mold 4) by someone who understands and cares about the very fiddly work they are doing 5) to the exact specifications of the engineering team 6) who did enough high quality modeling and enough prototyping to actually create what they intended. There are probably 300 steps I'm skipping in the middle. Maybe some day CF will do for risers what it has done for bicycles and racecars, but I'm not holding my breath.

 

[tylerjkrahn]

I think the cf risers will take off for newer shooters but hard to make a change for guys shooting aluminum for so many years already

 

[SDguy]

If Carbon fiber works in the aircraft, space craft & satellite industry, Oh golf club shafts Wind tower blades and arrows are fairly high users as well.
I expect there will be a strong future w archery risers. I have had great experience thus far w carbon fiber risers for nearly 3 years now & I am sure others have been pleased for much longer. For what ever reason the carbon risers have not gained a hold in the target archery riser market as of yet. Expect this is bound to change.

 

[LouGubrious]

SD, in all of those cases a huge amount of money is on the line and the expense of engineering and producing specific parts from CF is swallowed in the overall price of the item. Specific to aerospace, in many cases the final product can't exist without components with the capabilities of CF (or titanium, magnesium, various grades of stainless steel, etc). CF does not, at present, provide a meaningful upgrade over well-made alloy risers. There are tangible and to some desirable differences shooting CF vs alloy, but none of those differences are plane stays in the air vs plane falls to the ground differences.

Ultimately, CF is almost always chosen when adding lightness is worth the price. I shoot barebow and I don't frankly want a light weight riser. Maybe if I was into hunting, the weight thing would be a bigger deal, but that's not my case. Until a company can make something really compelling (say a custom weighted, balanced, and tuned riser laid up to a specific shooter's needs) I just don't see that market taking off.

 

[Vittorio]

Carbon Risers is a general definition like Aluminium Risers. Then you have to go to specific features and way of construction, and only one maker in the market is really exploring the possibilities of Carbon in terms of lightness: Fiberbow. They make risers using a technology derivated from carbon Bicycle frames ending up getting the lightest risers in the market, 650g for the 6.9 and around 900 g for the coming risers based on GT technology. All other so so-called Carbon risers are just made by composite materials of many different kinds including carbon fibres end ending up to be as heavy or heavier than corresponding Aluminium version. This, added to the additional cost, easily explains why they have not been so successful.

 

[caveman1440]

Vittorio, maybe you can help me out on this. I used to shoot a Yamaha SuperFeel Forged back in the day, and my understanding is those were carbon fiber risers that were forged first and then milled/machined out to pattern, is that right?

I definitely liked that bow and won a couple nationals with it, but there is such a thing as too light. Like Lou said, for us target shooters light weight is not a big deal and I found the Yamaha did not feel as good at release as some heavier bows. Then, of course, there's the price, and I don't think Yamaha ever sold enough of them to be profitable considering the cost of production and they exited the archery business not much later.

Also, I did shoot 40+ pounds with that riser with no issues (their ceramic limbs were a different matter, but that's another story...)

-Luke

 

[UK_Stretch]

The Yamaha SF Forged was forged aluminium. They had a “special” forging process (and a fancy name for it I can’t remember). Many, many failures at QC but most that made it to market were OK. At least until the thermoplastic plate that held the limb in failed. The plate was not present in the SFF2. It was only available in 23” as well so that Explains why it was relatively light. I’m sure if you googlate it you can find an old add with all the marketing jumbo.

AFAIK the only carbon Yamaha was Centenial (Something like that) and it was a collectors item not really intended for use and was $$$$$$.

Stretch

 

[tylerjkrahn]

I wonder if Hoyt will jump into the carbon game for recurve, the hunting bows seem pretty popular

 

[caveman1440]

The Yamaha SF Forged was forged aluminium. They had a “special” forging process (and a fancy name for it I can’t remember). Many, many failures at QC but most that made it to market were OK. At least until the thermoplastic plate that held the limb in failed. The plate was not present in the SFF2. It was only available in 23” as well so that Explains why it was relatively light. I’m sure if you googlate it you can find an old add with all the marketing jumbo.

AFAIK the only carbon Yamaha was Centenial (Something like that) and it was a collectors item not really intended for use and was $$$$$$.

Stretch

I was wondering about that, since carbon fiber's not really a material that can be forged, right? Forging is a specific process involving heat and pressure, and carbon fiber is fabricated completely differently. Yet I feel like I remember people back then making a big deal of Yamaha's and carbon fiber, so I must be thinking of the Centennial you're talking about there, Stretch. And those plates, ugh....hahaha

 

[LouGubrious]

Caveman, all CF is technically forged. Most CF starts out as sheets of material impregnated with a resin coating. All the various sheets of carbon are layed up in a mold. That mold is then put in an autoclave where it is heated and pressurized with steam. The temperatures and forces are vastly less than in forging metal, but you don't get a completed CF component without heat and pressure.

 

[caveman1440]

Caveman, all CF is technically forged. Most CF starts out as sheets of material impregnated with a resin coating. All the various sheets of carbon are layed up in a mold. That mold is then put in an autoclave where it is heated and pressurized with steam. The temperatures and forces are vastly less than in forging metal, but you don't get a completed CF component without heat and pressure.

Just to be clear, Lou, are you saying that the process by which carbon fiber is made involves putting it in an autoclave and forging it using steam? Or are you saying that the process by which various components are made using carbon fiber sheets involves an autoclave, etc.?

Just asking because I didn't think that's how carbon fiber (i.e. the raw material) are made; I knew about the layers and coatings, but didn't think there was any sort of forging process involved. That being said, I didn't think about a forging process using steam for heat and pressure but what you describe makes sense for producing some type of end product, whether it's a riser or a high-performance car exhaust.

 

[anadler]

Thanks for all the comments, opinions and technical information on risers. Lancaster Archery has 70 ILF Olympic recurve risers listed. Priced from $99.99 to 999.99. Made from aluminum, carbon fiber and magnesium. Made by casting, forging, forging and machining and CNC machining. Made by numerous companies. I believe most amateur archers are looking for a riser at a reasonable price that they can reasonably believe it wont break, the limb pockets will be in line, the stabilizer bushing will be on center, no twist, etc. Confusing! Any comments?

 

[LouGubrious]

Cave, the first of the two. Actual carbon fiber is made on looms much the way any woven fabric would be. The woven material is impregnated with heat-activated resin. For bicycles, which is what I'm most familiar with, a three part mold is used: two pieces for the outside upon which the strips of CF are laid in a specific pattern, and then usually a third part that inflates inside the mold to compress the CF against the inside of the mold. Some cheaper bike frames don't use any internal mold or bladder and the result is weak spots over the length of a part.

 

[caveman1440]

Cave, the first of the two. Actual carbon fiber is made on looms much the way any woven fabric would be. The woven material is impregnated with heat-activated resin. For bicycles, which is what I'm most familiar with, a three part mold is used: two pieces for the outside upon which the strips of CF are laid in a specific pattern, and then usually a third part that inflates inside the mold to compress the CF against the inside of the mold. Some cheaper bike frames don't use any internal mold or bladder and the result is weak spots over the length of a part.

Fascinating stuff Lou, I've always wondered about carbon bike frames- my dad spent a bunch of money on one back in the day and it was amazingly light (dunno about $6k light though...). The looms you refer are more what I had in mind when thinking of carbon fiber manufacturing. I'm pretty sure when it comes to arrows companies like Easton try to use a single sheet of carbon fiber in their production runs, which they roll around either a mold or an aluminum core depending on the arrow. I don't know much about the manufacturing process, that's just what I've picked up from various sources and I absolutely could be wrong.

Anadler, choosing a riser is a very personal choice for a number of reasons: fit and feel, of course, but also reliability, precision, and price. Without knowing much of your background, I would say find some way to test out a number of different models to see what you like. If you're just getting started, it's probably hard to go wrong with any decent (mid-range, $200-$400) ILF riser but if you've been shooting for a while and are more advanced, then that's different obviously. Either way, best of luck!

 

[Itsjtome]

Thanks for all the comments, opinions and technical information on risers. Lancaster Archery has 70 ILF Olympic recurve risers listed. Priced from $99.99 to 999.99. Made from aluminum, carbon fiber and magnesium. Made by casting, forging, forging and machining and CNC machining. Made by numerous companies. I believe most amateur archers are looking for a riser at a reasonable price that they can reasonably believe it wont break, the limb pockets will be in line, the stabilizer bushing will be on center, no twist, etc. Confusing! Any comments?

so ur saying that archers want a good riser? who knew?

 

[Vittorio]

so ur saying that archers want a good riser? who knew?

I use quite often mobile phones to explain the problem of choosing one among others. But just came back from buying a new city car ... same