Bowturbo revisited.. a message from Len
12-03-2008, 04:38 PM
#1
Dominant Buck
Thread Starter
Join Date: Feb 2003
Location: Blossvale, New York
Posts: 21,199
Bowturbo revisited.. a message from Len
Our friend Len has fallen to the same pit that many have lately, can't seem to log on to this site for some reason. Ya'll know Len stays up on this stuff. He posted this on AT and thought it should e posted here too as it's a safety/warranty concern. So here's what the head tinkerer has to say about Bowturbo/snakeoil in his opinion. I'll try to get him through the loggin if I can find where in the hell I had to go to do it. Huntingal, where was that?[&:]
"You don't hear from me that often, but this is a major safety issue that I felt should be addressed. Keep in mind that there was a lawsuit about 8 years ago about someone loosing an eye due to a cable guard letting loose.
Warranty issues with the bow manufacturers would definitely arise concerning this product. Just as with the case of roller guards, the limbs will be stressed more by adding this device. The manufacturers have to compensate the design of the limbs for roller guards and that design compensation is not projected using this product.
Any damage to the limbs might not occur immediately, but I wouldn't want to buy a used bow from someone who correctly or possibly incorrectly used this product. Keep in mind that they just attached it with little regard to calculated stress factors. Can you imagine someone really pushing that thing a couple inches towards the riser to increase speed even more? Talk about preload. Questions that didn't seem to be actively addressed or checked were draw weight after installation. How much preload can be used? Actual effect on draw length?
Now that I've discussed the potential damage to the bow, let me address personal injury. At full draw you'll have rear ward pressure on a carbon rod that is held in place by a couple of set screws or glue. This rod was never meant to take excessive pull force. Then you'll have to place a piece of metal to usually a carbon rod that is not meant to take this kind of pressure generated by the set screws. This can easily create cracks in the carbon slide causing even more problems.
Depending on how far this device mounted forward, and depending on the bow design, varying forces will be amplified over what is normal. When the bow is drawn the force trying to drive the slide rod backwards would be like an arrow headed straight for the shooters eye with most of today's bow designs.
These are questions/issues that, for the most part, I can check with instrumentation/tools that I have designed and have readily available.
I had the parts available at the shop to make and duplicate this product.
I did some analyses on two different bow designs. Without getting into all the detail, which I'll make available to customers coming into the shop, this design is dangerous to both the bow and the shooter.
As others have suggested, DL and DW did increase depending on bow design. My testing was done using a bow set only at 60# and I'm glad I used some discretion. With it on my draw machine and moving the device from zero/static to 1/2" closer to the riser to increase speed, the unit let loose, probably due to the camo finish becoming somewhat of a lubricant, and became a backward projectile. Had I been drawing the bow by hand, I would have been hit in the face.
Yes, your arrow speed will increase due to both DL and DW increasing, but the possible consequences of adding this product to your bow are NOT worth it.
IMPO, keep your money in your pocket."
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"You don't hear from me that often, but this is a major safety issue that I felt should be addressed. Keep in mind that there was a lawsuit about 8 years ago about someone loosing an eye due to a cable guard letting loose.
Warranty issues with the bow manufacturers would definitely arise concerning this product. Just as with the case of roller guards, the limbs will be stressed more by adding this device. The manufacturers have to compensate the design of the limbs for roller guards and that design compensation is not projected using this product.
Any damage to the limbs might not occur immediately, but I wouldn't want to buy a used bow from someone who correctly or possibly incorrectly used this product. Keep in mind that they just attached it with little regard to calculated stress factors. Can you imagine someone really pushing that thing a couple inches towards the riser to increase speed even more? Talk about preload. Questions that didn't seem to be actively addressed or checked were draw weight after installation. How much preload can be used? Actual effect on draw length?
Now that I've discussed the potential damage to the bow, let me address personal injury. At full draw you'll have rear ward pressure on a carbon rod that is held in place by a couple of set screws or glue. This rod was never meant to take excessive pull force. Then you'll have to place a piece of metal to usually a carbon rod that is not meant to take this kind of pressure generated by the set screws. This can easily create cracks in the carbon slide causing even more problems.
Depending on how far this device mounted forward, and depending on the bow design, varying forces will be amplified over what is normal. When the bow is drawn the force trying to drive the slide rod backwards would be like an arrow headed straight for the shooters eye with most of today's bow designs.
These are questions/issues that, for the most part, I can check with instrumentation/tools that I have designed and have readily available.
I had the parts available at the shop to make and duplicate this product.
I did some analyses on two different bow designs. Without getting into all the detail, which I'll make available to customers coming into the shop, this design is dangerous to both the bow and the shooter.
As others have suggested, DL and DW did increase depending on bow design. My testing was done using a bow set only at 60# and I'm glad I used some discretion. With it on my draw machine and moving the device from zero/static to 1/2" closer to the riser to increase speed, the unit let loose, probably due to the camo finish becoming somewhat of a lubricant, and became a backward projectile. Had I been drawing the bow by hand, I would have been hit in the face.
Yes, your arrow speed will increase due to both DL and DW increasing, but the possible consequences of adding this product to your bow are NOT worth it.
IMPO, keep your money in your pocket."
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12-03-2008, 05:02 PM
#2
Giant Nontypical
Join Date: Feb 2003
Location: HENDERSON KY USA
Posts: 6,634
RE: Bowturbo revisited.. a message from Len
Funny,I was going to do the same and saw this thread so I went out and did a quick test.
The poundage increased 3#'s(I think the actuall product would be slightly less) and the draw length a 1/4".There is the majority of the speed gains.BUT,I also checked timing and it was way off as well and my Whammy got stuck about half way down.
So, a major retuning would be needed as I suspected.
The poundage increased 3#'s(I think the actuall product would be slightly less) and the draw length a 1/4".There is the majority of the speed gains.BUT,I also checked timing and it was way off as well and my Whammy got stuck about half way down.
So, a major retuning would be needed as I suspected.
12-03-2008, 05:21 PM
#3
Nontypical Buck
Join Date: Nov 2003
Location: West Chester, Pa.
Posts: 1,892
RE: Bowturbo revisited.. a message from Len
Len is a guy I always listen to when he has something to say about a new product....definately won't find its way onto my bow. Speed is overrated anyway
Shane
Shane
12-03-2008, 05:25 PM
#4
Nontypical Buck
Join Date: Feb 2003
Location: Heaven IA USA
Posts: 2,597
RE: Bowturbo revisited.. a message from Len
As I recall a number of years ago Saunders had some type of device that they may have even called a "turbo" that yielded similar results. Needless to say it went no where.
Bottom line...there is no free lunch.
Any increase in speed/power has to come from somewhere.
Bottom line...there is no free lunch.
Any increase in speed/power has to come from somewhere.
