pval3
11-28-2007, 02:52 PM
OK - Ive come to the mountain for answers after a very informative search of all forums for this dynamic bird here and in RCU and EZ....with no clear answers - - oh gurus provide me wisdom!
Here is my question:
Hobby lobby mixes this plane ( http://www.hobby-lobby.com/vdiamond.htm ) with a very light weight AXI 2212/20 OUTRUNNER turning an 8 X 8 apc prop and an 18 amp jeti speed controller.
Of all accounts, the motor combination works fine but speed is not where is needs to be and everyone building this plane notes that they have to add a boat load of lead to the nose to get it to balance out (battery box is very limited so adding more "useful load" in not possible.
There is also limited space in the motor mount area for deeper motors - that is rally no big issue, just lenghten the mount - however, doing that would also push the cg further back thus increasing the mount of lead to the nose!
The standard "small electric screamers" sound great but they are designed to push small light airplanes around with small props, this has more of a pylon racer/ ducted fan lineage small thin wing with high wingloading . .
Wingspan: 36” Wing Area: 193.8sq” 12.5dm2 Wing type: Built up sheeted balsa AUW weight: Advertised – 27oz Actual - 28.2oz Length: 33” Wing loading: 21 oz/sq. ft. most folks posting say it comes out to 30/31 oz range than the mfg advertized 27.5 oz. thus increasing the loading.
I guess the trick is that the motor has to be more of a "big plane" motor and prop it down than a park type motor like many are trying and failing to get the necessary push. The booms limit the prop to a max of 9.5" and that is providing very limited clearance with the booms.
I could use some assist with motor choice.
The axi 2212/20 is very impressive especially at 2 oz weight ( http://www.hobby-lobby.com/brushless-axi2212.htm ) , but looking for something a with a little more, ... Here is what I have found so far.
what do you all think of these (keeping weight/cg issues in mind with tailheavy situation)
http://modelaero.com/Merchant5/merc...Category_Code=M (http://modelaero.com/Merchant5/merchant.mvc?Screen=PROD&Store_Code=M&Product_Code=SM2212&Category_Code=M)
http://www.rc-dymond.com/index.php?productID=1196
http://www.hobbycity.com/hobbycity/...?idProduct=5688 (http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5688)
http://www.hobbycity.com/hobbycity/...?idProduct=6263 (http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6263)
http://www.graysonhobby.com/catalog...products_id=569 (http://www.graysonhobby.com/catalog/product_info.php?cPath=74&products_id=569)
Thanks o wize ones!????
Here is my question:
Hobby lobby mixes this plane ( http://www.hobby-lobby.com/vdiamond.htm ) with a very light weight AXI 2212/20 OUTRUNNER turning an 8 X 8 apc prop and an 18 amp jeti speed controller.
Of all accounts, the motor combination works fine but speed is not where is needs to be and everyone building this plane notes that they have to add a boat load of lead to the nose to get it to balance out (battery box is very limited so adding more "useful load" in not possible.
There is also limited space in the motor mount area for deeper motors - that is rally no big issue, just lenghten the mount - however, doing that would also push the cg further back thus increasing the mount of lead to the nose!
The standard "small electric screamers" sound great but they are designed to push small light airplanes around with small props, this has more of a pylon racer/ ducted fan lineage small thin wing with high wingloading . .
Wingspan: 36” Wing Area: 193.8sq” 12.5dm2 Wing type: Built up sheeted balsa AUW weight: Advertised – 27oz Actual - 28.2oz Length: 33” Wing loading: 21 oz/sq. ft. most folks posting say it comes out to 30/31 oz range than the mfg advertized 27.5 oz. thus increasing the loading.
I guess the trick is that the motor has to be more of a "big plane" motor and prop it down than a park type motor like many are trying and failing to get the necessary push. The booms limit the prop to a max of 9.5" and that is providing very limited clearance with the booms.
I could use some assist with motor choice.
The axi 2212/20 is very impressive especially at 2 oz weight ( http://www.hobby-lobby.com/brushless-axi2212.htm ) , but looking for something a with a little more, ... Here is what I have found so far.
what do you all think of these (keeping weight/cg issues in mind with tailheavy situation)
http://modelaero.com/Merchant5/merc...Category_Code=M (http://modelaero.com/Merchant5/merchant.mvc?Screen=PROD&Store_Code=M&Product_Code=SM2212&Category_Code=M)
http://www.rc-dymond.com/index.php?productID=1196
http://www.hobbycity.com/hobbycity/...?idProduct=5688 (http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5688)
http://www.hobbycity.com/hobbycity/...?idProduct=6263 (http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6263)
http://www.graysonhobby.com/catalog...products_id=569 (http://www.graysonhobby.com/catalog/product_info.php?cPath=74&products_id=569)
Thanks o wize ones!????