Original Posted By: "Clif Dawson"
Had a conversation with my steel tube supplier today. For the record, my supplier is Tube Service in Portland Or. They advised me that there is 4130 Chromoly Steel available US made. It is available through a company called Wesco (is somewhere in Southern Calif.) and from Plymouth (in Arizona). From past experience I know that Plymouth does aluminium tubing also. My supplier agreed to replace all the Chinese tubing with made in USA tubing for no change in price. A great company. For the record I and four other individuals are building full size DH-2's. Using the basic Pietenpol specs on the gear, Ken Perkins hubs, 21"wheels with 21x3.25 tires.Ernie MorenoPiet 2431 ________________________________________________________________________________
Pietenpol-List: steel
Pietenpol-List: Re: steel
Original Posted By: "DOMIT"
There are 3 factors that decide selection of the Fork-end of the main strut:1) tension load, easily understood and both J-3 fork end and a Turnbuckle style fork can handle the required load.2) compression load, often over looked but flying in turbulence often experienced, J-3 fork can handle this, Turnbuckle style can not.Remember that turnbuckles are designed for cable use, no compression loads there.3) overlooked even more often is thread strength, diameter & length.For a steel fork end to work as designed the diameter should be same a as the height of the nut insert (nut part to be of the same material)In other words a 5/16 Fork tread needs to have 5/16 nut height, if you tap in to the strut your tread dept needs to be at least 5/16.Note: nut/ strut threads of the same steel material, more length is always better, rolled threads are better than cut/ tapped threads.I use the J-3 style fork end with steel struts and the weld-in treaded purpose build nut insert.Now if you choose to use aluminum struts and tap your own treads be aware that aluminum has a lower tensile strength than steel.So compensate by tapping a deep/ long thread in to the best aluminum you can get.Your fork tread might not be long enough.You might need to consider a steel insert.Turnbuckles assemblies with brass center piece use the same principle, the tread depth is much longer ( 6-8 X ) than the diameter of the tread.I did not sleep in a Holiday-inn express last night, but am a mechanical engineer by professionHansNX15KV________________________________________________________________________________Subject: Pietenpol-List: Re: steel
There are 3 factors that decide selection of the Fork-end of the main strut:1) tension load, easily understood and both J-3 fork end and a Turnbuckle style fork can handle the required load.2) compression load, often over looked but flying in turbulence often experienced, J-3 fork can handle this, Turnbuckle style can not.Remember that turnbuckles are designed for cable use, no compression loads there.3) overlooked even more often is thread strength, diameter & length.For a steel fork end to work as designed the diameter should be same a as the height of the nut insert (nut part to be of the same material)In other words a 5/16 Fork tread needs to have 5/16 nut height, if you tap in to the strut your tread dept needs to be at least 5/16.Note: nut/ strut threads of the same steel material, more length is always better, rolled threads are better than cut/ tapped threads.I use the J-3 style fork end with steel struts and the weld-in treaded purpose build nut insert.Now if you choose to use aluminum struts and tap your own treads be aware that aluminum has a lower tensile strength than steel.So compensate by tapping a deep/ long thread in to the best aluminum you can get.Your fork tread might not be long enough.You might need to consider a steel insert.Turnbuckles assemblies with brass center piece use the same principle, the tread depth is much longer ( 6-8 X ) than the diameter of the tread.I did not sleep in a Holiday-inn express last night, but am a mechanical engineer by professionHansNX15KV________________________________________________________________________________Subject: Pietenpol-List: Re: steel
Re: Pietenpol-List: steel
Original Posted By: Rick Holland
Subject: Re: Pietenpol-List: steel
Subject: Re: Pietenpol-List: steel
Re: Pietenpol-List: steel
Original Posted By: Rick Holland
Actually, we are building 5 DH-2's. Our first choice at this point is a 2276VW with a 2.5x1 belt redrive from Valley Engineering. This combo allows the use of 96x63 prop. This combo when tested gave 620 lbs. of statc thrust. I know it is not the same in the air, but I think that it will provide enough thrust to move 1000 gross aircraft through the air. Wing area is 256 square feet. Empty weight that I am shooting for is 690 to 710 lbs. It will carry approximately 15 gallons of fuel with up to a 250 lbs. pilot. There are some pictures of the project on EAA 292 chapter website.Ernie MorenoNoon Patrol Builder GroupPiet 2431 ----- Original Message -----
Actually, we are building 5 DH-2's. Our first choice at this point is a 2276VW with a 2.5x1 belt redrive from Valley Engineering. This combo allows the use of 96x63 prop. This combo when tested gave 620 lbs. of statc thrust. I know it is not the same in the air, but I think that it will provide enough thrust to move 1000 gross aircraft through the air. Wing area is 256 square feet. Empty weight that I am shooting for is 690 to 710 lbs. It will carry approximately 15 gallons of fuel with up to a 250 lbs. pilot. There are some pictures of the project on EAA 292 chapter website.Ernie MorenoNoon Patrol Builder GroupPiet 2431 ----- Original Message -----
Pietenpol-List: steel
Original Posted By: Steven Dortch
Subject: Pietenpol-List: steel
Subject: Pietenpol-List: steel