Bolt replacement on Benson Hub Bar

[Greg Mitchell]

G'Day Gents,Have all the necessary bolts to replace pitch block bolts, pillar block bolts and blade retention bolts.The Pillar Block on Hub Bar is slightly skewed, in other words it's not exactly flush with the edge of the hub bar, there seems to have been some twist over the years. These Benson Blades and Hub Bar were manufactured back in 76'.Questions I have are:-1. Any special technique for marking current position of pitch blocks as I replace bolts, for instance, If I remove one old bolt and install a new one, before doing the next, will this maintain the pitch setting????2. Do I try and set the Pillar Block (hub) flush with edge of Hub Bar??3. Did the benson hub get glued as well?Any advice welcome.[]Cheers.Mitchwww.thebutterflyllc.com

[Tim]

G'day Mitch. Just bolt your blades together as you would do normally and then remove and replace the bolts one at a time, retensioning each new bolt as you go. Some blade manufactures fill the holes around the vertical pitch block bolts with loctite and they cannot be replaced. The pillar block bolts are just replaced and the holes are usually neat so the block will probably still end up slightly skewed.Regards TimTim McClure

[Greg Mitchell]

Thanks Tim, that all makes good sense.Regards,Mitch.www.thebutterflyllc.com

[asra]

Howdy MitchYou may have damage to the teeter block or,hur bar and other componets.You realy should do a complete inspection.I would place two pieces of masking tap at each part juncture about a 14" apart and mark the gap with prussion blue (a dye for marking)it's used in machine shop's.It cleans of easyly so be carefull while handleing the parts.Also if you try to put a part in the wrong place the marks wont line up so placement of the mark's or not critical.The reason I suggest this is becouse of the missalignment of the part you speek of.Look for bent bolts or oval shaped holes.Also look for scuffing where parts may have been run loose together.Be meticulous,it is your life on the line.Regards SonnyIntelligence is not a privilege,it is a gift and should be used for the good of mankind.

[birdy]

Fa cristsake Mitch, I'll throw you a grand to help ya git a proper set o blades.[ no, I'm not kid'n.]Ignorance is bliss............but only till you realise you were.Ingratitude stinks.......be generous carefully.

[Greg Mitchell]

Ok Fellas,Turns out me being a dickhead and all, when I measured up for bolt replacement, I must have included the bolt head. All bolts are 1/8" to long. Got the blades and hub bar set up to do the job to be confronted with my own stupidity.Now the Girl is worried and not keen for me to fly until I do the change. Thing is even though these might be original hardware nearly 30 years old, it all looks good, just thought I'd change all the hardware to ease the mind. (more hers than mine.)Sonny,How are you Mate? We will be doing a face to face soon, looking forward to that. The pillar block to hub bar isn't showing any signs of movement at the mating surface, all hardware on hub bar looks good and clean. There is a slight brown stain on the head of a bolt on the root of one of the blades, which was why I considered changing out all the associated hardware. These bolts look like they have been loctited, especially at the nuts. (non-castellated)Thanks for the tips. See ya soon. Mitch.Birdy,Thanks Mate, just make that chq out to.......I'll get a proper set after that first 50 hrs you mentioned in another thread. In the mean time Keith has a set of rotorhawks at 23 foot, heavier (up around Patroney and AK's weights) and I recollect a slightly wider chord. Keith would swap them for my Bensons in a heart beat. I dont know how easy the rotorhawks are to hand spin but I reckon I'll give them a burl. They are in mint condition. Thanks for the offer Buddy but I know how expensive boarding schools can be, you'll be needin all that loose change.Cheers,Mitchwww.thebutterflyllc.com

[asra]

Those Rotor Hawks hand spin nicely Greg. I ran them on my VW in the early 80's at 2.3333 degrees of pitch. A little more difficult to hand start than at 1 degree (factory setting). One and a half degrees was great for hand starting and performance. More efficient than your Bensens but probably less than Patroneys AKs or DWs.Aussie Paul.[8]www.firebirdgyros.com

[Greg Mitchell]

G'Day Paul,Thanks for that, I'd heard from some that they are reasonable blades. I think Keiths aversion to them was simply their weight over and above Benson ply or alum blades.Regards,Mitch.www.thebutterflyllc.com