I really think that is the answer for the rubber I was flying on the A6 but maybe not so much for the "for sure" 2107 rubber...but numbers dont lie and checking things twice, I have to say Don's formula is dead on: calculated 1026 turns...I could have miss counted those 2 winder turns and regardless FAR better than my expectation as far as predictions go.
Last night was a real turning point for me, flew a half motor to trim. Then worked my way up to 1800 turns on a 14" full motor(calculating 2524 to break) and while 3:30 was less than I've done before I actually got a proper type flight where the climb put me on the roof only a little early for cruise, a solid cruise and powered decent with turns left. Prior to this my lack of technique was getting me into long bumping sessions followed by dead stick landings from nearly the roof- I got 5 minutes that way but I now know thats not how its done.
SO a BIG thank you to Don S, NIck and all who commented.
-----Original Message-----
From: Nick Ray lasray_at_gmail.com [Indoor_Construction] <Indoor_Construction_at_yahoogroups.com>
To: Indoor_Construction <Indoor_Construction_at_yahoogroups.com>
Sent: Sat, 28 Apr 2018 12:04
Subject: Re: [Indoor_Construction] 2017 SS rubber
Steven,
I think we've solved the mystery. When plans reference an 18" motor they are referring to an 18" loop, or rather a 36" strand doubled over an tied. This is how they are able to get so many more turns. It is also why there is so much discussion out there on how to get A-6 motors to unwind.
Another issue is the range of variability between the two rubber thicknesses you have. .040" will take many more turns than 0.0625" (1/16") due to the thickness of the rubber. The .040" seems much closer to what Bill Gowen would likely use.
All the best,
Nick
On Sat, Apr 28, 2018 at 9:52 AM, Steven Whitecoff cross.up_at_verizon.net [Indoor_Construction] <Indoor_Construction_at_yahoogroups.com> wrote:
Don,
So as to not have any confusion on my end(being new to the technical discussion end of this), My motor is a single strand so that its knotted at 18" making a loop 9" long for a 6" motor stick. .040 stripped width, 0.72grams. This is what I flew with last night and did manage 1800 turns.
Someof my trouble is I was given some rubber which now seems to be much better than my purchased rubber, But I did not think to keep it separate from the purchased rubber, thinking it would only be a tiny difference.
Because I do not have a stripper yet I'm testing the rubber as supplied by FAI supply which is 1/16th inch, same length as above. I forgot to weigh it and know it will not take nearly as many turns but 1000 seems way low. I'll get a good weight on several pieces later and make sure I do as much as I can to follow tips given last night by the local F1D crew then let you know what the exact result is for the purchased rubber.
Consensus last night was bad rubber but I'll reserve judgement until I revisit the whole data collection process.
The rubber has been store in the original bag from FAI, never in sun at all, never over 80*. Ray Harland O-rings. Digital scale torque meter. 15:1 winder. FAI lube.
Thanks for taking the time to help.
-----Original Message-----
From: Don Slusarczyk don_at_slusarczyk.com [Indoor_Construction] <Indoor_Construction_at_yahoogroups.com>
To: Indoor_Construction <Indoor_Construction_at_yahoogroups.com>
Sent: Fri, 27 Apr 2018 19:07
Subject: Re: [Indoor_Construction] 2017 SS rubber
Something is not right, you should not be getting max calculated torque at only 300 turns into a motor that is supposed to take 3450 turns. What length and weight motor of TSS are you winding? Is it a digital or wire torque meter? How was this rubber stored? If exposed to direct sunlight it might just be rotted.
On 4/27/2018 5:07 PM, cross.up_at_verizon.net [Indoor_Construction] wrote:
So I find and load up Bill's 2010 data in Frash's spreadsheet and see I should be putting in 230 winder turns for my weight and lenght of rubber. Lubed with FAI lube, ArmourAll or Bill's fav, synthetic shock oil, I get the recommended max torque at 20 winder(15:1) turns and by coming in to the stooge and winding slowly I can get to 70 winder turns then BLAMMO!.
I've tried and tried to no avail to do better. I have worked the rubber by working up slowly from 30 winds over 10 sessions, I've tried low initial stretch, Bills recommended 5-6 length initial stretch and nothing seems to make enough difference to matter. I get rubber batches vary and 2010 might have been a good year but shouldnt I expect more than 30%. The kicker is the last of the "good" rubber had no issue going to 100 winder turns and I have no idea how much more it could take.
--
Don Slusarczyk
Received on Sat Apr 28 2018 - 20:51:08 CEST