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View Full Version : octura coupler 6mm to 250 flex help



Paul21
02-12-2014, 07:04 PM
hi i have the 67 inch hpr ct04 build thread well went to test today finaly after oh say 3 or 4 yrs had health issues but any way i decieded to run the setup on 6s to test everything out then later like next month get more batts and run 12s well i started the test made a slow start then half throttle pass then two full throttle passes the first seem to be quicker than the second and the third pass well really slow and notice only on roster tail so brought boat in and well both coulplers were evidently slippin as they were hot and i know i had them tight is there a trick to getting these things to hold i mean glad i wasnt on 44 volts as 22 volts made em slip any ideas other than maybe take off and cut the slots so i can tighten even more or is there a trick i dont know stumped

martin
02-12-2014, 07:39 PM
That can be quite a common problem on collet couplings where the coupling is as tight as it will go but flex can still slip. The problem is called galling between the 2 parts of the coupling where theirs metal to metal contact, using anti seize compound on the thread & taper prevents galling allowing the coupling to be tightened more. This is off course assuming your using the correct diam flex to coupling size.

Paul21
02-12-2014, 07:50 PM
yes sir i have 250 flex and a 6mm by 250 coupling so u think it the threads on the nut screwing on the coupling seizing before it actualy tigh on cable is what i interpit am i correct thanks

martin
02-12-2014, 07:55 PM
Yes its the threaded nut part of the coupling tightening onto the main part of the coupling, a number of people on this forum swear by using anti seize compound. Sometimes you can also have a flexes that are slightly undersize by a few thou that also don't help with slipping.

olwarbirds
02-12-2014, 07:56 PM
Paul, these are pricey but I promise you wont have anymore slippage probs...Ive been using them on all my 6S and up without a single prob.... http://www.rocketcityracing.com/MBP-Collet-Clutch--6-x-63_p_1711.html ...6.35mm is .250 hope this helps... DJ

Paul21
02-12-2014, 07:57 PM
i definately will check the threads also i read somthing about putting solder on end but i didnt do that as i didint want any heat to change temper and possible break of cable as i also have a big gas hydroplane and its flex cable always breaks right at outdrive wher i solder it to outdrive shaft so was oncerned with this build didnt use any solder now the joint on outdrives i used 658 loctite and its like 1 inch deep socket it good and fixed there an i thought that would be a problem turns out that is strong and the motor coupler is slipping .

Fluid
02-12-2014, 07:59 PM
The threads on Octura's couplers are quite rough. Much of the force you put into the wrenches is wasted overcoming friction. The use of an anti-seize lubricant on both the threads and the conical surface eliminates most of the friction so the force you put on the wrenches is used to actually tighten the collet. It makes a big difference.

The MBP couplers are very nice but pricey. IMO as long as you Octura coupler runs true it is good to go. Realize that you probably overheated the coupler and the cable when they spun....their temper could have been affected.



.

Paul21
02-12-2014, 07:59 PM
oh didnt realize about the cable might be little small will mic and if so i will wrap with brass sheeting to ake up difference thks again

Paul21
02-12-2014, 08:05 PM
olwarbirds i checked out the ones you suggested if i caint get ones i have to work then those will be next tks

martin
02-12-2014, 08:06 PM
Re soldering the end of flexes, some like to do it whilst others don't. If soldered correctly the temps will not affect the temper of the flex, how ever if you use a blow torch to solder which some do you have to be care full with not getting to hot.

Paul21
02-12-2014, 08:09 PM
hey also check out my build hpr ct04 67 inch cat will be posting updated pics of inside hull mine isnt as awsome as some of the other guys ive seen here but well i did everything myself with a hand held grinder and dremel not the pretiest but hope it will hold up for the long haul

Paul21
02-12-2014, 08:11 PM
yeah martin think that is my problem see i just caint seem to get all the grease out of cable end so have to heat enough to get greas out with flux paste i get about five tank fulls on the hydro and it snaps

martin
02-12-2014, 08:18 PM
Gas or nitro motors seem to be harder on flexes, electric motors are much smoother & kinder to flexes in my opinion.

Paul21
02-12-2014, 08:23 PM
i hope so i plan to run this boat often one i order some new batts i found some 6s 8000mah for 100 dollars so gonna order 4 to start so i can run 12s 8000mah have little run time and eventualy will be 12s 16000mah then lots of run time if doesnt weight down hull to much

olwarbirds
02-13-2014, 09:31 AM
i hope so i plan to run this boat often one i order some new batts i found some 6s 8000mah for 100 dollars so gonna order 4 to start so i can run 12s 8000mah have little run time and eventualy will be 12s 16000mah then lots of run time if doesnt weight down hull to much

Paul, pls post a link to those Lipos, Im needing some 6S myself and thats a good price...DJ