One little job becomes a Baker's Dozen.

[birdy]

Brian, apples n oranges mate.If your usen the wind to get your 200+ rrpms, then yes, you will need sum noise to stop the rotor pulln you back.But if your prespining in still air, past 200rrpm, the engine is generaly much higher than idle, so you need sumthn to stop it creepn forward, like ground breaks, or air breaks [ rotor].

[Brian]

Brian, apples n oranges mate.If your usen the wind to get your 200+ rrpms, then yes, you will need sum noise to stop the rotor pulln you back.But if your prespining in still air, past 200rrpm, the engine is generaly much higher than idle, so you need sumthn to stop it creepn forward, like ground breaks, or air breaks [ rotor].Yep, I understand what you mean but I wondered even in still air that the rotor at full backstick would produce more backwards thrust than the engine, specially at rotor revs greater than 200 revs.I also understand that some gyros state that stick is to be full forward until certain revs are achieved.Thinking about it, once prop revs get over 3500, engine thrust would probably overcome the rotor thrust.

[Greg Mitchell]

Once my engine was at 3700-4000 rpm the brakes were giving up and at full back stick the disc was not holding either.The expensive USA 1/2" MC"s arrived and the freight was a dear as the two MC"s. >Installed and so far have spent about 4 1/2 hours trying everything to bleed them.Followed the manufacturers instructions, and everyone elses.Ole Mate Nigel spent three hrs with me this afternoon and I had high hopes...... :"(I have less holding power than I got with the 3/4" MC which I could at least bleed enough to give me good feedback in the lever. I could not get this with the 1/2" MC.Emailed the supplier to advise and now I"m going to have to go and get "maggoted".Mitch

[birdy]

You got cows in tasy aint ya Mitch.Chuck a coupla their "chocks" [ dry ones] in frunt of the mains, itll never mooove. Yep, I understand what you mean but I wondered even in still air that the rotor at full backstick would produce more backwards thrust than the engine,If thats the case, not so much backstick then.I also understand that some gyros state that stick is to be full forward until certain revs are achieved.Yeh, that a Europein thing.

[Ken Watson]

Bleed back the front. Use a medical syringe and push the fluid back through the nipple on the caliper until all the air is expelled through the master and the reservoir is full. Trying to bleed the traditional way is for mugs. Ken

[joew]

Bleed back the front. Use a medical syringe and push the fluid back through the nipple on the caliper until all the air is expelled through the master and the reservoir is full. Trying to bleed the traditional way is for mugs. KenThat is a great idea, Ken!Another way I found that works is to fit a plastic tube onto the nipple and have the other end in a bucket with brake fluid(of course below the bleed point). Then open the nipple until fluid flows. Keep topping up the master cylinder until you do not get bubbles happening in the tube, then close the nipple. (It worked a treat on International MK5 army trucks in Shoalwater bay when you were in the middle of nowhere with minimal tools)Just a message for Birdy: Did the moderator jump on someone, from a great height, like our mate from Condobolin??

[Greg Mitchell]

It"s a mugs game anyway you look at it.We tried the maunfacturers instructions...from the top down. See attached.We tried from the bottom up as Ken stated.We tried a couple of our own methods.Didn"t spit the dummy or get Maggotted.Went up to the workshop after dinner and tried Larry"s method. Which requires using a gravity feed bottle above the upturned MC, so now the bleeder screw is on top and the discharge line is halfway up the cylinder.......Cracked both nipples and let bleed on own accord for 10 minutes. Did"nt see any air come out but when I nipped everything up I had twice the holding power I had previously. Ther is still air in the system and after tests this morning I will know more.Need to get off line as Hegar 4 Manufacturing are ring from the USA at 9 am.Mitch

[birdy]

Just a message for Birdy: Did the moderator jump on someone, from a great height, like our mate from Condobolin?? Dont tell anyone, but i recon Coondoblin was a pretty place.

[Tim]

Didn"t spit the dummy or get Maggotted.You disappoint me Mitch.I think both Birdy and Ken had it right. The efficiency (pressure) of the M/C is directly proportional to the surface area of the cylinder. A 3/4" cylinder has an area of 0.442 sq" and a 1/2" cylinder has an area of 0.196 sq" - less than half the area. Hence the 1/2" cylinder will give you more than double the pressure, at the expence of more than double the lever movement.Double the lever movement is no problem as long as you do not run out of lever travel.Always bleed from the lowest point to the higest point, even if you have to remove and "tilt" one (or both) of the cylinders to achieve this. As Ken said, you may have to force feed the system if the lines are particularly small in diameter.

[Greg Mitchell]

Hey Tim,I secretly did do the "dummy spit".

[Disco]

Mine were bloody tricky to bleed too. (hegear i think) There is air in them now but when i bled them the first or second time, they worked good.

[bosca]

Get a grip Joew.Go back to your barracks before I give you a DP.

[Greg Mitchell]

Good Morning Disco,I neglected to post the instructions.Are you using the old single disc "puck" brakes rated to 500 lbs or the real disc brakes rated to 1100 lbs?Mine are the later.The puck brake came out with 3/4" MC because it needed more oil volume to do its job.The 1100lb and the 1600 lb brakes use the 1/2" MC as std.

[Brian]

Good to hear that you are getting it sorted Mitch and its real pleasing to see that some good old fashioned service still is around!! Thank you Mr Hegar !!I would have assumed that all brake lines would be copper pipe. So there you go ! Guess the clear stuff is a lot lighter and being able to see the air would be a great help !!I had the opportunity to see the MLS on Allan"s gyro and its certainly a lot of pre rotator!

[Echo]

Mitch,
..........