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Member postings for GrahamWh

Here is a list of all the postings GrahamWh has made in our forums. Click on a thread name to jump to the thread.

Thread: Four stroke crankcase venting
05/11/2014 18:22:23

Hello All,

I have an old OS 70 Surpass which has a venting point at the bottom of the crankcase, and a new-ish ASP FS70 that has one by the camshaft which is plumbed to the inlet manifold. Both run okay, but when I replaced the bearings of the ASP recently I found some evidence of rust starting to form.

On the compression stroke and the exhaust-expelling stroke the crankcase of the OS Surpass sucks in air, but the ASP sucks in fuel mixture from the carburettor. Could the influx of fuel be speeding the rusting process - and is it a sensible thing to disconnect the breather from the intake manifold and plug the manifold, making it run like the OS?

Thread: Winter seems to have arrived, who's been flying?
03/11/2014 22:52:57

Got my repaired I/c Renegade up on Sunday. A bit windy but if we don't learn to fly on the windy days then we don't end up flying much in winter, so needs to be done. Trying a 3s LiFe battery with regulator instead of the old NiMH things that only have a small fraction of useable capacity for the receiver. Worked well.

Edited By GrahamWh on 03/11/2014 22:53:37

Thread: 2015 Mass Build - Nominations Chat Thread
03/11/2014 22:41:22

2nd round coming up?

Thread: Flycatcher
02/11/2014 20:09:17

I look forward to seeing another flight video Linds. It is rare to see such a fine looking, out of the ordinary model. It really looked great in the air too.

Thread: OS electric motors
02/11/2014 19:08:11

From what I read somewhere that I can not remember, I think the OS data uses a lab power source rather than an actual lipo, hence the voltage given as 12.6 volts on their tables, which would be a fully charged 3s lipo with no voltage drop. Official OS data here:

**LINK**

Thread: Flycatcher
02/11/2014 18:23:40

It really does look great. Is it possible that the plate behind the pilot's legs is acting a little like a down pointing elevator causing the long take off?

Thread: Any ideas ?
02/11/2014 17:51:47

I suggest you check the power down setting on the esc. If the trigger voltage is too high (say 3.5 v per cell rather than 3.2v) it may put the esc into low power mode too early. An old battery may give too much voltage drop at high current and trigger this. I have found with some of the many Turnigies I have bought that they are sometimes best treated as being of half the said C value.

Thread: OS electric motors
02/11/2014 17:44:37

I have just one bit of data on the OS 3820 1200 kv if it's any use. Measured using a poor lipo who's voltage dropped to just over 10v (a Turnigy of some description):

With an i/c MA 9.5x6 inch prop - 330 watts (30 amps), actual thrust measured using string and kitchen scales 1400 gram weight.

That's all I have sorry - I use it on a 50"Seagull PC9.

Thread: Fuel syphoning into carb
02/11/2014 17:37:57

Is the ASP inverted? If so, you could raise the carb by changing it to horizontal.

Thread: Engine test rig
01/11/2014 17:10:07

Also Steve you could have something like a tube to catch the oil and muck coming out of the crankcase breather nipple or your test bed will get coated in oil from there. Looking good.

Edited By GrahamWh on 01/11/2014 17:12:35

Thread: ASP 120FS
27/10/2014 18:31:37

Have a choke on my asp fs70. Never use it now - always stop the exhaust, very effective that way.

Thread: Crashed today, really annoyed with myself!
27/10/2014 18:28:35

Its October - plenty more bad wind days coming, few calm ones. I agree with flying it with the old fuse.

Thread: Stainless steel engine bearings
27/10/2014 18:19:22

Thank you all, I shall go ahead!

26/10/2014 14:58:08

I am going to replace the bearings in my ASP FS70AR soon as they have developed some play. I can detect some wobble when I pull one prop blade forward and the other backwards. I suspect the rear bearing is a bit loose.

One member of the club I go to recommends replacing with stainless steel, but I have read on one bearings supply site that stainless are not as strong as normal steel - can't handle as high a load. Are they suitable for model engine bearings?

Also I can only find a stainless one in the size I want with rubber seals. Is it okay to just prise off these rubber seals to make it into an open bearing?

Thanks guys, Graham.

Thread: OS 55AX Engine - crankshaft end float
10/10/2014 16:54:31

I have followed your advice ED, bearings replaced with a SS one at the rear and normal one at the front (with the inner shield removed as per the original for lubrication) all for £6 plus postage. Much quieter. Fired it up this pm and working smoothly. With a slightly rich mixture, it is turning a 13x5 MA K series prop at 2,400 to 9,600 (9,900 leaned out). Thanks.

Thread: HobbyKing Avro Lancaster V2
09/10/2014 22:04:49

Stock level currently at MINUS 6. Whoops, computer not keeping up with purchases perhaps. How long will the next container take I wonder?

Thread: 1st Round Voting Thread
09/10/2014 19:59:25

1. Pietenpol Aircamper

2. Bristol Scout D.

Edited By GrahamWh on 09/10/2014 20:05:34

Thread: OS 55AX Engine - crankshaft end float
29/09/2014 11:11:05

Thank you Martin. I'll keep an eye on it and I have ordered a new set for when it eventually wears out from RC bearings - a lot cheaper than OS!

28/09/2014 23:18:07

When pushed backwards, there is a slight grinding, but not if pulled forwards, as the prop will be. Worth taking engine back off and opening it up do you think?

Thread: Propellers...for beginners - please keep it simple
28/09/2014 23:13:46

KV is like the gearing.

Prop selection can be too.

If you put in a lower kv motor than you should have it will go slower so just fit a greater pitch prop to make up for it, and check the current with a watt meter. To be honest the example you give (900 from 2000kv) is a bit extreme - you'd change the motor for such a difference. Alternatively increase the voltage, double it, to make the motor try and spin the same speed as the 2000 motor would have done, provided the motor could handle the voltage, and keep the prop the same as the original, checking the current is still within your power train's limits with a watt meter of course.

Edited By GrahamWh on 28/09/2014 23:14:28

Edited By GrahamWh on 28/09/2014 23:15:26

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