isaacslaw

My Feedback: (4)

Ahhh gentlemen! DHL just dropped off my 82. What a sweet piece of work! It's just not the same looking at pictures on the net. Something about a new engine in the plastic wrap just makes me happy.

Anywho, I also purchased a velocity stack for it and a right angle muffler adapter. Imagine my surprise when I open up the adapter and find a note inside saying it was only for the flex header and I'll break it if I put the muffler on it! It would have been nice to know before ordering it and shipping half-way around the world. Oh well I have it in mind to use it anyway and maybe put some zip ties along the muffler to support the weight. What do you guys think? Am I just asking for trouble this way?

balsaeater

Man you are the prop man
I think the question is what prop you don,t have ??

On smaller engines I have always re trimmed the props and rebalanced them no issues
BUT THEY WERE NEW NO PROP STRIKES
just cut down to suit my needs with cut down of 25% of the blade if necessary
Also with a few pointy APC where the tip was knocked off in a prop strike I have done a retrim and re-balance but it would be like 5% loss of prop so 1/4 inch or maybe 1/2 inch but it is seldom as most prop strike break a blade clean off

Forces on smaller props even with higher RPM are much smaller so more things can be done than larger props

After 12 inch the forces are getting interesting and in flight or ground running shed blades can be very interesting events

The bigger problem for the bigger engines is the now trimmed down smaller props might go a lot faster in RPM and the props will have a MAX RPM rating so this might be exceeded

Often the prop strikes on the larger plastic type props have caused hairline cracks in the props so that is a risk to consider

On wooden or carbon fiber glass carbon blades I would not chose to re-trim them as they often for sure are seriously damaged from invisible hairline cracks from a prop strike

On electric I will go to re-triming new props up to 16 inch but for glow I tend to stop at 12 inch and bin the broken props of 16 and 18 inch if they have prop strikes

My solution for tricky landing places that will very likely break the props is is cut the engine high up and glide in but I do a lot of gliders and electric planes slope soaring so I don,t seem to have so many issues such as bringing in Ultimate Biplane in a high speed dive glide and last second flare but landing tend to be harder on the UC and sometimes need bending back but its cheaper than a $50 prop

Nowadays my usual solution is to replace a Saito 120 engine with say a Saito 180 and turn the biggest low pitch prop preferably 1/3 the wing span of model so as to have gobs of air passing over the wings even without flap assist and landing can be done a really really slow speeds and reduces prop stike events
So I alway way way grosly over power every plane and then I tend to get the same affect that eletric planes have a huge big prop that means plane follows propeler and nudging the gas plus or minus a tad with less risk of follow through make landing a more simplex event

Now all I got to figure is how to a 3D hover and grab the plane from the air and save the props and UC but might need good gloves to protect the fingers if it goes pear shaped


Balsaeater

RC Specialties

Issac,

I strongly suggest you secure the muffler. If the 90 breaks, which is a good possibility, you won't loose the muffler.

As for trimming props, the scale guys at my field trim the props forming a round tip all the time and have no problems. I would be very careful trimming a prop strike blade due to unseen cracks, as mentioned.

Jim

TomCrump

I've been searching for a link to the 450 radial manual, without success. Does anybody have one?

blw

My Feedback: (3)

xlr82v2 you are #605

rexracer

Well, I made the repair to the intake boss on my 1.80. it looks good...I'll post pictures soon. i took everything off of the cylinder and removed it because i was worried about the heat killing the valve springs. I was going to put it back together today and test it on the stand, but it looks like that's going to have to wait. While I was putting the valves back in, guess what happened. Thats right, i dropped one of the valve spring retainer halves, and i can't find it. That will teach me to work over the edge of a messy bench. i searched for about 15-20 minutes...no luck. I guess I'll have to order some more, unless someone happens to have an extra they would like to donate? Either way, it will be a while before I get it running.

rexracer

Here's a shot of the repair. You can see the original crack in my post on page 436 of this thread. I ground out a "V" along the crack, and used a mapp gass torch to heat it up. Tinned and filled it with the HTS-2000 rod, and filed it smooth after it cooled. They say the "weld" is stronger than the base aluminum. It's definitely harder I'd say...just by the way it filed down. It acts like a hard solder when using it. I'm going to do more testing with this stuff, now that I have it. I think I'll grab an old motorcycle brake lever and cut it in half, and butt-weld the 2 halves together and see how it holds up to a hammer[>:]
If anyone does have an extra retainer half, and is curious about the HTS-2000, I'll trade a couple of rods for one. So far, with 2 tests, and my repair, I've used about half a rod.

w8ye

My Feedback: (16)

Get the magnet out and find your valve keeper

The weld looks good

Michaelh

My Feedback: (4)

Excellent!

rexracer

I tried that. I think it may have bounced under the bench...and my work area is a mess right now. All I found were metal filings.

xlr82v2

My Feedback: (1)

Go ahead and order some new keepers... you'll find your old one right in front of your nose shortly after you get your engine assembled with the new ones.

... At least that's how it always works for me. Order a replacement, and finding the old part is virtually guaranteed shortly after replacement with the new part.

TimC

Or, out of stubbornness, try to install the new part in the same way as the lost part. Then the new part goes off to join the old part.

w8ye

My Feedback: (16)

When you get a keeper, assemble it in a clear plastic bag. If it pops away, you have it in the bag.

Jm

GaGeeBees

My Feedback: (23)

Excellent tip. Thanks w8ye!

rexracer

Now you tell me. I usually do stuff like this on a CLEAN bench with a large towel underneath the piece just in case I drop a small part. I guess this is what you get for being sloppy.

GaGeeBees

My Feedback: (23)

Here's a link to a short vid of one of my 2.70 twins. I love how easy these twins start. Prime and one flip is all it ever takes. This one has always made an odd sorta high pitched sound when it runs. Possibly something to do with the air bleed carb?

http://rcuvideos.com/item/9B4N02CDT0NSWX3H

w8ye

My Feedback: (16)

The high pitched sound may be a bearing?

xlr82v2

My Feedback: (1)

I agree... you've got a rough bearing. My ST S61K sounded exactly the same way before I replaced the bearings in it. I thought it actually sounded pretty cool for a while, but it eventually got worse, as yours will too.

rexracer

Looks like you get to disassemble your 2.70 and put new bearings in. Lucky you! I love tinkering with these things, even if I do make things difficult once in a while.

Michaelh

My Feedback: (4)

My .82a sounds exactly like that. Problem solved. Thanks Guys!

GaGeeBees

My Feedback: (23)

Funny... I don't feel lucky Ought to be interesting though. I'll keep y'all posted on what I find.

Meantime, here's another short video of my Saito 1.70 radial.

http://rcuvideos.com/item/VS9YGMFMQHV2RYWD

w8ye

My Feedback: (16)

The real bear to put bearings in a twin is the Saito 60T or 90TS. They have 4 mains and 3 cam bearings. Plus the rod caps on the connecting rods are critical enough at disassembly but at reassembly they have to be placed upside down on the crank in one position and then the crank rotated almost 180 degrees whereas the rod is mated up to the cap and the rod bolts tightened. Four of the bearings are in blind pockets.

bgfireman

My Feedback: (13)

How do people get where they can hand flip there engines to start?
Alan

rexracer

Most Saito's hand start pretty easy. I think the key is in the prime. They need to be good and wet, then backflip (clockwise) against compression. They'll kick and start counter clockwise. Though I have hand started most of my engines before, I usually use an electric starter. It just seems safer to me, and works easily hot or cold.

Krener

Hey all, wondering if someone can help me.
I've got an FA 72 that I'm wanting to put a flexible exhaust extension on to keep the front end of my SSE tidy.
I have a right angle adapter so it will run nice and tight along the side of the engine, but is there a st length that flexible extensions have to be, or is it personal discretion?
And does the standard muffler have to be fitted at the end of the extension, or can it be left as just a long piece of pipe.

Thanks in advance.