Welcome to Club SAITO !
03-29-2006, 03:21 PM
#2553
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RE: [Awaiting Approval]
Saito member #222 here.
Loaded my Saito 220 on a test stand at a fellow modellers place last night. All I can say is ...HOLY CRAP!! When he advanced the throttle...nowhere near full...it actually started pulling the test stand. Awesome power. I found it amazing that there was virtually no vibration. Is that typical?? My Saito .82 vibrates quite a bit...is it a combination of poorly balanced prop and weak firewall or what??
Loaded my Saito 220 on a test stand at a fellow modellers place last night. All I can say is ...HOLY CRAP!! When he advanced the throttle...nowhere near full...it actually started pulling the test stand. Awesome power. I found it amazing that there was virtually no vibration. Is that typical?? My Saito .82 vibrates quite a bit...is it a combination of poorly balanced prop and weak firewall or what??
03-29-2006, 04:15 PM
#2554
RE: Welcome to Club SAITO !
ORIGINAL: N3OKI
How is the .40??
How is the .40??
03-29-2006, 07:00 PM
#2558
RE: Welcome to Club SAITO !
Jim, I had a .30 os on it and craved a little more oomph. When I bought the plane used, it had about 12 ounces of nose weight added. The .40 flies it nicely and I wouldn't say it's overpowered at all. I was able to eliminate the lead weight.
03-30-2006, 02:19 AM
#2561
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RE: Welcome to Club SAITO !
All:
Just made this post in another thread, it's something that is often forgotten. I think it's an important safety thing, so if it's old news to you please excuse me.
On a four stroke engine, because of the potentially violent backfire, you should never use a spinner with a plastic back plate, one pop and the prop can come flying off.
If you want to go cheap, there are several on the market with aluminum back plates and plastic cones, these should be your last choice other than the price. Using an electric starter you can have the cone shatter, if you hand start they will generally be OK.
The best is an all metal spinner.
Lowest priced ones are "Spin-Right," available from Cermark, your LHS, and others. The Spin-Right have some parts in some sizes cast, this makes them more prone to shattering in a crash where others might just bend, and allow straightening. Also, I have never gotten a Spin-Right that was not badly out of balance. This needs to be checked before mounting on the engine. Available in two and three blade cuts.
I have never used a Dave Brown spinner, but what I've seen seem to be of good quality. They have a fully machined back plate, the cone is formed by "Spinning" the metal. Since it is spun aluminum the metal has to be soft to allow the forming. The DB "Vortech" spinners are available in standard two and three blade cuts, or with special cuts for any propellor you want. Available direct and LHS.
The best of the lot are the "Tru-Turn" spinners. They are fully machined so they can use harder alloys than Dave Brown, and using the better alloys they are stronger as well. And they are light. I was very surprised to fine a Tru-Turn 2 1/2" three blade standard spinner was lighter than a Du-Bro plastic three blade spinner of the same size. You will pay for them though. pair of 2 1/2" 3b spinners with adapter nuts is close to $100 at your door. Standard cuts will cost less.
Bill.
Just made this post in another thread, it's something that is often forgotten. I think it's an important safety thing, so if it's old news to you please excuse me.
On a four stroke engine, because of the potentially violent backfire, you should never use a spinner with a plastic back plate, one pop and the prop can come flying off.
If you want to go cheap, there are several on the market with aluminum back plates and plastic cones, these should be your last choice other than the price. Using an electric starter you can have the cone shatter, if you hand start they will generally be OK.
The best is an all metal spinner.
Lowest priced ones are "Spin-Right," available from Cermark, your LHS, and others. The Spin-Right have some parts in some sizes cast, this makes them more prone to shattering in a crash where others might just bend, and allow straightening. Also, I have never gotten a Spin-Right that was not badly out of balance. This needs to be checked before mounting on the engine. Available in two and three blade cuts.
I have never used a Dave Brown spinner, but what I've seen seem to be of good quality. They have a fully machined back plate, the cone is formed by "Spinning" the metal. Since it is spun aluminum the metal has to be soft to allow the forming. The DB "Vortech" spinners are available in standard two and three blade cuts, or with special cuts for any propellor you want. Available direct and LHS.
The best of the lot are the "Tru-Turn" spinners. They are fully machined so they can use harder alloys than Dave Brown, and using the better alloys they are stronger as well. And they are light. I was very surprised to fine a Tru-Turn 2 1/2" three blade standard spinner was lighter than a Du-Bro plastic three blade spinner of the same size. You will pay for them though. pair of 2 1/2" 3b spinners with adapter nuts is close to $100 at your door. Standard cuts will cost less.
Bill.
03-30-2006, 07:15 AM
#2562
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RE: [Awaiting Approval]
Bill.. You ain't kiddin'!! I had one of the alluminum back plate with plastic front and hit it with a starter one time and the engine backfired and the plastic hit me in the head.. LUCKY.. I>> HAVE<< A)) HARD:: HEAD!!!LOL!!!
I got the bearings in from RCbearings.. They look great.. BUT They are WAY off in size.... DARN IT!! I am going to send them back along with my old ones so they can match them up . The front and rear bearing were way off size. The inside is perfect but the outside on both bearing are WAY too small.. Anyways,,, just wanted to let ya'll know. 3 sets of bearings for the 120!! WOW!
LATER
I got the bearings in from RCbearings.. They look great.. BUT They are WAY off in size.... DARN IT!! I am going to send them back along with my old ones so they can match them up . The front and rear bearing were way off size. The inside is perfect but the outside on both bearing are WAY too small.. Anyways,,, just wanted to let ya'll know. 3 sets of bearings for the 120!! WOW!
LATER
03-30-2006, 08:19 AM
#2563
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RE: [Awaiting Approval]
Hey guy's thanks for the info on the 40. I think after the 2 larger (65in span) profiles are built I will order in a 40 and build the 25 size MoJo. Should be neat to have a small 3d plane.
The wife thought i had lost it yesterday, when upon arriving home from some honey do errands she looked out and saw a new 6x10 enclosed trailer attached to my vehicle. She did not go for the "it followed me home. Can I keep it?" line. So i had to tell her the truth. Hit a hell of a sale att the local Lowes. 2000.00 on sale. They miss priced it. Priced as a smaller trailer. Bt the manager gave it to me as priced. I could not pass it up.
The wife thought i had lost it yesterday, when upon arriving home from some honey do errands she looked out and saw a new 6x10 enclosed trailer attached to my vehicle. She did not go for the "it followed me home. Can I keep it?" line. So i had to tell her the truth. Hit a hell of a sale att the local Lowes. 2000.00 on sale. They miss priced it. Priced as a smaller trailer. Bt the manager gave it to me as priced. I could not pass it up.
03-30-2006, 01:46 PM
#2564
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RE: Welcome to Club SAITO !
Hey Bill
I just tried to install my SAI50GK93 intake stack on the .91s. There is a problem with the carb mounting bolts , I can only get one or the other bolt to pass throught both holes on the intake stack. Just a very tiny bit too off ( I tried to put some pressure on the stack to align it but it just will not quite fit)
Now also, there will be an opening on each side parallel to the bolts at the carb intake so It is going to draw air from both sides of the base of the intake stack. The stack seems to slide over the carb correctly but I wonder if the slits are supposed to be there? May be the mounting holes are just slightly off? I could redrill the mounting holes a bit but I dont know why the intake should have "air leaks" on both sides.
Sorry for such a rambling question but Im having a hard time explaining. Can you advise?
Thanks
Bill
I just tried to install my SAI50GK93 intake stack on the .91s. There is a problem with the carb mounting bolts , I can only get one or the other bolt to pass throught both holes on the intake stack. Just a very tiny bit too off ( I tried to put some pressure on the stack to align it but it just will not quite fit)
Now also, there will be an opening on each side parallel to the bolts at the carb intake so It is going to draw air from both sides of the base of the intake stack. The stack seems to slide over the carb correctly but I wonder if the slits are supposed to be there? May be the mounting holes are just slightly off? I could redrill the mounting holes a bit but I dont know why the intake should have "air leaks" on both sides.
Sorry for such a rambling question but Im having a hard time explaining. Can you advise?
Thanks
Bill
03-30-2006, 01:56 PM
#2565
Banned
RE: [Awaiting Approval]
I have been using CB Asscociate Spinners for 25 years and the ONLY time I had them break was running into the ground. Hard on the plane too. They are also anything but cheap.
03-30-2006, 02:51 PM
#2566
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RE: [Awaiting Approval]
Bill:
From "Saito Notes:"
So I'm lazy, this way I don't have to type it again.
Bill.
PS: Didn't I send youo a copy? wr.
From "Saito Notes:"
Sealing the intake stack
I never said anything in particular about the o-rings, only that the gap between the carb body and the stack had to be sealed for it to work properly.
I've always been leery of using an o-ring in such a place, my preference is to cut a length of tubing that's a snug fit in diameter and length to go there, and dab some RTV on the outside of it to complete the seal.
What I've been told about the o-rings is someone taking the carb (or complete engine) and the stack to their local hardware store and just picking out one to fit.
My aversion to an o-ring here is for two reasons. One, the tubing will give a much smoother surface inside, the o-ring is either going to have two grooves or a bulge into the air flow, or both. Further, if the o-ring is loose it might not seal well, and it could work its way out of position and go into the carb. If it's clamped tightly, as the oil in the fuel works its way around the o-ring it might get squeezed out and get into the carb. I doubt it would hurt anything mechanically, but it could jam in the throttle barrel and be a fault that was very hard to find. Worse case would be causing a dead stick and still be a bear to find.
Of course you could find an o-ring that was a perfect fit, just lightly clamped, and it would work perfectly.
Sealing the intake stack – tubing
You will select a tubing diameter that will fit into the recess where the Teflon seal was fitted for the choke plate, and cut it to length to be a snug fit between the carb body and the flange of the stack. The picture is an old FA-80, the white ring is the Teflon seal. Its outer diameter will be 11 mm or 7/16" depending on which rack you visit.
And a small o-ring around the outside of the tube would probably make it as good as you can get. I'll try the outside o-ring on my next one.
I never said anything in particular about the o-rings, only that the gap between the carb body and the stack had to be sealed for it to work properly.
I've always been leery of using an o-ring in such a place, my preference is to cut a length of tubing that's a snug fit in diameter and length to go there, and dab some RTV on the outside of it to complete the seal.
What I've been told about the o-rings is someone taking the carb (or complete engine) and the stack to their local hardware store and just picking out one to fit.
My aversion to an o-ring here is for two reasons. One, the tubing will give a much smoother surface inside, the o-ring is either going to have two grooves or a bulge into the air flow, or both. Further, if the o-ring is loose it might not seal well, and it could work its way out of position and go into the carb. If it's clamped tightly, as the oil in the fuel works its way around the o-ring it might get squeezed out and get into the carb. I doubt it would hurt anything mechanically, but it could jam in the throttle barrel and be a fault that was very hard to find. Worse case would be causing a dead stick and still be a bear to find.
Of course you could find an o-ring that was a perfect fit, just lightly clamped, and it would work perfectly.
Sealing the intake stack – tubing
You will select a tubing diameter that will fit into the recess where the Teflon seal was fitted for the choke plate, and cut it to length to be a snug fit between the carb body and the flange of the stack. The picture is an old FA-80, the white ring is the Teflon seal. Its outer diameter will be 11 mm or 7/16" depending on which rack you visit.
And a small o-ring around the outside of the tube would probably make it as good as you can get. I'll try the outside o-ring on my next one.
Bill.
PS: Didn't I send youo a copy? wr.
03-30-2006, 03:13 PM
#2568
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RE: Welcome to Club SAITO !
And I failed to address the fit of the holes.
The parts are stamped out, sometines the bends aren't in just the right place. If you need to "Hog" the holes out a little to get a good fit, just do it and go. Nothing to worry about.
Bill.
The parts are stamped out, sometines the bends aren't in just the right place. If you need to "Hog" the holes out a little to get a good fit, just do it and go. Nothing to worry about.
Bill.
03-30-2006, 03:53 PM
#2569
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RE: Welcome to Club SAITO !
Bruce, I did answer it, you just didn't look in the thread where you asked. http://www.rcuniverse.com/forum/m_40...tm.htm#4096319
03-30-2006, 04:18 PM
#2570
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RE: Welcome to Club SAITO !
Oh, so you did. Still can't imagine a tach accurate to one rpm in 14,000 would affordable to anyone. Also no engine will hold RPM to one rpm. That's like significant figures or stating the national debt to the penny.
03-30-2006, 04:26 PM
#2571
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RE: Welcome to Club SAITO !
BruceL (and Hobbsy):
In order for any counter to be accurate to a untis count, it has to have a gate time, the counting interval, equal to the period being measured.
In other words, for a tachometer to be correct to ONE revolution per MINUTE it will have to sit there counting for an entire minute before giving a reading. Few people would accept such a thing.
What we actually have are devices that have a much shorter gate time, and obviously, less digits of precision.
If we use a six second gate we can have accuracy to ten rpm, six tenths of a second give 100 rpm numbers that mean something. People will put up with slightly less than two updates per second, this is where most model tachometers are set.
If the TNC has a selectable gate time, including a one second interval, it will then give meaningful numbers down to one rpm. I don't know if it has the option, but I doubt it.
And no tachometer can be any more accurate than the internal clock that controls the gate. This is where the major differences lie. If there's a pot for adjustment, to be set when pointing at a light, it's not to be trusted for extreme precision. Only a crystal controlled clock can be trusted, and even they will change with temperature unless there's a oven to keep a constant temperature on the crystal.
Please, no more carping about how mine is bigger/faster than yours - our measuring devices are not good enough for that sort of thing. All we can do is compare and guess.
Bill.
In order for any counter to be accurate to a untis count, it has to have a gate time, the counting interval, equal to the period being measured.
In other words, for a tachometer to be correct to ONE revolution per MINUTE it will have to sit there counting for an entire minute before giving a reading. Few people would accept such a thing.
What we actually have are devices that have a much shorter gate time, and obviously, less digits of precision.
If we use a six second gate we can have accuracy to ten rpm, six tenths of a second give 100 rpm numbers that mean something. People will put up with slightly less than two updates per second, this is where most model tachometers are set.
If the TNC has a selectable gate time, including a one second interval, it will then give meaningful numbers down to one rpm. I don't know if it has the option, but I doubt it.
And no tachometer can be any more accurate than the internal clock that controls the gate. This is where the major differences lie. If there's a pot for adjustment, to be set when pointing at a light, it's not to be trusted for extreme precision. Only a crystal controlled clock can be trusted, and even they will change with temperature unless there's a oven to keep a constant temperature on the crystal.
Please, no more carping about how mine is bigger/faster than yours - our measuring devices are not good enough for that sort of thing. All we can do is compare and guess.
Bill.
03-30-2006, 04:32 PM
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RE: [Awaiting Approval]
#237
mwarren400, I'm glad to hear the good news, I have a 220 and will be fireing it up this weekend for the first time. What size prop did you use? What kind of fuel?
mwarren400, I'm glad to hear the good news, I have a 220 and will be fireing it up this weekend for the first time. What size prop did you use? What kind of fuel?
03-30-2006, 06:41 PM
#2574
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RE: Welcome to Club SAITO !
William, that 1 rpm rpm idea came straight out of Bruce's left field not mine, and now you're out there too. I don't know where his question came from or why, I showed him my tach, that's it, no more no less. Lighten up my Friend.
03-30-2006, 07:01 PM
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RE: Welcome to Club SAITO !
Dave:
The tach post wasn't aimed at you, but rather at BL and anyone else who might be wondering why our tachs only read to 100 rpm increments at best.
Bill.
The tach post wasn't aimed at you, but rather at BL and anyone else who might be wondering why our tachs only read to 100 rpm increments at best.
Bill.