Hobbsy

My Feedback: (102)

http://www.rcuniverse.com/market/item.cfm?itemId=395280

Michaelh

My Feedback: (4)

Here Ill post this here too . The Saito .82a with Turbo Header ,hovering/harriering.

http://www.vimeo.com/1109195

balsaeater

excelent link

I am very happy with my Saito 180 on zero nitro 20% EDL swinging a APC 18*6w except is TAD more noisy than I expected
( I am mostly electric fly )

The plane is a 1400mm 52 inch Graupner Ultimate meant for 120 4 s motor hyper light ~4kg ~10lbs and performs well 3D hovers at
~ 2/5 gas or mayby even 1/3

but I think as I rarely use more than 3/4 gas as there is gobs of power to spare except some few punch out events with full gas and I would prefer to get most sound supression solutions that exist as that increases the amount of flying feilds I can use


balsaeater

AJsToyz

Do not expect to much from welding,thats what I do for a living,and RC parts are so small that it won't be to promissing. Everything is so small, and the cast metal will pose a problem ,the porosity will tend to hold oil, then you still ned a drill and tap for the intake.

w8ye

My Feedback: (16)

The casting material used in the die castings of model engines has a high zinc content so the aluminum will fill out all the little intricate details of the casting design.

Aluminum castings with a high zinc content do not lend themselves to being the most weldable of metals. What the welder experiences is, that to get the metal hot enough to get any penetration, you will be within a hair breath of the whole thing melting into a puddle or at least a hole melting in it. The solution to this problem is to use a low melting point "solder type weld metal" which, as a result, does not have the strength of the original metal.

In the case of the previously mentioned Saito 150 and 180 cylinder castings, you can not just weld or solder the broken piece back on. The area would have to be welded up and re-machined with the original broken off piece not being used as such.

Most of our model engines are die castings. Some of the low production and one-off racing engines may have sand cast crankcases. These would typically be of a more weldable (356 prime) alloy with only 2.5% zinc and be much stronger with 2.5% copper.

I'm sure this will spark up some counter points from some metallurgical weld engineer and the discussion is welcome.

rexracer

I hope that something like this will work. When looking into aluminum repair, I found this site. http://www.aluminumrepair.com/aluminum_repair.asp It says it only needs about 735f for the rod to flow, and since I didn't break of any pieces, I'm hopefull. I watched a video of them brazing a butt joint, and then beating the heck out of it with a hammer, and it looked pretty strong. I'll go talk to a guy today and see what he thinks.

w8ye

My Feedback: (16)

There's a catch-22 The aluminum rods cost $65 for a 1 pound starter pack and then you need a torch. They say Mapp Gas but from my experience, the Mapp Gas torch has too broad of a flame for this application. You will need a small acetylene torch.

rexracer

I'm hopeing the guy I'm going to see today is familiar with this stuff, and can do the job. We'll see. I can always buy the new jug if it doesn't pan out.

w8ye

My Feedback: (16)

That's right.

Have at it Rex.

Hobbsy

My Feedback: (102)

Jim, I put the custom TurboHeaders on the TS .90 today and ran two 10 oz tanks through it, good news and good news, the pressure taps worked out perfectly and the rpm with a Bolly 13.5x6 is 9,750, 1,650 rpm idle is doable, kinda lumpy but it doesn't quit. Good job and Thanks for indulging me.

AJsToyz

Rex,

Just don't get it to hot, the temperature difference from the rod to the base material is usually only about 50 degree's. Soak your part in alcohol or some sort of degreaser for a while then let dry out. I have tried a few of these repair rods, and for something like this , it might be worth the effort.

Andy

rexracer

According to the website. the HTS-2000 rods flow at about 735 degrees, and aluminum melts at 1200+. I watched the videos and I'm tempted to spend the $65 whether I repair this or not. I do a lot of stuff with aluminum, and it looks like this stuff would come in handy.

waterloged

I used some of this a while back, it is touchy but i used it on my small boat motor and it's still holding today. I broke the choke mount off and it gets a fair amount of vibration to boot but like i said its still there. you want to clean the aluminum good before useing the stick. It was not the best looking job i ever did but it worked.

RC Specialties

Hobbsy,

Your installation looks great. I am glad the pressure tap modification worked out for you. I would still love to hear how it sounds.

Jim

rexracer

I'd like to hear that one , too. Do you have a plane in mind for it? On another note, I ordered some of those hts-2000 rods and, after some practice and testing, I'm gonna try to repair it myself. If it works, I'll run the engine on the stand for 1/2 hour or so, and see how it holds up, and if all is well, I'll fly. If not, I'll buy a jug. With all the stuff i use aluminum for, an easy way to "weld" it is just too good to pass up. I'll definitely post pictures of the proccess.

Capt Lou

Guys:

I have a Saito 1.00 and I adjusted the valves for the first time after about 3-4 gallons of fuel and have a question about this experience. My question deals with the fact that when I removed the valve cover, I noticed that one of the pushrods had come out of the base of the rocker arm screw and was pushing on the rocker arm and activating the valve. This provided low compression. I visually checked the pushrod and it did not look bent so I put it back into the screw base and adjusted the valves accordingly. I hand cranked the engine and it now has good compression and appears to turn over well. This is my first experience in adjusting the valves and my question is: does this occurence generally happen and should I be concerned about any damage that I cannot visually observe?

TimC

Jim, let me add my limited experience with welding cast aluminum. I would vee out the crack and make what looked like a good weld. As the weld cooled it would crack. My solution was to make the vee a larger angle than normal and weld. After it cracked, I would re-vee at a normal angle leaving weld metal to weld on. This time the weld wouldn't crack. I've welded aluminum engine cases but nothing as small as our airplane engines. I think this would pose a challange with a heli-arc rig. I also am hoping one of our members with experience with cast aluminum welding will post.

Vince J

My Feedback: (1)

Hi,
My buddy gave me his Saito .45 before he passed on. It's a MK2 version with no manual or any information on the engine or how to run it. There's a note on the box that says, "Adjusting nut needs replacing."
1. I know nothing about 4 stroke engines and the feeding and care of such pets. Obviously I need to get a manual to start me out a parts manual to indicate what is the adjusting nut and a place to buy such an item.

2. Is this information available in the archives? How does one research the archives? There are over 400 entries in the archives and I'm too old to spend that much time there.

3. How does one join the Saito club?

I'm also interested in those aluminum repair rods. A very interesting forum indeed!

w8ye

My Feedback: (16)

The adjusting nut that comes to mind is maybe a valve lash adjusting lock nut on a rocker arm?

Here is the current Saito engine manual for the smaller single cylinder engines. The 45 is no longer available but many of the parts with the SAI50xxx part numbers will fit a 45

http://www.horizonhobby.com/ProdInfo...der_Manual.pdf

Vince J

My Feedback: (1)

Thanks, i'll get right on it.

I graduated from the Sandstone Subnormal-With Honors!

Hobbsy

My Feedback: (102)

You be talking about this guy, I think I have the paper work. Let me know if you anything from it.

blw

My Feedback: (3)

Vince- you are now member #596

rexracer

I also have two Saito .45 MKII's, one that I got "new in box" and have all of the paperwork for. I must say that the early "manual" wasn't anywhere near the quality of the later ones.
Capt Lou, I'm no expert, but if you don't see any visual damage, you're probably OK. I wouldn't think the pushrod would pop out unless the valves were really loose, or the valve is sticking, so you might want to check for sticking valves.

Mode1Mike

Hey Hobbsy and w8ye...thanks for the links and advice on my 62a!!!

Mike

proptop

My Feedback: (8)

I think if you could find a way to keep it from cooling down too quickly, the chances of cracking would be lessened...
My dad was a welding engineer, and told me that Alum. (generally ) needs to be pre-heated, and the cool down after welding needs to be controlled.
If we were talking about a model engine case (or other parts ) for example, perhaps putting the case or parts in an oven before and after welding/alumabrazing, etc. would be a good idea?