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General control line discussion => Open Forum => Topic started by: Andrew Borgogna on December 24, 2007, 01:43:01 PM
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Yesterday I took the Zilch out for the first time, I was able to get a couple of flights in on spark when the spark stopped working. I continued to fly on glow with the expectation I would resolve the problem today. Well I got troubles in River city. First thing I did was put an ohm meter across the points and turn the prop over expecting to see a dip in the meter when the points opened. They never opened, so I removed the prop and front cover to the points and looked to see what was wrong. If it is what I think it is the repair will require someone with more engine skill than I have. Surrounding the crank is a brass or bronze cylinder that has an opening machined in it that exposes the flat spot on the crank which is suppose to open the points. The brass part is fixed in the points housing and the crank rotates inside it. There appears to be a spring piece of metal that should fit in the machined out area and ride on the crank and work the points. Some how the machine out area of the brass part is at the 5 o'clock area and the spring is at the 10 o'clock area almost directly opposite each other. Since the spring is fixed to the points housing there is no way it could have moved, so it must have been the brass part that rotated inside the housing.
This will require disassembling the points mechanism and reposition the brass part and correct what it was that allowed the part to move in the first place. I have neither the tools or the knowledge to do this kind of work. Is there anybody out there who can or knows somebody who can. If I can't get this resolved I will have to give up on flying ignition at VSC this year. I guess I could take it back to MECOA for repair but I have reservations on doing that, they built the motor in the first place and must something that allowed the problem to occur. As always any help will be greatly appreciated.
Andy
P.S. I am including some pictures of the inside of the points housing I tried to get the lighting so you can see the brass part around the crank with the area machined away to expose the crank. Notice where the opening is and where the points are. This will never work.
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Thank you Marvin Denny! I just got off the phone with Marvin and the problem is solved a lever arm that should come down from the lower portion of the points and ride inside the opening in the brass sleeve is missing! It seems this part is made from very hard steel and makes a 90 degree bend at the upper pin and they have a bad habit of breaking at the bend. Now I need to get myself one or more of the parts to repair the points. I will call MECOA first thing Wednesday morning and see if they carry the part, if not I will try Meca and see if any of them have or make parts for this engine. If that doesn't' work out well I guess it's glow :-[
Thanks again Marvin.
Andy
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Andrew; MECOA (RJL) should have points for your Forster. I purchased a complete timer from them a few years ago for mine. If for some reason they do not have one, you can get one from Woody Bartelt at Aero-Electric.
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I went down in the basement and dug out my Forster 35, spent an hour figuring out the difference in your motor and mine, and my reply didn't transmit. But not only is Marvin good, he is fast!
The RJL brochure calls the part you're in need of the "moving point" assembly. $8.25 in 1991.
Good to have more Sparkers at the VSC, see you there,
dale gleason
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Out of curiousity I dug around on the Mecoa/RJL website. Finding the parts listing that actually shows availability is something of a pain. https://shop.mecoa.com/shopdisplayproducts.asp?id=106 should take you to the page directly. Also Aero Electric shows the moving point for the Forster for $10, but of course you'd have to check with them for availability. http://www.woodysengines.com/
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Thanks Andrew, I really didn't hold out too much hope for Mecoa after sales service does not seem to be big on their list of things to do. I tried to get a needle valve that was left out when they shipped the engine. They didn't have any and didn't know when any would be available and really didn't seem to concerned. At the time I just replaced the NVA with a ST NVA and got around the problem. This is a little different, I will give the people at Aero Electric a call tomorrow and find out if they have the part and if so place an order. Larry Renger and if have discussed the issue and if worst comes to worst I will install a Hall Effect electronic pick up and fire the ignition module that way. If I can get an accurate plan with dementions for the part Larry believes we can make the part with his machining equipment. I will do everything possible to get this problem resolved.
Andy
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I just contacted the Woody's models (Aero Electric) and they have the part in stock (Great News!). I will put a letter in the mail tomorrow. I described where the break ocurred and he confirmed that's where they all break he also said his do not break because they are made from Beryllium (sic) I guess its strong stuff.
With a little luck I should be able to have this all together well before VSC.
Thanks to all for your help.
Andy