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Hobbico Tach Readings Make No Sense

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Hobbico Tach Readings Make No Sense

Old 03-26-2007, 10:25 PM
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Bosch232
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Default Hobbico Tach Readings Make No Sense

I have a Hobbico tach that hasn't seen much use.

It gives completely unrealistic readings.
E.G.: I have a Zenoah G-45 that I ran tonight, and this thing was saying 13,000 rpm's. Yeah, right...
I changed the batteries, same results.

When I hold it up to a fluorescent fixture, it fluctuates around 10,000 or so, but will drift off to 12,000 randomly. It never zeroes in.
I don't remember what it's suppoed to read at a fixture, but I don't think 10k is it.
Would it matter if the fluorescent bulbs are new T-1's instead of the bigger older fluorescents?

Is this thing junk? [:'(]
Old 03-26-2007, 10:59 PM
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DMcQuinn
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Default RE: Hobbico Tach Readings Make No Sense

When set to 2-blade setting, it should read 3600 rpm when pointed at a light (in the US where the AC cycle is 60 cycles per second). Mine does this with both flourescent and incandescent lights. I think generally these units are OK, but you may have a bad one.
Old 03-27-2007, 07:02 AM
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RCKen
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Default RE: Hobbico Tach Readings Make No Sense

I would agree that you probably have a bad tach. Call Hobbico (Tower) and let them know that it's not reading properly. Using a flourescant light to calibrate/test it is a pretty bulletproof method. If it doesn't read correctly then something probably wrong with it.

Ken
Old 03-27-2007, 04:07 PM
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Bosch232
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Default RE: Hobbico Tach Readings Make No Sense

Well crap, I don't get it.
I brough it into the house to check it against some older flourescents, and it does indeed read 3600.

There is no way on heaven or earth that a G-45 is turning 13,000 rpm.
Old 03-27-2007, 04:14 PM
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Default RE: Hobbico Tach Readings Make No Sense

You can not use the Tach with flourescemt lighting that is why you are getting bad readings. I know for a fact that my H9 tach says in large type, "Use in daylight only, use under flourescent lighting will give false readings"

Hope this helps you
Old 03-27-2007, 04:27 PM
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Default RE: Hobbico Tach Readings Make No Sense

I had a similar problem when i was running in my saito 125. With a 16.5 x 5 prop i was seeing well over 11k rpms. After replacing the batteries and making sure its still zeroed with a light, i was getting the same reading. With all the fussing i was doing with the tach, and killing valuable daylight i tryed it again. Then I saw normal readings. What actually happened is i was breaking in the motor in direct sunlight, which maybe caused wrong readings due to shadows . So maybe rotate the motor stand more in the shade and see what rpms you get. I bet thats whats going on with you.
Old 03-28-2007, 11:58 AM
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Default RE: Hobbico Tach Readings Make No Sense

RC FUry: I like that wrecked plane pic. I cut the tails off of my yard darts and mount them on a wall. Looks pretty cool....constant reminder of checking your gear out before flying.
Old 03-28-2007, 02:01 PM
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Default RE: Hobbico Tach Readings Make No Sense

I often get false readings with my futaba digital tach when the sun is behind me. The flourescent lite should work with any QUALITY tach.

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