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Technical Innovations 15 ft Home Dome problems

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#1 lhf14

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Posted 17 February 2013 - 03:47 AM

I purchased this dome thinking that it would be the best buy for the price in the range of 4-4.5m domes. Although it is now working, there was a great deal of difficulty in assembling it due to wrong instructions in the manual, instructions that were unclear of just didn't make sense, and obsolete instructions which must have come from other versions of the manual. However two problems occured after assembly and one hopefully may be cured by suggestions by forum members. The first problem was that the shutter did not ride over a correct hemispherical ridge, which is required for the three shutter sections to properly interleave during opening. Eventually I had to install stainless steel guides to lift the front section so that it wouldn't hit the top section (which prevented interleaving). I can happily send photos to anyone interested in pursuing this fix. The second problem is the terrible very loud noise generated by the pair of shutter motors sent by TI. They sound like a dying banshee and cause the neighbours to complain. One neighbor across the street measured 76dB in his bedroom when I was closing the shutter at 2am. This sound level of course is forbidden by local bylaws, so I would dearly like to hear from anyone who has been able to solve the problem. I notice that one MAPUG forum TI dome owner mentioned that the motor covers for the dome azimuth motors didn't work to reduce noise from his motors and nothing is sold by TI for excessively loud shutter motors. Please help if you have any good ideas!

#2 dobsoscope

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Posted 17 February 2013 - 04:32 AM

76dB across the street! I wonder what the levels is inside the observatory itself! If it exceeds 80/85dB it will cause you permanent hearing damage... WHO docs refer.

#3 Christopher Erickson

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Posted 17 February 2013 - 04:45 AM

Just one of the long list of reasons why I don't like TI products!

First step is to figure out exactly what spot is creating the loud noise.

Sometimes Teflon sheets can be used to resolve a small, high-friction point.

Another possibility might be to add a PCM-based motor speed control to slow the motor down a bit and hopefully avoid the resonating threshold.

And Superlube can help some metal-on-metal noise sources.

Can you capture a video (with sound) of the problem and send it to me off-forum (christopher.k.erickson "at" ieee.org) for review?

#4 kiwisailor

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Posted 17 February 2013 - 04:52 AM

You could try Potters for some Barium loaded insulation foam, this is commonly used in Marine construction to isolate engine noise from everywhere else on board

Sorberflex is the trade name and there are a variety of diffent types- Soberflex

I used it to line plastic granulators gobbling up plastic waste, I've no doubt that it will tame your noisy motor- can't have the neighbour dobbing you in to the local council's noise control officer, can we.

Welcome to CN and the Observatory threads too Laurence

#5 JAT Observatory

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Posted 17 February 2013 - 10:25 AM

I'm trying to understand why a motor would be that loud! Is it actually the motor or the shutters? My dome's bottom shutter is a screw drive and it's pretty quiet as is my flat gear driven top (up and over) shutter. The problem I have is when it gets hot in the summer sometimes the fiberglass will squeal where it rubs some of the rubber rollers that don't always roll. Some well placed spray lube cures that.

#6 s800

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Posted 19 February 2013 - 12:28 AM

Are the motors in question the funny-looking "teardrop" gearbox/small DC motor combo?

If so, these are very loud. I've swapped mine out and it has made the dome whisper quiet. I thought TI wasn't shipping these old motors any more but ICBW.

#7 lhf14

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Posted 07 March 2013 - 03:13 AM

Hi Ryan:

thanks for your reply to my Home Dome problem with the loud shutter drive. If you have swapped out those horrible motors/reduction boxes, then what did you substitute them with? I was told by TI that they had problems with a weak assembly initially and had to go to the more grunty reduction box. Perhaps that is only needed for the 15ft dome???

Am most interested to know what is your replacement drive assembly!

#8 lhf14

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Posted 07 March 2013 - 03:18 AM

I'd like to thank all you guys for your helpful comments on the 15ft HomeDome shutter problems. And thanks Steve H in Lyttleton for the lead to Soberflex. Hopefully, with Chris Erickson's help I can knock the screaming shutter assembly on the head.

Larry

#9 Startraffic

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Posted 11 March 2013 - 07:18 AM

lhf14,
Not to sound dumb, but have you contacted TI? They are literally 2-3 miles away from me, & were extremely helpful when I stopped in unannounced to pick their brains about a used PD that I was looking at & didn't buy. Give them a shout on their website. They probably have had the kind of problem & will have some solutions for you.

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#10 Aquarist

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Posted 12 March 2013 - 08:06 AM

As a reference point, TI pretty much kept to the schedule initially promised (15 foot). And so far, at least, they have been very responsive to questions.






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