Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

How to install a hobbs/tach?

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Yak-List
View previous topic :: View next topic  
Author Message
1906



Joined: 30 Nov 2018
Posts: 58

PostPosted: Sun Dec 09, 2018 8:11 pm    Post subject: How to install a hobbs/tach? Reply with quote

Is it possible to install some sort oil pressure switch on these?
My mechanic thought he had it, connected to I believe the oil dilution port but it didn't pick up enough pressure for the switch there...


- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
View user's profile Send private message
dsavarese0812(at)bellsout
Guest





PostPosted: Mon Dec 10, 2018 4:08 am    Post subject: How to install a hobbs/tach? Reply with quote

Oil dilution port is an INPUT to the oil pump. Not an OUTPUT. Find the oil pressure line coming the oil pump and going to the triple instrument in the cockpit. It is a flexible hose.
Dennis

Sent from my iPad

Quote:
On Dec 9, 2018, at 11:11 PM, 1906 <zmadwolf(at)gmail.com> wrote:



Is it possible to install some sort oil pressure switch on these?
My mechanic thought he had it, connected to I believe the oil dilution port but it didn't pick up enough pressure for the switch there...




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=486201#486201











- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
Looigi



Joined: 20 Apr 2015
Posts: 80
Location: Christchurch, New Zealand

PostPosted: Mon Dec 10, 2018 11:21 am    Post subject: Re: How to install a hobbs/tach? Reply with quote

Can I ask a stupid question..... Why would you want to?

My Yak is in a syndicate of 9 people, so we need to track flying time so Rob can send each of us his monthly hate mail.... the bill.

Given that the Yak needs a lot of time to get the engine oil up to temperature, especially in winter, I didn't want to use an oil pressure switch. I needed to record flight time, not engine time because I didn't want guys to try and save themselves a few cents by short cutting the warm up only to cost us big bucks on engines.

I installed a Hobbs and a pressure switch. The Hobbs has its own power supply, through a circuit breaker straight from the master switch and is turned on by a small pressure switch plumbed into the pitot system. There was a convenient unused pipe behind the back seat where some sort of "flight data recorder" once was, and I just plugged into that. When we were doing the bi-annual pitot test, I adjusted the switch to come on at about 60km/h airspeed.

If this sounds a solution to your problem, I can dig out the details of the switch I used.

I hope this helps,
Chris


- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
View user's profile Send private message Visit poster's website
cjpilot710(at)aol.com
Guest





PostPosted: Mon Dec 10, 2018 1:37 pm    Post subject: How to install a hobbs/tach? Reply with quote

At the Collings Foundation, the B-24 Hobbs was hooked up to the landing gear strut. With strut extended a switch powered the Hobbs meter. The FAA seems to be happy with that. Jim "Pappy" Goolsby


--


- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
wlannon(at)shaw.ca
Guest





PostPosted: Mon Dec 10, 2018 7:44 pm    Post subject: How to install a hobbs/tach? Reply with quote

Looigi;

While I have no concern with your choice for activating the Hobbs meter I do
have a problem with your choice of power supply.

The battery master switch is there to activate the battery master relay
which in turn powers the bus. None of the bus load is carried through the
switch which is sized for it's primary purpose only. The load you are
adding may not be enough to cause a problem but I believe you are breaking a
cardinal rule in aircraft electrical practice.
Since operation of the entire electrical system depends on the master relay
the loss of it's power supply (the switch) means total elec. failure. Any
added elec. load should always be taken directly from the bus never from the
master switch.

Walt

--


- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
Looigi



Joined: 20 Apr 2015
Posts: 80
Location: Christchurch, New Zealand

PostPosted: Tue Dec 11, 2018 12:08 am    Post subject: Re: How to install a hobbs/tach? Reply with quote

Hi Walt,

Yep, I considered that. Admittedly I am an engines and airframe man and I much prefer working on bits I can hit with a hammer.

In my defence though..

The switch is very typically Russian and over rated to the max. From memory, it has 10A marked on it, but don't quote me on that.

The Hobbs I am using has a 0.8mA draw at 12vdc (so 0.4mA at 24v) and the CB is mounted only a few inches away from the switch. I can't remember the rating of the CB, but it was the smallest I could get.

Chris


- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
View user's profile Send private message Visit poster's website
1906



Joined: 30 Nov 2018
Posts: 58

PostPosted: Tue Dec 11, 2018 7:48 pm    Post subject: Re: How to install a hobbs/tach? Reply with quote

I appreciate your input guys. My hobbs was connected to the engine instruments switch and any time I do some maintenance or troubleshooting, the thing just keeps adding time. How do you accurately maintain the actual time on the airplane for maintenance and resale purposes otherwise? That was my reasoning.

- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
View user's profile Send private message
Viperdoc



Joined: 19 Apr 2014
Posts: 484
Location: 08A

PostPosted: Tue Dec 11, 2018 8:13 pm    Post subject: How to install a hobbs/tach? Reply with quote

The aircraft originally did not have a Hobbs. The flight time was recorded in the a/c log books. Mine does not have a Hobbs. I keep up with flight time with a separate column in my log books.
Doc

Sent from my iPad

Quote:
On Dec 11, 2018, at 9:48 PM, 1906 <zmadwolf(at)gmail.com> wrote:



I appreciate your input guys. My hobbs was connected to the engine instruments switch and any time I do some maintenance or troubleshooting, the thing just keeps adding time. How do you accurately maintain the actual time on the airplane for maintenance and resale purposes otherwise? That was my reasoning.




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=486248#486248











- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List

_________________
Viperdoc
Back to top
View user's profile Send private message
n13472(at)aol.com
Guest





PostPosted: Tue Dec 11, 2018 8:26 pm    Post subject: How to install a hobbs/tach? Reply with quote

Hook it to one of the landing gear up lights. This way it is recording
flight time only.
unless you like to fly with the gear down?
Tom Elliott
CJ-6A NX63727
777 Quartz Ave
PMB 7004
Sandy Valley NV.
89019
Cell 541-297-5497
N13472(at)AOL.COM
--


- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
jbsoar(at)gmail.com
Guest





PostPosted: Tue Dec 11, 2018 11:00 pm    Post subject: How to install a hobbs/tach? Reply with quote

There is a really good digital tachometer available that also counts engine hours.  Contact me off the forum for specifics.

On Tue, Dec 11, 2018 at 9:55 PM 1906 <zmadwolf(at)gmail.com (zmadwolf(at)gmail.com)> wrote:

Quote:
--> Yak-List message posted by: "1906" <zmadwolf(at)gmail.com (zmadwolf(at)gmail.com)>

I appreciate your input guys. My hobbs was connected to the engine instruments switch and any time I do some maintenance or troubleshooting, the thing just keeps adding time. How do you accurately maintain the actual time on the airplane for maintenance and resale purposes otherwise? That was my reasoning.




Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=486248#486248






===========
br> fts!)
r> > e.com" rel="noreferrer" target="_blank">www.mypilotstore.com
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
          -Matt Dralle, List Admin.
===========
List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?Yak-List
===========
FORUMS -
eferrer" target="_blank">http://forums.matronics.com
===========
WIKI -
errer" target="_blank">http://wiki.matronics.com
===========
b Site -
          -Matt Dralle, List Admin.
rel="noreferrer" target="_blank">http://www.matronics.com/contribution
===========





- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
cjpilot710(at)aol.com
Guest





PostPosted: Sun Dec 16, 2018 2:19 pm    Post subject: How to install a hobbs/tach? Reply with quote

The airlines don't really keep track of "Flight time" as much as they do "cycles". Some of PAAs 747SP would be airborne as much as 20 hours per day but with just 2 cycles (1 takeoff 1 landing). Replacement of things like landing gear was based on cycles. I use the time off my electronic tach (engine running). The B-24 I flew for the Collings foundation use the "squat switch" on the left landing gear to run a hobbs meter. I personally don't remember anywhere in the regs (AND I CAN BE WRONG) where it says HOW the time would be determined for light aircraft. It seems to me a timed cycle (ala gear switch) or engine running (electronic tach or oil pressure Hobbs) would be close enough.
Jim "Pappy" Goolsby

--


- The Matronics Yak-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Yak-List
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Yak-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group