old heading indicator (jammed resetting screw)

[seventy]

Any idea on how to loosen the resetting screw used to adjust the (1952, 170B) heading indicator with the compass?

[DaveF]

Not familiar with that instrument, but what problem are you having? Can't loosen the set screw? There isn't a set screw?

[GAHorn]

Any idea on how to loosen the resetting screw used to adjust the (1952, 170B) heading indicator with the compass?

These airplanes can have any number of “heading indicators” installed. Which specific instrument (brand, model, or other identification/picture) can you provide?

[seventy]

DG from Jack&Heintz Co., Bedford Ohio
AN-57351
if you want to see pictures, I suggest you visit https://flyingcolorsairparts.com/22180

As a new member, I have found out how to attach a picture.

[gfeher]

Seventy, from the photo at the link you posted, I'm assuming that you are referring to the adjustment knob below the window that you use to set the DG. When I bought my 170 years ago, I had the same problem. I couldn't set the DG because the knob wouldn't turn. When I was at Keystone Instruments in PA dropping off another instrument, I asked them about it. They said that the knob needs to be lubricated periodically and that I should spray a light lubricant in where the shaft of the knob comes out of the body and slowly work it loose. Then regularly lubricate it, at least annually. I used Corrosion X in mine, which not only is a good corrosion inhibitor, but is a good light lubricant. It worked like a charm. Mine loosened right up. If that doesn't work, then you may have a more serious problem with it.

BTW, if you are not familiar with this DG, you need to pull the knob out before you can turn it. So first work the knob out before attempting to turn it. Edit: See the correction to how the knob works in the next two posts below. Brain freeze on my part. Push in and rotate the knob to adjust the DG, pull out to return to DG mode. Point being though, you need to be able to move the knob in/out as well as to rotate it.

[seventy]

Thanks Gene,
That's exactly the adjustment knob you are describing. I have tried "Moovit" from Lloyds Laboratories. It works fine to lubricate doorlocks and carlocks. It always prevent freezing of carlocks due to freezing rain. However, so far, it does not work with the DG. Will try to have access to "Corrosion X".

[GAHorn]

Seventy, from the photo at the link you posted, I'm assuming that you are referring to the adjustment knob below the window that you use to set the DG. When I bought my 170 years ago, I had the same problem. I couldn't set the DG because the knob wouldn't turn. When I was at Keystone Instruments in PA dropping off another instrument, I asked them about it. They said that the knob needs to be lubricated periodically and that I should spray a light lubricant in where the shaft of the knob comes out of the body and slowly work it loose. Then regularly lubricate it, at least annually. I used Corrosion X in mine, which not only is a good corrosion inhibitor, but is a good light lubricant. It worked like a charm. Mine loosened right up. If that doesn't work, then you may have a more serious problem with it.

BTW, if you are not familiar with this DG, you need to pull the knob out before you can turn it. So first work the knob out before attempting to turn it.

Errr… Gene… MY AN-DG …requires that I PUSH IN the knob to make any adjustments..then when the proper adjustment is complet…Pull Out to return it to DG mode.

[gfeher]

Geeze, George, you are right. So does mine. Brain freeze on my part. I quickly jotted what I wrote down without stoping to think about it for a second. Sorry for the misinformation Seventy. George is right. Push in to adjust, pull out to return to DG mode.

[GAHorn]

Seventy, …here is a pic of the AN-type of D.G. We are discussing. This is the type you are asking about, correct…??

BTW, the link you offered to buy a “used” Jack and Heintz for $25… is not a purchase I’d recommend. They are offering it for “parts”… but no one will overhaul a J&H gyro…so purchasing it for “parts” is pretty useless. If you have almost ANY OTHER make of “AN” gyro…(such as a Sperry, Tennstedt/G.M., etc. it can likely be overhauled by Aircraft Quality Inst’s in Wichita. https://www.flyaqi.com/

[seventy]

This is exactly the AN type of DG. Will see what comes next. Thanks for your advice about "useless buy or repair".