Rear Mixture cable

Gord Tessier · #1 06-07-18, 12:17 PM

Hi Folks, my rear mixture cable starting to get a little hard to move and there is deficitely some binding going on in the cable. Saw the old posts. Mine is a G model.

Do we have a preferred vendor for these?

kilr4d · #2 06-07-18, 03:34 PM

Gord,

I believe that the right answer will be Don Neisser:

Don Nieser
Commodore Aerospace Corp
6221 Commodore Lane
Oklahoma City OK 73162
405-503-4686
niesser.02.337parts@juno.com

I know another Canadian 337G owner just replaced his flap indicator cable and Don was the guy to buy it from.

cessnadriver · #3 06-07-18, 05:18 PM

Kilr4d.
You can get it from McFarlane Aviation. BUT I think you have to send the old one to them so they can match it. Their cables are FAA/PMA you'll have to have a FAA Form 337. Not sure about Air Canada (Your counterparts to our FAA) requirements but I think they go along with FAA requirements. The McFarlane SHOULD be cheaper than Don but his parts are Cessna parts no Form 337 required IF he has one. Hope this helps.
Regards, BILLS

hharney · #4 06-08-18, 03:13 PM

McFarlane has really good control cables. In fact the owner has a Skymaster and has been on this forum. I had some issues with the cables they made for me and they chose not to remedy the issue and therefore I had to send them back and they credited me for the charges. The unfortunate part of the situation is that I had to buy Cessna brand instead and they are not as good as the McFarlane cables. I tried Don but his are military issued and would not work on my C model. It's not a fun task to change these cables out so if you are changing one my suggestion would be change all three at the same time. If you can get the McFarlane to work for you that would be best. Good luck

Kim Geyer · #5 06-09-18, 11:42 AM

McFarland cables are very good and cheaper than Cessna. The one problem I had with them is the internal travel limits. The prop and mixture cables were ok but would run out of travel with the throttle

kilr4d · #6 06-11-18, 02:29 PM

Quote:

Originally Posted by Don Nieser

This is an update to my 2011 post.
I now have new Cessna surplus front engine control cables for prop, mixture and throttle and New Cessna rear engine control cables. My prices are always less than anyone else and you can return anything you get from us without question.
I recommend that during installation of these cables that you add fire sleeve material around the cables where they are close to the exhaust pipes to prevent the coating from being burned off.
Call or e-mail me for all your 337 and 0-2 parts and equipment, Don Nieser, nieser.02.337parts@juno.com, Commodore Aerospace Corp, 405-503-4686

Just adding this quote from the other thread...

kilr4d · #7 06-11-18, 02:29 PM

Quote:

Originally Posted by Kim Geyer

McFarland cables are very good and cheaper than Cessna. The one problem I had with them is the internal travel limits. The prop and mixture cables were ok but would run out of travel with the throttle

Isn't "very good" and "run out of travel" sort of at cross purposes?

Gord Tessier · #8 06-17-18, 09:58 PM

Quote:

Originally Posted by Gord Tessier

Hi Folks, my rear mixture cable starting to get a little hard to move and there is deficitely some binding going on in the cable. Saw the old posts. Mine is a G model.

Do we have a preferred vendor for these?

'
Thanks for all the replies!

DaveM · #9 08-31-18, 09:13 PM

A little about the engine control fit issue. The reason a lot of the engine controls on the Skymaster get stiff to work is that the original control conduit are made with long lay conduit (many wires twisted in a slow spiral) or a square flattened wire conduit with a armored inner wire. They work well when new, but when they age from many heating and cooling cycles the outer conduit wire stress slowly collapses the inner plastic liner onto the inner wire. This only happens in the control bends. The results of many bends is a lot of friction in overall control operation. The McFarlane controls have a conduit that is made of a two wire conduit with a relatively short lay (tighter spiral). The inner conduit size will not change in the bends as it ages and as a result it will not get hard to work as it ages, but the bend clearance presents its own set of issues.

Ok lets talk about travel problems. As a push pull control is makes a bend, there is a difference between the radius of the outer conduit and the radius of the inner push-pull wire. This difference effects the travel available in the control assembly. When the side clearance of the inner wire in the conduit is greater the difference of the two radii also increases. This difference also increases the effect on overall control travel available. In summary the more free fit you have in the conduit bends the greater the loss of travel. This travel loss is accumulated in proportion to the number of bends and the degree of the bends. When building a control without the airplane, it is very hard to predict the control bends used in the routing. The advantage of the original long lay conduit is that the inside hole of the conduit gets smaller in the bends. This restriction of the conduit inner hole size in the bends limits the loss of travel caused by bending the control. The number of bends in the control routing have only a small effect on the amount of travel available making this type conduit easier designer friendly. With the McFarlane control, some travel is lost in each bend do to inner wire free running side clearance. (This is what gives us our ageless smooth operation). This loss of travel must be compensated for by adding inner wire length. The amount to add depends on the number of bends and the degree of bends in the routing. We have gotten better at estimating the amount of travel compensation to give the 337 controls, but there are different routings for the different models and the routing has been modified on some airplanes. If we give to much compensation for bend loss, we run the danger of improper overlap of the telescoping control ends and the push rods being to long to fit in the space allowed. The problem is exacerbated by the sheer length of the rear engine controls and many bends required. We collect data for each one we build to try and perfect the fits but it is a continuing challenge due to model and airplane variations. It is an engineering challenge with some trial and error learning. McFarlane can not simply match the original and make it work, but we have perfected it for many models. We recommend that you measure the travel used by your working control on the airplane before you remove it. Before you install a McFarlane control, simulate the routing bends required (it might take several people) and then check to see that there is enough travel available. If the travel does not match the old control, return the control and we will re-make it with a different travel allowance. It is important that all bends are simulated. This process will prevent the hours of labor required to uninstall the control assembly.

n86121 · #10 09-09-18, 01:49 PM

Years ago I went with the McFarlane, and the bill was something like 11 hours labor from a very reliable shop I had used for years.

Another mechanic scoffed at that, and did them on someone elses c337.

14 hours.

Just a pain aux derriere, so be prepared.

JAG · #11 09-09-18, 05:32 PM

DaveM - which models have you perfected the controls for - do you mean certain C337 models like A, D and G, or do you mean other aircraft models like C182, etc. If I am going to change a rear engine cable, I would much rather go with a new design that will outlast me.
Thanks,
Jeff

DaveM · #12 09-09-18, 10:12 PM

Many letter model of the Skymaster are a little different. I am referencing Skymaster models. The guys in the McFarlane control shop will have more specifics.

spurlockda · #13 09-27-18, 11:47 PM

Speaking of control cables, I think I am having a problem with them of a different sort.

I believe that in some point in the past, maintenance performed for the owner(s) resulted in the cables being ??re-installed?? Unfortunately, it seems like they were not re-installed in the right locations. Possibly routed incorrectly but one has a huge bow where the cable exits from the tunnel in the aft wheel well and before it goes up through the shelf into the aft engine compartment. In addition, the aft prop and throttle levers have restricted travel at the end of their throws. One way I think I can tell they have been messed with is that they are interleaved in the hyd lines aft of the under-floor pressure bulkhead.

I haven’t been able to find anywhere that explains which control cable goes where between the levers and the engine.

Can anyone steer me in the right direction?

Thanks,
Dave

hharney · #14 09-28-18, 09:27 PM

Have you tried to pressure lube them? This can be a temporary fix until you have time to pull them out and replace them.

spurlockda · #15 09-28-18, 10:40 PM

Thanks Herb for your post.

Actually, now is an opportune time to work on repositioning the cables if in fact they are mis-rigged. I have everything pretty much disassembled because I am - well the plane is - going through an major avionics upgrade and we discovered that the wiring was pretty brittle and had been messed with like the control cables were.

I want to put everything back together right so I’m trying to figure out where to find the ‘right’ answers. I know you are one of those guys with the right answers.

V/r,
Dave