Skymaster F14 Tomcat
03-29-2016, 06:07 PM
#1576
So I finally got around to to checking a couple things on my tomcat and I am curious about what has caused four of these to crash here in the states or at least that is what was reported on here? We all know what happened when only one crashed from another brand, not to start a huge flaming war but has anyone that has crashed one identified the problems and sent this to SM? I know from him posting one went down to possible servo arm bending but what about the others? I only ask because the only thing really holding me back from flying mine is the unknown. So just to help others out I also wanted to give some new mods I am going to recommend if anyone ask me. The first is to check your rudder mount bracket bolts, they may appear tight but check after the first flight because its a thin soft ply used for this bulkhead. Second, the servo boxes for the stabs, it is made of the same soft ply which is doubled up to make about a 1/4 in thick, it is soft and the screws just dont hold, I wish sm would stop using the this stuff except for equipment trays. Lastly, dont use the stock rudder servo rods unless you run a carbon tube over them. I welcome any ideas or thoughts about my mods or to the above comment, im not trying to start a big argument I just want a safe model that I don't have to worry about hurting someone. Thanks up front
03-29-2016, 07:50 PM
#1578
You had a failure which led to the end result, if this was your fault okay but you posted the arm bent causing slop that caused flutter. The resulting bad landing was due to the stab not working correctly was it not?
03-29-2016, 08:43 PM
#1580
Barry explained why his crashed. Says a lot that he still had control. EDFJim has posted a solve for that. From what I've been told, another went down because of a build error on the rudder linkage. I haven't heard about the other two crashes. Regardless, this plane is leaps and bounds better designed than that other brand. Mine will be here soon and I look forward to flying it.
03-30-2016, 05:21 AM
#1583
03-30-2016, 05:22 AM
#1584
Aside from the crash due to the rudder linkage setup, what are the other crashes?
Last edited by dubd; 03-30-2016 at 05:28 AM.
03-30-2016, 05:46 AM
#1586
I think Jim has proved how durable this plane is with how he cranks and yanks on it. Hell he even flew it through a tree top at my home field and had it flying the next day.
hope you post some pics when it arrives!
03-30-2016, 07:01 AM
#1589
When I was looking at the one that went in at TopGun last year it had tons of slop on the rudder hinge pin along with the bad servo connection. I checked the other F14 that was their and it also had allot of play on the rudders at the hinge pin. More then I would feel comfortable flying with. Keep in mind these where very early F14s and probably have changed since then.
I think Jim has proved how durable this plane is with how he cranks and yanks on it. Hell he even flew it through a tree top at my home field and had it flying the next day.
I think Jim has proved how durable this plane is with how he cranks and yanks on it. Hell he even flew it through a tree top at my home field and had it flying the next day.
03-30-2016, 07:04 AM
#1590
In the interest of providing accurate information, please state what happened with the other crashes in the US. You mentioned a total of 4 and we know what happened with 2. The more we know, the better the chances of each of us having success with this model.
Last edited by dubd; 03-30-2016 at 07:17 AM.
03-30-2016, 07:31 AM
#1591
This was my intent, just trying to save myself and others to come the heart ache. I love the jet and I would like to show it off at events, I would hate to lose it or worse hurt someone because I didn't ask a question.
03-30-2016, 08:06 AM
#1592
My Feedback: (2)
Join Date: Oct 2004
Location: Durham, NC
Posts: 334
Likes: 0
Received 0 Likes
on
0 Posts
hey hey let's forget about the tree .. that thing jumped up and attacked me. There are two sizes of piano wire in this model the smaller wire is for the wing hatches the larger wire is on the rudder and flaps. one of my rudders came with the small size wire ( causing slop) from the factory and I had to change it.
03-30-2016, 08:35 AM
#1593
My Feedback: (2)
Join Date: Oct 2004
Location: Durham, NC
Posts: 334
Likes: 0
Received 0 Likes
on
0 Posts
there are two weak points in the flaps. The steel rod that has a 45 bend in it is very strong and has a flat in it to fit into the aluminum hub that bolts to the servo disk. the flat has a M4 set screw. the flat part of the aluminum hub is starting to open up and distort letting the steel shaft twist causing slop. SM should put out a stronger steel hub for a fix. second weak point are the plates in the flap that the store shaft moves in. groves form in the fiberglass plates from the steel rod causing slop in the flaps up position. a thin steel U channel at the up position would be a good fix .. I'm working on that now and will post pics in a few weeks.
03-30-2016, 08:36 AM
#1594
hey hey let's forget about the tree .. that thing jumped up and attacked me. There are two sizes of piano wire in this model the smaller wire is for the wing hatches the larger wire is on the rudder and flaps. one of my rudders came with the small size wire ( causing slop) from the factory and I had to change it.
03-30-2016, 08:48 AM
#1595
My Feedback: (2)
Join Date: Oct 2004
Location: Durham, NC
Posts: 334
Likes: 0
Received 0 Likes
on
0 Posts
main gear need high pressure 120 psi to retract and have the strut compressed and released to have fluid moved around to lube the internal rotating parts . gear needs to extend slow or it will be damaged when it slams down. I use 1 jetronic valve for each main with the throttle function used with 6 second time for extension and 1 sec for retraction . also need air pressure on the mains to stay extended or they will fold on the ground( I made gear locks when my power is off).
03-30-2016, 08:51 AM
#1596
My Feedback: (2)
Join Date: Oct 2004
Location: Durham, NC
Posts: 334
Likes: 0
Received 0 Likes
on
0 Posts
Tree? your not talking about your current tomcat are you? I did check this, the wire for my rudders and flaps is thicker than the top hatch wires. I added hysol to the horns and let it set awhile then pushed the rod through to give it that nice fit. I may try getting a larger wire, the wire size FB uses would be perfect for these larger models. Jim you going to MS jets?
03-30-2016, 09:03 AM
#1597
The gear on mine has been a big issue as well, did SM send you the updated air lock cylinders? If so do you still need to slow the gear coming down? With my mechanical valves not sure how to slow down one side unless I can put some type of servo travel slow on one direction. Danny Diaz made a stop bracket for his I thought about trying that method. I have two valves for the mains with both feeding the nose.
03-30-2016, 03:57 PM
#1598
main gear need high pressure 120 psi to retract and have the strut compressed and released to have fluid moved around to lube the internal rotating parts . gear needs to extend slow or it will be damaged when it slams down. I use 1 jetronic valve for each main with the throttle function used with 6 second time for extension and 1 sec for retraction . also need air pressure on the mains to stay extended or they will fold on the ground( I made gear locks when my power is off).
I bought Danny's F-14 and have been trying to figure out what the best way to fix the retract issue would be since it's got a bit of a problem with the left main getting all the way retracted. He told me it was fixed but even sitting on the bench it doesn't want to play so with an air load it'll be worse. I've not tried going to 120psi yet, I may go do that before I start tearing stuff apart other than what I need to get the water out of the systems....
My builder guys changed out the Jetronic valve on the retracts to a mechanical so it'll leave air pressure on the gear when they put the new engines in it, but I'll need to build some little blocks as a just in case/out of air deal for the gear. That also will leave me the option of slowing down the servo that operates the gear valve on the extension side of the operation. Now I've not explored the idea of slowing the servo down in one direction, but if this 18MZ can't do it I don't know what would. Keith, if you figure that one out, how about letting me know??
Last edited by Zeeb; 03-30-2016 at 04:03 PM.