Before everyone reads this section I received an update that Roban has updated their kits to resolve the main gear mounts so the new retracts with the bigger wheels will all fit inside the wheel well. They did this by setting the wooden frames at a slightly higher angle to allow for a full retraction and door closure.
So if you happen to have an earlier kit and also have the new larger wheels with new retracts here's how you can modify your retracts to make the larger wheel fit inside the wheel wells..... Once I got the new retracts from Cliff, my next step was installing them. These guys have identical mountings as the originals so it was just a matter of pulling the old ones out, removing the strut, reinstalling the strut into the new retracts and making sure everything works. As I stated earlier, these new retracts are slower than the originals so need to have some patience.
I also got the new bigger main wheels:
The new wheels are 3 ½ “ while the old ones are 3”. This definitely adds to the scale of the model as the smaller ones just didn’t look right.
Now these larger wheels did result in a problem which is that the larger wheels didn’t let the gear doors close all the way.
Here you can see where the wheel touches the gear door (Yellow arrow) which results in a good size gap on the both ends of the gear doors (red arrows) and where the doors meet.
So somehow I needed to get the retracts to retract further into the wheel well or I needed to modify the gear doors. (If you have the newer kit this issue has been fixed or if you're OK with this small gap you can skip all of the following steps as it won't affect the performance of the plane at all and it may not be that noticeable in the air. I'm sort of a perfectionist so went the route to fix this)
Some of the things I thought about were modifying the wood mounts, heating the gear doors and reshaping them, shimming up the front of the retract mount and also modifying the retract itself.
After looking at the options I felt the best solution was to modify the retract so here’s how I did it.
In this picture I’ve taken apart the retract and you can see where the strut pivot block (Yellow X) hits the case spacer (Red arrow) stopping the pivot block from going down any further.
So my objective was to figure out a way to allow the pivot block to travel just a little bit more.
Here's how I did that:
First disassemble the case.
One important note.. All the bolts have threadlock meaning that they are glued in and meant to stay in! While with the bigger bolts you may be able to torque them off but on the smaller bolts the hex heads "will" get stripped. To resolve this you'll need to heat the bolts to unlock the threads. (Please be careful with this. I have a small pencil torch that I used to head the heads)
First I marked where the case spacer hit the pivot block: (Scribe lines)
Then it was just a matter of filing a notch in-between these scribe lines:
So that was pretty easy but I found I had another problem. Because the pivot block could now travel further this resulted in a gap between the traveling pivot rod (Brass rod, Red arrow) and the pivot block lip (Yellow arrows). (I’m calling these my own names as I have no idea what they are really called)
If this gap was not closed then the pivot block would not rotate as far as I needed it to.
To fix this problem I built up this gap with thicken epoxy.
Here’s a series of pictures showing how I did this.
The tape provides a dam for the epoxy.
Some filing
More filing
You can see how the contour of the epoxy follows the block outline.
This is probably the best picture showing the notch at the top of the pivot block and the build up of epoxy to bridge the gap and how the pivot rod rides under the epoxy lip.
Since there is almost no pressure on this portion of the retract (Where the epoxy buildup is at) I’m not too worried about anything happening to this area.
I finally figured out how to post a video. This explains everything: (You can barely see the notch on the top of the pivoting block and you can also see the epoxy extension.
Next step was to assemble and test it. Everything worked perfectly so I pulled out the retracts again, disassembled everything and then reassembled using Loctite. (Threadlocker)
The last step before installing the retracts into the engine nacelles was to add just a small amount of toe-in on the struts. Not sure everyone will agree on this but it’s worked for me before so I’m a believer. You need to do this before using any Loctite on the retract hold down bolts because on the left side retract you’ll not be able to get to the clamping bolt once you have the retract bolted in.
So I just snugged the strut in the pivot block while the retracts are out, just enough so I could pivot the strut with a little bit of force. Then I bolted the retracts into the engine nacelles, slide a rod through the axle holes and lined these two rods up. Once the rods were lined up then I set about 3* to 5* of toe-in on one side:
Then moved to the other side and set the toe-in on that side. Once this is done the rod tips should line up. This isn’t meant to be perfect as the play in the struts doesn’t allow for any accurate setting but is more just to ball-park the toe-in.
Next step was to take out the retracts, tighten the strut clamping bolt and then remount the retracts back into the engine nacelles with Loctite,
Here's a picture of the gear doors closed after I did the above.
Here's another video of the doors closing:
Next I’m moving back to the fuselage and will work on cleaning up the wiring.
I thought I was going to get the nose retract today but didn’t get this in the mail so looks like I’ll have to wait till Monday. (The last retract, retracted in the wrong direction)