Race Prep on my Crew Hull

[longballlumber]

Alright gang,

As I mentioned in another thread, I wanted to document my steps for preparing my new Crew for club racing this year. This is my attempt to do for you what Darin has done several times for the community here. I am not sure I can do the same justice that Darin does, but I will give it a try.

Nothing new in these first few pictures, but here are some shots of my hull. From the 3 feet (or less) that I was taking pictures, the finish looked good to me. I found it to be acceptable giving the price point of the boat and what you get. I did find what some others would call blemishes, but nothing that bothers me too much. After a day of heat racing, loading, and unloading in the car I am sure that it will get dinged up eventually…

[longballlumber]

Before taking everything off of the boat I did take a picture of motor alignment to the stuffing tube. I would prefer this to be better aligned, but I will address this at a later date when I start putting things back together.

I then proceeded to remove all of the hardware and all of the components. I do this because, to me, it’s easier to work with the bottom of the boat without banging the strut and the rudder. It also keeps the motor clean from debris and dust from sanding. I left the cooling lines that go thru the transom in the hull, because they can be difficult get back thru the transom after they have been removed.

[longballlumber]

In light of stock flex shaft concerns I am going to replace the stock shaft for a Hughey brand flex, but I will be using the stock strut bushing. First thing I did was clean up the end of the stuffing tube (the end were the strut bushing slides into). This isn’t a real big deal, but I sanded the tube end to get rid of any burrs or sharp edges created when it was cut to length. The other quick thing I do is run my Xacto knife (#11 blade) around the inside diameter (ID) of the stuffing tube end. This, again, will get rid of any burrs and put a slight chamfer on the ID making the bushing easier to slide in and out. You can also use the Teflon tubing to aid in this by pushing it from the motor end all the way thru to the strut end. This will help remove any large objects. I also clean out the ID with a Q-tip and make sure no small metal shavings are left over. You might be able to send a Q-Tip all the way thru using a 3/16 flex shaft (no Teflon) as the pushing tool. Again, no rocket science here.

Next is the strut bushing itself, first I clean the outside diameter (OD) of the bushing using some green scotch bright pad. Again this knocks down any burrs and sharp edges left from the machining process. I keep working the OD with the scotch bright until the bushing will SMOOTHLY insert into the stuffing tube and SMOOTHY pull out with no major sticking. After the OD is taking care of I move to the ID. I run a 3/16 drill to remove any burrs or sharp edges, and then Q-Tip to clean. I then slide the bushing onto the stub of the flex and make sure it rotates nicely without any snags. In this case it was like butter. If it did have a problem, I could also take the scotch bright pad to the stub end of the flex. BE CAREFUL, you don’t want to make the stub out of round. As long as you’re using a scotch bright pad and not too much elbow grease you should be ok.

[longballlumber]

For those of you who don't know... Hughey flex cables are the best in the business!

Ed and his brother Dee, were the pioneers of many RC boating inventions/improvements. Many from this board know Ed as a record setting FE boater from the brushed motor days. However, before playing with FE boats he was a very accomplished Nitro racer along with his brother.

[longballlumber]

Next, I moved on to the ride pads. Like ALL boats the ride pads need some attention. As you can see, they were concaved a little. In order to do this correctly you will need a FLAT sanding block and a couple different sanding grits. I started with 120 (I think), but that is only to get things started and the majority of the area flattened out. Once I felt the ride pad was getting close to being completely flat, I switched to 220 to finish up. Couple of notes here; let the sand paper do the work, you don need to “force” the removal of material. It may take you a little longer, but it reduces the possibility of sanding more angle into the ride pad. Remember, YOU ONLY WANT TO MAKE IT FLAT not change the angle.

I found the inside edges to be satisfactory for me. While I won’t say they are “sharp”, they are in pretty good shape. I had originally considered putting new ride pads on the bottom using 1/32 G10 fiberboard. That would really allow me to get edges nice and sharp, but it would require more time and a little more work. After seeing how well the edges were coming out of the mold, I figured it would be OK for now.

This is all I have for now... I will post as I make progress.

Thanks
Mike

[Doby]

For those of you who don't know... Hughey flex cables are the best in the business!

Ed and his brother Dee, were the pioneers of many RC boating inventions/improvements. Many from this board know Ed as a record setting FE boater from the brushed motor days. However, before playing with FE boats he was a very accomplished Nitro racer along with his brother.

Bushings on backwards, 3rd picture

[longballlumber]

Bushings on backwards, 3rd picture

HA.... Also no drive dog installed yet...... It's coming....

I was just checking the fit!

Later,
Mike

[longballlumber]

Alright, I have a few more updates. I’ve done more work here and there, but never found time to get it posted...

Next I started re-installing the motor mount. Instead of using the standard Phillips head wood/sheet metal screws, I replaced them with #4 x ½” button head sheet metal screws (w/socket head). I do this for a few reasons; the first and most important to me is being able to use hex keys for installing and removing, they are used everywhere else on the boat, and hex heads are more resistant to stripping out. The ½” long screws are a little longer than the stock and the major diameter is a little larger and seem to hold better. Even if you don’t change these, keep an eye on them, they will loosen up and start backing out after a few runs. Oh yeah, the button heads will minimize the chance of puncturing any lipos in a crash or flip.

[longballlumber]

Now that I have the motor mount installed, I turned towards the stuffing tube, flex shaft, and coupler alignment.

Recently, I have been replacing the Aquacraft flex couplers with the Octura brand. I feel the Octura’s run a little more true (less run out) for my liking. This is not to say there is something wrong with the stock coupler. As a matter of fact the one I replaced on this boat seemed to be fine. It’s just a personal preference for me, but not a must for everyone.

On a side note, aren't those cooling sleeves nice. I think they are the "cat's meow"

[longballlumber]

As you can see from my first picture, I still have some alignment issues. My objective to get things lined up is so I can insert the flex cable thru the strut and it will push all the way into the collet without moving or tweaking anything. There really isn’t much for me to take pictures off. Once the motor mount was screwed back in, I a little CAREFUL tweaking/bending of the actual mount. I also took out the Teflon tube and inserted a solid rod (as close to the ID of the stuffing tube as possible) and use that as a lever to bend the stuffing tube. Be cautious here, you don’t want to compromise the bond of the stuffing tube in the hull.

You will need to check this often to make sure the motor mount hasn’t been tweaked after running a few times. A misalignment can lead to heat in the stuffing tube.

[longballlumber]

I then moved to the rudder assembly. On the prototype hull that I ran last year, it had a water pickup in the rudder. I actually prefer that set up rather than the brass tubing pickup bolted to the sponson transom. I just so happen to have several spare rudder assemblies so I switched mine out. Oh yeah, something that I forgot to mention earlier when unbolting the hardware. I decided to change out the metric stuff for inch. I went to Lowes and got an 8-32 tap and drill set. It worked awesome. With going to the 8-32 bolts, I needed to clean up the mounting holes on the brackets. I simply used my dremel with a 1/8” carbide cutting bit.

Since removing the current stock setup I had two holes in the sponson transom. I used a 1/8 drill bit and drilled out the existing screw holes. Once the holes are opened up, I used a 1/8” wood dowel, lightly tapped into the hole using some thin super glue to bond it all together. The last steps were to sand flush with the transom and put some epoxy over the wood dowels to protect from the water.

[longballlumber]

More...

[longballlumber]

Once deciding on the different rudder, I disassembled the blade, arm, and hinge. I then immediately reassembled making sure the rudder arm was 90 dgress to the blade and use medium locktite (Blue) for all three set screws. You don’t need a lot of locktite and you want to make sure you don’t get any on the end that touches the shaft you only want it on the threads. A little goes a long way here.

I also started the process of sharpening the rudder. I used a couple different bastard files, then a set of diamond lapping tools, and lastly my dremel with a scotch bright type material to finish it off.

When sharpening the rudder blade try and follow the entire surface of the machined blade. As you can see in my pictures I was removing material along entire machined surface, not just the leading edge. Take your time and try not getting into a hurry. I had more than an hour in sharpening this blade before I was done. I wouldn’t advise using power tools. You can ruin the blade very quickly.

[longballlumber]

The leading edge of the strut got the same treatment...

[longballlumber]

In the spirit of changing my hardware over to inch, I also changed the mounting bolts for the rudder assembly to the bracket. I also replaced the stock shear bolt with a nylon one.