Mon Jul 14, 2008

 I lowered the engine into place and installed the thrust prop idler tensioners.

I also positioned the lift belt and started installation of the lift belt idlers.

Mon Jul 14, 2008

Cont...

Tue Jul 15, 2008

Installing engine starter key harness and choke cables to dash

Installing control system pulleys

Mon Jul 21, 2008

I got the engine back in the craft and everything assembled.  I fired it up and my belts weren't correctly tensioned and the belt jumped off the mid idler.  Also the thrust prop was badly out of balance which made the craft vibrate and shake more than it should.   I tried to take the craft out in the grass field by my house but I just couldn't get it going in the grass.  The field has a pretty uneven dirt base. 

At this point I have 3 issues:

1 - Out of balance Thrust Prop (probably lift fan too)

2 - Mid idlers jump belt.  Need belt keeper.

3 - Bike hand brake thrust control not enough movement to activate full throttle on motor.

I am in the process of balancing the Thrust Prop.  I am using the jig in one of the pictures in the right to balance the prop.  Basically a couple of saw horses with angled 3/4" aluminum on the top and all leveled out.  One blade was a lot lighter than the other.  I gave the blade a complete coat with epoxy and it is getting better but still lighter.  Next coat will be with paint and I should be able to get it in balance.

As for the Mid Idlers I built some belt keepers and they seem to work fine.  They are pictured right.

Now the hand brake thrust control.  I haven't fixed this yet.  I have a couple of ideas but haven't figured out what I am going to do to fix this.

Mon Jul 21, 2008

Cont...

Update: I got the thrust prop balanced tonight.  After I coated the lighter blade with paint it needed a small amount of paint on the other blade to keep it in balance.  Hopefully my vibration will be minimized.

I still need to balance the lift prop and figure out a way to fix my throttle cable throw issue.

Wed Jul 23, 2008

I was able to adjust the cable on the throttle to get full rpm on the engine. 

Second video after some tweaking.  Tightened the thrust belt a little more and adjusted the throttle cable so I could get full rpm.

To do: Duct guards, Windshield

Wed Jul 23, 2008

Cont...

The lift belt would occasionally hit my elevator cable at certain RPM's.  I built a touch bar to prevent it from touching the cable.

Wed Jul 23, 2008

Cont...

Second Flight - Video

Third video shows belt flop at lower rpm's...trying to get to the bottom of some vibration issues.  Some details on where I am at...

> Hi Ken,
>
> I took the props off again and ran the craft.  The vibration only occurs at
> certain rpm ranges.  I was watching the lift belt at the back (with prop anf
> fan off) and at a lower rpm I noticed some vibration.  The lift belt was
> flapping a fair amount between my mid range idlers and the engine pulley.
> Once I increased the RPM and got the flap to minimize the vibration did as
> well.  The vibration may be caused by the lift belt flapping at certain rpm
> ranges (usually lower end).
>
> The balance shaft is keyed and appears straight but I will test as you
> describe.  My balancing rig is two sawhorses with 3/4" aluminum angle taped
> tight to the top of each sawhorse (36" wide) so the sharp angle is up.  I
> then use a level to get each saw horse level and level with respect to each
> other.  I took my prop and mounted it to the balancing shaft using the
> mounting hub and bushing from the craft.  I found the heavy blade (was very
> obvious as it always went to the bottom fast).  I turned the prop around on
> the saw horses to double check.  I also removed the prop from the balancing
> shaft and turned it around on the shaft and tried again and confirmed the
> heavy blade.  I don't think its the best rig for balancing but I think I got
> it pretty close to being balanced.  When I was done I could balance the
> blade in the center and about 30 degrees down on either side without it
> trying to tip the other way.
>
> As for the exhaust I need to get a small pipe to slightly redirect it as it
> is hitting the bottom of the cockpit side.  It's what's making that weird
> sound.  I'll get the pipe tomorrow.  It could be contributing a little bit
> as well.
>
> It's only certain RPM ranges that I am getting the vibration in (or the
> vibration is more pronounced in)  which is making me think that the lift
> belt flapping might be the cause of some of it.  I'll pay closer attention
> next time I get the props on.  The vibration is really only noticeable at
> the top of the duct at the trim wing mounts and transfers some of the
> vibration into the rudders.  The rest of the craft doesn't seem to have an
> issue.  The lift fan was nice and smooth in my two short hover flights
> (video on my site)
>
> I like that balancer you linked.  I'll probably end up buying one.
>
> I checked my prop shaft pulley and it does not appear to wobble and appears
> true.  I used the (can't remember the name of the instrument) to measure
> both and they seemed fine.  The lift belt is flapping though I've got some
> video and I'll post it on my site shortly.  I just noticed what sounded like
> a bearing noise when I throttled up coming from one of the thrust prop
> pillow block bearings.  Hopefully the sound will come through in the video.
> They have grease nipples on them and I gave them grease back 6 or 7 years
> ago but none since...they have'nt been used really though since then.
>
> I just checked my pulleys and they are right on the money.  I was able to
> hold a ruler almost touching them.  They are on center and also no wobble.
>
> As for your last comment about the exhaust noise.  Yes it does sound weird
> it's because like I said above the exhaust is hitting the inside of the
> cockpit slighlty and needs to be redirected.  The weird sound goes away when
> I redirect the exhaust by holding a piece of plywood at a slight angle to
> deflect it away from hitting the inside cockpit wall.
>
> Thanks for all your tips.  Very helpful.  I'll get this thing beat soon I
> hope.
>
> Brendin
>
 

Thu Jul 24, 2008

The video shows the new sound the craft makes.

Fri Jul 25, 2008

Sat Jul 26, 2008

Seems to work well so far.  I haven't  tried loading it on the trailer yet.

Position the dolly under the craft near the center of gravity and you can lift the nose easily.  I do it with one finger in the picture right.