Mon Aug 27, 2001

3.5 hours

This evening I continued working on the skirt.. I have it mostly attached to the hull.

Pictured top right - Marked a t square line every 3 feet to 9 feet starting from the rear of the craft onto the skirt.

Pictured 2nd right - marked the same lines onto the hull using the tsquare.  The lines are tangent to the curvature of the hull.

Pictured 3rd right - One inner tack strip screwed.  I pre-drilled the hole before I put in the #8 x 1/2" fat head pan screw by hand.  Note the screw spacing typical 4" but I spaced 2" across the lift duct splitter to seal it better.

Pictured 4th right - The other side screwed.  Note the frequency of screws over the lift duct splitter.

Pictured 5th right - The rear inner skirt attach.  Instead of putting the screws on the outside of the bag like I did on the inner tack strips I put it on the inside.  It just seamed to naturally fit better.  Downside I can't inspect or tighten the screws in this area.

Mon Aug 27, 2001

Cont...

Pictured top right - Close up rear inner attach.  I added extra screws here as apparently the part of the skirt takes a beating.  Screws spaced 2" typical.

Pictured 2nd right - I put screws in all the corners to hold the bag up.

Pictured 3rd right -  Adding more screws and checking position of bag.  I really wish someone who has done this was standing over my shoulder saying "thats fine, just great, don't worry about it."

Pictured 4th right - a view of the craft from the front with the skirt secured in key locations to hold it level and even all around the craft.

Pictured 5th right - The rear view of the craft... picture didn't come out to clear but the bag is hangin pretty even.

Tue Aug 28, 2001

1 hour

Well I spent most of the evening cleaning the garage...ahem I mean hovercraft workshop.  I did insert two of the lift duct formers back into the duct.  I noticed the duct was out of round slightly.  My plan is to fiberglass the outside of the duct with the disc formers in place.  This should hold the duct to the correct position.  I will reinsert them when I pour the foam around the duct.  I also filled some of the assembly holes from my UH lift fan.

Pictured top right - I removed the two discs from the lift duct former jig.  I inserted one discabout 2.75"  down from the top of the duct.  I had to lightly tap it into position with a rubber mallet.  The duct was out of round right where it needed to be round in the plane of the fan rotation.  I inserted the second former into the duct about 1/4" below the duct top.  This part of the duct was probably never perfectly round because when I built the duct I had the formers much lower.  They weren't in the plane of rotation. I didn't know where that was going to be so I guessed. I was wrong.  I will fiberglass the duct now with the formers in place I needed to fiberglass it again anyway as there is only one layer of 4oz cloth around the plane of rotation.  I need to beef it up in case the fan breaks.  Not sure how much of a difference this will make I am primarily concerned with holding the duct round.  I will put these discs back in when I foam around the outside of the duct.  The second time I insert them I will have a good idea how well the fiberglass holds the duct round.

Pictured 2nd right - This is what I am using to hold the lift fan to get it ready for glassing.  I am using my vice to hold a 1" dowel parallel to the ground.  The fan can freely rotate on the blade.  I used some plastic wood to fill some of the holes in the fan that were to to construction by UH.  I will sand these and the rest of the fan surface and hopefully glass tomorrow.

Pictured 3rd right - The front of the fan... I hope that dowel doesn't fall out of the vice :)

Pictured 4th right - Here is my cleaned up work space... I dramatically increased the amount of work space and decreased the amount of dust.

You know if you ever think of building one of these things try and find a partner.  It sure helps to have two people and working is usually more fun when you have someone to talk to.   For my next hovercraft (wife - "In your dreams pal!") I am going to try and get my Dad to be my partner.  He is retiring soon and I think this would be a great project.  I just need to finish this craft so I can infect him with the hovercraft bug.

Wed Aug 29, 2001

1 hour

This evening I forced myself to go out and glass the lift fan.  I also did some sanding on the craft previous to that.

Pictured top right - I sanded the lift fan smooth and glassed the the fan with a 4oz cloth.  The first blade was the hardest... the rest went a lot easier.

Pictured 2nd right - I rounded all of the exterior edges round where the deck ply meets the outer attach strips in preparation for glassing.

Pictured 3rd right - I also sanded the deck ply seams lift duct exterior in preparation for glassing.

Fri Aug 31, 2001

1 hour

Thursday I watched the kids so no time to build... This evening I did some sanding on the hull corners where the deck ply meets the outer atach strips and I fiberglassed the lift fan with a 6 oz cloth.  This is the second layer on the fan. 

Pictured top right - I fiberglassed the lift fan with a 6oz cloth.  In preparation I cut all the edges from the 4oz off and filed off epoxy bumps that were left on the fan blades.  I still need to balance the fan.

Pictured 2nd right - A close up showing how I rounded the cornersin preparation for glassing.

Sat Sep 1, 2001

6 hours

Pictured top right - Here I am preparing the hull for glassing.  In order to get a nice straight clean edge I am using duct tape to mark the area where I want the glass positioned.  The glass will overlap onto the duct tape and I will cut it down the edge when the epoxy starts setting up and remove it using some fresh epoxy to seal the edge.

Pictured 2nd right - I only ran the tape up to the lift duct.  The rest of the hull should be under the cockpit.

Pictured 3rd right - This shows all of the fiberglass that I am applying to the hull.  It is 6oz standard cloth.

Pictured 4th right - This photo was taken after I did all of the fiberglassing.  You can see how the fiberglass overlaps onto the duct tape.  When it starts setting up I will use a razor knife to cut along the edge.  I will then remove the tape ad seal the edge with some epoxy.

Pictured 5th right - I also used a 4" strip of 6oz cloth to seal all the plywood seams on the hull

Sat Sep 1, 2001

Cont...

Pictured top right - I used 4 strips of 5" wide 6oz cloth around the top of the lift duct.  The strips went 3/4 of the way around the duct so I offset the seams.  This should hopefully hold the duct round - the former discs are in place.

Pictured 2nd right - I sealed the idler mounts and hull around the idler mounts with epoxy.

Pictured 3rd right - a view showing the epoxied hull ply seams and the fiberglass that runs around the hull.  It covers 3" on the deck and bends down to cover the attach strip.

Pictured 4th right - The hull with all the seams and edges fiberlassed and sealed.

Pictured 5th right - I also sealed the ply deck in front and on the sides of the lift deck.  I also used several pieces of cloth around the attach strips at the bow point.

Pictured top right - I used the Olfa razor knife to cut along the edge of the duct tape.  I waited about 2 hours after applying the epoxy.  You can tell if its set up enough by running the knife down a small section and seeing if you disturb the fibers at the edge.  It should not disturb them.  If it does wait longer. 

Pictured 2nd right -  After all of the duct tape was removed I coated the edge and top of the fiberglass with more epoxy to seal it better.

This concludes the fiberglassing of the hull. At least I hope it does.  Tomorrow I will finishing sanding and filling the thrust duct lip and hopefully late tomorrow or early Monday I can fiberglass it.  I will also finish attaching the skirt.  I am thinking of taping off around the hull and painting around the outer skirt attach strips.  This would save me having to remove the skirt for painting.  I am just not sure at this point what color I want to paint it... probably white. 

I have several ideas for how I am going to build the control system.  Probably the best way is with a push pull cable.  Unfortunately it is the most expensive.  I have been looking at some Weson push pull cables and I think I will be looking at $150-$180 CAN for a 6 foot cable.

Sun Sep 2, 2001

4 hours

Today I sanded the thrust duct lip radius more... its almost ready for fiberglassing.  I also epoxied the lift fan again and built a prop balancer.  I sealed the outer edge of the hull where I fiberglassed yesterday with one more coat of epoxy.  I don't think the hull top ply will delaminate now!

Pictured top right - I trimmed and filed the fiberglass on the bottom of the outer attach strips and applied one more coat of epoxy to the fiberglass all around the hull including on the bottom edge of the outer attach strips.

Pictured 2nd right - I continued sanding the thrust duct lip.  Hopefully one more sanding session and it will be ready for glassing.

Pictured 3rd right - I epoxied the lift fan again to smooth out the blades.  I didn't apply quite enough epoxy when I previously glassed them.

Pictured 4th right - This is the prop balancer rig I made from a $3 level, some twine and 3 pieces of 1" diameter wood dowel.

Pictured 5th right - I drilled holes about 3/32" in the center of the dowels 3 in total.  The twine ties onto the center of the level vial and runs through the holes in the dowel.  The prop or fan sits on top of this unit with the dowels going through the prop center where the shaft normally goes through.  I will post more pictures of this tomorrow.  I tried to balance the prop with resin today but one of the blades is much heavier.  I will need to drill some holes near the center of the prop and fill with pennies or lead and then epoxy into place.  This will be adding more weight to the prop but I don't really have much of a choice.  I need to run a balanced prop and lift fan to reduce vibration and increase performance.

Pictured 6th right - I used the remaining epoxy to further seal and strengthen the inner deck between the motor mounts.

Mon Sep 3, 2001

8 hours

Pictured top right - Balancing the lift fan... two stacks of pennies 8 each stack.  I am going to try something heavier ... I glassed the light blade

Pictured 2nd right - Here is the jig I built to balance a prop or fan.  The level is underneath.

Pictured 3rd right - I drilled oversize holes into the fan and inserted stainless steel bolts that attach to the mounting hub behind.

Pictured 4th right - This is what the lift fan looks like mounted... its almost ready to run.

Mon Sep 3, 2001

Cont...

Pictured top right - The fan spins nicely...

Pictured 2nd right - This is typical blade clearance to the duct wall ... about 1/8"

Pictured 3rd right - clearance on the otherside... about 1/8" as well... the picture looks deceiving.

Pictured 4th right - The thrust duct is ready for glassing.

Up for next week.... finish balancing the lift fan, paint the outer attach strips white, finish attaching the skirt, and glass the thrust duct so I can mount it to the craft.  I need to do the above in the order stated.

Tue Sep 4, 2001

2 hours

Yes I did do work on Tuesday... just too lazy to put it online.

I balanced the lift fan.  Wow this thing was out of balance.  I used some bolts and lead fishing sinkers.  I sunk them in and filled with epoxy.  It is really hard getting it in balance.  I would add some weight one one side and it would throw out the other side.  I ended up drilling some holes where I didn't need them.  I filled them with epoxy and a smaller dowel.  I don't think this is the best way to balance a fan... in fact I know it isn't.  I should have balanced it as best I could before fiberglassing.  Oh well theres always the next one.  I just hope this one doesn't blow apart while in use.  I ended up with 7 holes in total as pictured right.  If anyone with experience see's a potential problem with this please email me and let me know.  Thanks.

Wed Sep 5, 2001

2 hours

Today I inhaled a lot of dust and epoxy paint....hmmm epoxy paint....

Pictured top right -  I masked the outer attach strips bottom and top in preparation for painting.  First I sanded them with a 150 grit paper and clean with a damp towel.  The paint is just so I don't need to remove the skirt to paint the entire craft I can just mask just above it.  Boy I hope I paint this thing white.  Two-tone anyone?

Pictured 2nd right - White Epoxy enamel spray applied in what I consider a light coat.

Pictured 3rd right - A close up of my painting prowess.  Notice the ugly fiberglass cloth seam... I don't care it will be under the skirt.  Normally my compulsize tendancies would have made me sand and fill... to hell with compulsion, to hell with compulsion, to hell with compulsion...Help please....See I did inhale too much paint.

Pictured 4th right - Here is the thrust duct in all its 54" of manly glory.  I can say that cause this is my web page.  I sanded the inlet radius down to 1/1000" precision... well ok maybe its only with 1/8".  It looks damn pretty to me.  I will glass this puppy on Friday or Saturday.

Pictured 5th right - One thing thats a pain in the ass, again my web page, is that you need to fill all those cuts you made to bend the duct.  I used that light weight drwall filler.  Works really well.  also notice I had to fill around the 1/8" ply edge.  I chose not to inlay a 6" duct ply ring into the foam but instead used a (15"?) duct ply ring. The filling compound worked really well for this also.  Things that worked well for sanding.  A small palm sander for sanding near the duct ply on the inside.  A piece of 150 grit sanpaper that you hold and curve from the top of the dut around to the inside and work in/out of the duct.  Use a 400 grit sandpaper to smooth it out.  I cupped the 400 in my hand around the outer radius and worked it around the duct.  It also really helps to have the duct on a spinable stand like pictured here. 

In a couple of hours I will go give the attach strips one more coat....

Thu Sep 6, 2001

Today I removed the masking tape and plastic from the hull. The tackstrip paint worked out great.

Pictured top right - The bow tack strips painted whit.

Pictured 2nd right - A view of the painted tack strip. 

I will let the paint dry till Saturday... only because I am booked with other commitments.  I am planning to finishing attaching the skirt and to have it hovering. 

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