Just a weeeeeeee bit of frustration

So, I wanted to get a custom intermediate shaft made for my Python Drive.

 

So, what's a Python Drive? you ask. Well it's a Constant Velocity Joint, actually two Constant Velocity Joints (part F & part I) attached to each other by an Intermediate Shaft (part G) that are in turn attached to a Thrust Bearing (part B) which in turn is attached to the Propeller Shaft (part K) and that whole rig is attached to the Engine Gear Box. Whew!  

Got that? Yes, move on. No? Ok basically it works like this, The thrust from the propeller is transferred up the Propeller Shaft (part K) to the Thrust Bearing (part B). The Thrust Bearing is solidly mounted to the superstructure of the boat (framing) so that it can push the boat through the water. The output from the Transmission is transferred via the CV joints (part F & part I) and Intermediate Shaft (part G) to the Propeller Shaft (partK) via the Thrust Bearing (part B). Whew!

So, why all these extra parts? you ask. Well in a conventional boat the arrangement is for the propeller shaft to be hooked directly to the engine's gearbox. The thrust from the propeller is transferred to the transmission and its mounts or to the engine and its mounts. Alignment of the two mating flanges, propeller flange and transmission flange are critical, usually less than 2 or 3 thousandths of an inch. 

Photo Credit: http://www.todddunnmicroyachts.com/tortuga/repower-2.html

The setup above you can see the misalignment of the Propeller Shaft flange and the flange on the Transmission. This situation normally requires the adjustment of the engine or transmission mounts to get the two flanges to meet within tolerances. The process can be tedious. Depending on when/where the adjustments are made, in the water, out of the water etc. the alignment can fall out of tolerance. Alignment call also change due to transmission mount wear, engine mount wear, shaft cutlass bearing wear or grounding etc. 

This is where the Python Drive (and there are others that work on the same/similar principals) come into play. A constant velocity joint allows a wide range (or narrow) of movement between the driving force (propeller shaft) and the prime mover (engine) or in the case of a car the drive shaft and the wheel. They work something like this.

In the case of the Python Drive the range of motion is much smaller than on a car, between 2 and 8 degs. Zero degs of alignment is not recommended as it will prevent the CV joints from self lubricating. 

This angle allowance works in all orientations so it allows for a much higher degree of misallignment without possibly damaging the transmission or your engine and their mounts. There is also a fair amount of fore and aft to account for flexing of mounts in those directions. The Thrust Bearing (part B) is also soft mounted with rubber inserts to allow some degree of movement of the propeller shaft.

Photo Credit:  http://www.cruisersforum.com/forums/f54/installing-a-3jh4e-yanmar-rant-36940-2.html

 Above you can see a typical Python Drive installation as described.

So, what's that all got to do with me wanting a custom Intermediate Shaft (part G)? you ask. Well, the company that makes the Python Drive is in The Netherlands (Holland). They no longer have a Canadian Distributor. I contacted them directly to get info on having a custom 1m (meter) shaft made for my model of Python Drive. The quote was reasonable:

Shaft: €55 - $80.00
Shipping: €80 - $116.25

Payment has to be made via direct bank transfer to their account in the NL. So off I go like a hurd of turtles to the bank this morning to get the money sent off by International Money Transfer. The teller hands me the quote:

Shaft: €55 - $80.00
Shipping: €80 - $116.25
Bank surcharge: $30.00
EMT: $100.00
Total: €224.51 - $326.25 Cdn

After I picked my jaw up off the floor I had her tear that up and got out of there as quickly as I could. That's nuts! Over 4 times what the cost of the part is. So sent off a flurry of emails to the company, on hold, off hold, looking for a way to transfer the money etc. I spent about 2 hours online this afternoon looking at online services that could do the transfer to a company account. The first six were no go, they only did to individuals. On my last attempt before giving up I stumbled across an online service from the UK Xendpay that could do a direct deposit into the company's account. Their rates were reasonable. In the end all said and done it cost me:

Currency exchange:     $186.52
Transfer Fee:     $6.99
Payment Fee:     $4.74
Delivery Fee:     FREE
Total that you pay:     $198.25 (Cdn)

So I'm happy. I saved a chunk of change ($128) that'll be better spent on some more boat stuff than paying for some Bank Manager's kids University PolySci or Underwater Basket Weaving text book. :-) 

So, why do you need an custom 1m Intermediate Shaft (part G)? you ask. Well I guess I didn't explain that part. If you remember back earlier in the blog I told you about stretching the boat 1m in length. Well I need the engine to stay as far forward as possible near the Center of Gravity (CoG) as possible. If I wasn't able to get the custom shaft I was looking at having to have a custom Jack Shaft (shaft with two mating flanges) made locally (approx. $350) to span the gap between the transmission and the Thrust Bearing (part B).

Whew!

Thanks for looking in. 

Feel free to carry on with your regular Interweb browsing activities.

This ain't Pixar

This is no Pixar animation! :-)  I've never done an animation before. It was really clunky to do in Sketchup (more likely 'cause I have no idea of what I'm doing) but I was trying to illustrate how I'll use a Gin Pole to flip the hull over.

I've omitted the tag lines & come-a-longs that'll be used to steady the hull as it turns and pull it sideways. The white pole on the left is the Gin Pole. It's a 6" X 6" pressure treated timber 16' long. 4' of it will be buried in the ground. It will have to chain stays anchored into the ground to keep it vertical. The 6 x 6 is able to handle a compressive load about 25 times that of the weight of the hull and the buckling load is at least 5 times the weight of the hull. I think it'll be safe enough. Lifting power will come from a 2500 lb electric winch.

If I have time I'll try to do a better animation. Standby.

It may have been

a holiday for our friends south of the border but the work never stops in the Big Blue Boat Building Shed!  :-)  I put the kid (Thomas) through his paces for a few hours this morning sanding the keel and bottom panels.

Here he is going down the sides with the RO smoothing things out a bit more. I'll likely have a few small spots to fill but otherwise it's pretty much ready to be sealed with a few coats of epoxy.

I busied myself bringing out some epoxy & my 'Sticky Stuff' dispenser etc. while I turned Thomas loose on the bottom panel (stbd side) with the inline sander. He used it a bit on the keel sides but it's pretty heavy and takes a fair amount of muscle to use properly. It works much better when you have gravity working on your side.

Also gave him the Flexicat to try. I don't think he liked it as much as the air powered sander. It too takes a lot of muscle to get it working properly. He troopered on though. I'll give him credit for that.

 

The Kid needs to take a few days off to recover (or hang out with his buddies) so I'll be on my own for awhile. That's Ok, what's left to do now is just little detail stuff. Should be rolling out epoxy to seal up the fairing compound by Monday. Standby...

Quick update

Went out to the shed at 08:00 and it was already 85 degs in there! I knew I had to get some Quikfair on the keel so we can sand it tomorrow when the help arrives. I managed to get it done in about half an hour but I was soaked with sweat. It must have been 95 degs up on top of the boat so I shut it down for the day.

That is all. Continue with your normal browsing activities.

More hands make light work

A couple weeks ago I put an ad on some Facebook pages. It went something like this.

"Do you have an able bodied teenager sitting in your basement playing video games all day and raiding your fridge?  I have need of one to help me with a project."

I got a response back within' 10 minutes. "You've described my kid to a Tee!" "When can he start?"

The deal was struck. The kid was conscripted into sanding service. A date was set and today was that day! Welcome Thomas my new boat shed helper.

I gave him a 5 minute intro into the fine art of sanding fairing compound and let him loose! He jumped right into it. A little awkward at first getting used to the ole' electric RO but he caught on pretty quick. There was no mercy. It was hot when we started and only got hotter. We did manage to work almost 5 hrs on the boat before it was too hot to spread more compound so we called it a day. He'll be back on Wednesday for more sandinsanity!

Standby...