# New project, I'm in over my head.....



## bpimm

Working up a project for my Dad, His hobby has been wood boats, His/our first boat was a Keeler craft 16' lapstrake bought in 1965, it was a 1961 boat so I was 4 years old when we bought it, We still have it, in fact my brother and I are just finishing up it's third restoration. Actually his first boat was a folding canoe that he built when he was about 12, it was about 6 feet long and folded in half, had wheels he hooked on it and he towed it behind his bike down to the local slough to paddle around. He has since built /restored several wooden boats including strip built kayaks that he loves to go paddling in, unfortunately at 80 his hands aren't what they used to be, due to a chipper accident his right hand has only the thumb and forefinger left and the arthritis has left it pretty non functional and the left has arthritis as well plus there is the non repairable rotator cuff, you get the idea, so paddling has become very difficult. 

Our solution is to build an outboard motor for the kayak so he can still enjoy getting out on the water, this is a 3 generation project with my son involved with the motor and controls as well.

What I have designed is a three piece aluminum housing that threads together, I'll include drawings with the post, I found a "high efficiency" prop form a company that makes electric Kayak motors, imagine that, so we could just buy the whole thing for a little over 2 grand but where's the fun in that right?.

I have the design pretty close but where I'm having issues is figuring out the work flow, 2 of the parts need to be machined from both ends and stay concentric and the parts have to thread together and stay in alignment.

 I have a pretty good lathe, I think, but I only have a 3 jaw chuck so if I flip the part it wont run true and what I have to turn from the other end is the other bearing pocket and the attachment threads so even a few thou could be a problem for alignment. I do have a 5C collet chuck but that only gets me to 1" and the material I'll be working with is 3" and all the turning is ID turning so I don't think turning between centers would work plus I don't have mandrels or dogs. I do have a small cnc mill, Grizzly round column drill/mill but I don't think the accuracy is very good, it's pretty worn and has some vibration issues. I also have a decent manual knee mill although my tooling is limited for all the machines. Oh I do have a 4 jaw chuck on my first lathe but it is a well used 1905 Seneca Falls star lathe, not going to provide the accuracy needed.

My background is not machining, I started out in the electronics industry, followed by running heavy construction equipment for a bunch of years, The Seneca falls lathe came first as a gift... "Get it out of here or it's going to the dump" I worked on it and got it running and fell in love with making chips so I bought the cnc mill to play with and quickly found it's limits. The bigger lathe and mill came along when I wasn't even thinking of new equipment but a friend of my brother's was selling his family's equipment, they hadn't used it in about 20 years and he was trying to clear out some space so I bought them.

Here is a screen capture of the assembly in Fusion 360 for reference.


There are 4 components in the body in this view, the nose cone which threads into the center section which the motor mounts in, then the tail housing has the prop shaft, bearings and seal and threads into the center section using a small love joy type coupler to hook to the motor. This view also has the prop hub modeled on the back.

Here's my thought process for work flow hopefully you guys can point out the holes in my thinking and maybe fill some of them as well.
Start by making the thread gauges for the 2.375 X 20 LH threads, then start the center section and cut the back side where it mounts to the tail section, get the internals finished on that end. Follow that with starting the front side of the tail section and do everything on that side then screw the center section on to it and finish the front side of the center section while mounted to the tail section that's still in the chuck. At this point I could rough down the outside of the center section.
Then make a blank female thread so I could thread the tail section into it and finish the back side of the tail section and rough down the OD.
Next I would rough out the nose cone inside and threads, probably do the strait bore as well.
Then put the nose cone in the cnc mill and let it contour the inside of the cone.
Now move the female thread blank into the cnc mill, mount the tail section and let the cnc cut the outside profile on the tail section followed by the outside profile of the nose cone. at this point all the parts should be roughed out and I would need to do a male thread blank in the lathe so I could mount the center housing and tail section to finish the outside, hopefully just a bit of filing and sanding/polishing, followed by mounting the center section and nosecone for the finishing process.

I chose left hand threads because the rotation of the mill cutter will be tightening the part as it cuts the outside profiles so I'll have to flip my lathe tooling or work on the back side with the lathe running backwards to get the same tightening effect, I figure that is easier than reversing the direction of the mill and getting LH cutters for it.

 I have included drawings of the parts in pdf and dwg format and a screen capture of the tail section because the drawing didn't pick up the hidden lines on the inside like it did on the other 2 and I haven't figured out why yet.

This is the most ambitious machining project I have come up with yet, am I nuts for trying this? any and all suggestions are welcome including the "What the H*** are you thinking type" LOL.

I'm sure I left out some needed information so please don't hesitate to call me on what's missing.

Thanks
Brian


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## RJSakowski

bpimm said:


> Working up a project for my Dad, His hobby has been wood boats, His/our first boat was a Keeler craft 16' lapstrake bought in 1965, it was a 1961 boat so I was 4 years old when we bought it, We still have it, in fact my brother and I are just finishing up it's third restoration. Actually his first boat was a folding canoe that he built when he was about 12, it was about 6 feet long and folded in half, had wheels he hooked on it and he towed it behind his bike down to the local slough to paddle around. He has since built /restored several wooden boats including strip built kayaks that he loves to go paddling in, unfortunately at 80 his hands aren't what they used to be, due to a chipper accident his right hand has only the thumb and forefinger left and the arthritis has left it pretty non functional and the left has arthritis as well plus there is the non repairable rotator cuff, you get the idea, so paddling has become very difficult.
> 
> Our solution is to build an outboard motor for the kayak so he can still enjoy getting out on the water, this is a 3 generation project with my son involved with the motor and controls as well.
> 
> What I have designed is a three piece aluminum housing that threads together, I'll include drawings with the post, I found a "high efficiency" prop form a company that makes electric Kayak motors, imagine that, so we could just buy the whole thing for a little over 2 grand but where's the fun in that right?.
> 
> I have the design pretty close but where I'm having issues is figuring out the work flow, 2 of the parts need to be machined from both ends and stay concentric and the parts have to thread together and stay in alignment.
> 
> I have a pretty good lathe, I think, but I only have a 3 jaw chuck so if I flip the part it wont run true and what I have to turn from the other end is the other bearing pocket and the attachment threads so even a few thou could be a problem for alignment. I do have a 5C collet chuck but that only gets me to 1" and the material I'll be working with is 3" and all the turning is ID turning so I don't think turning between centers would work plus I don't have mandrels or dogs. I do have a small cnc mill, Grizzly round column drill/mill but I don't think the accuracy is very good, it's pretty worn and has some vibration issues. I also have a decent manual knee mill although my tooling is limited for all the machines. Oh I do have a 4 jaw chuck on my first lathe but it is a well used 1905 Seneca Falls star lathe, not going to provide the accuracy needed.
> 
> My background is not machining, I started out in the electronics industry, followed by running heavy construction equipment for a bunch of years, The Seneca falls lathe came first as a gift... "Get it out of here or it's going to the dump" I worked on it and got it running and fell in love with making chips so I bought the cnc mill to play with and quickly found it's limits. The bigger lathe and mill came along when I wasn't even thinking of new equipment but a friend of my brother's was selling his family's equipment, they hadn't used it in about 20 years and he was trying to clear out some space so I bought them.
> 
> Here is a screen capture of the assembly in Fusion 360 for reference.
> View attachment 268969
> 
> There are 4 components in the body in this view, the nose cone which threads into the center section which the motor mounts in, then the tail housing has the prop shaft, bearings and seal and threads into the center section using a small love joy type coupler to hook to the motor. This view also has the prop hub modeled on the back.
> 
> Here's my thought process for work flow hopefully you guys can point out the holes in my thinking and maybe fill some of them as well.
> Start by making the thread gauges for the 2.375 X 20 LH threads, then start the center section and cut the back side where it mounts to the tail section, get the internals finished on that end. Follow that with starting the front side of the tail section and do everything on that side then screw the center section on to it and finish the front side of the center section while mounted to the tail section that's still in the chuck. At this point I could rough down the outside of the center section.
> Then make a blank female thread so I could thread the tail section into it and finish the back side of the tail section and rough down the OD.
> Next I would rough out the nose cone inside and threads, probably do the strait bore as well.
> Then put the nose cone in the cnc mill and let it contour the inside of the cone.
> Now move the female thread blank into the cnc mill, mount the tail section and let the cnc cut the outside profile on the tail section followed by the outside profile of the nose cone. at this point all the parts should be roughed out and I would need to do a male thread blank in the lathe so I could mount the center housing and tail section to finish the outside, hopefully just a bit of filing and sanding/polishing, followed by mounting the center section and nosecone for the finishing process.
> 
> I chose left hand threads because the rotation of the mill cutter will be tightening the part as it cuts the outside profiles so I'll have to flip my lathe tooling or work on the back side with the lathe running backwards to get the same tightening effect, I figure that is easier than reversing the direction of the mill and getting LH cutters for it.
> 
> I have included drawings of the parts in pdf and dwg format and a screen capture of the tail section because the drawing didn't pick up the hidden lines on the inside like it did on the other 2 and I haven't figured out why yet.
> 
> This is the most ambitious machining project I have come up with yet, am I nuts for trying this? any and all suggestions are welcome including the "What the H*** are you thinking type" LOL.
> 
> I'm sure I left out some needed information so please don't hesitate to call me on what's missing.
> 
> Thanks
> Brian



An ambitious project indeed!  What size lathe?  At 3" O.D.  I would want more than 1/2" to 3/4" jaw grip.

For a custom thread, yes, I would make the thread gages first. I would then  turn the middle section internals, including thread from one end.  Next turn the tail piece internals leaving the O.D..  While the tail piece is still in the chuck, thread the center section on and turn the remaining internals.
Remove the work and replace with the nose piece stock and turn the internals..  Thread the center section and tail piece on and turn the exterior.  All that remains is to turn the exterior of the nose piece.  Remove the tail piece and mount the center section, back end first.  Shim chuck jaws as necessary to have it run true.  Screw on the nose piece and turn O.D. Since this is just an aesthetic surface, aq slight runout could be tolerated.  Blend in any imperfections with file and emery cloth.


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## RJSakowski

I friend of mine has a pedal kayak outfitted for fishing.   It drives a prop.  I forget what the top speed is but it was impressive.  A much simpler design and build if your Dad's legs are still functional.


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## RJSakowski

If you haven't considered it yet, a pulse width modulated speed control greatly extends battery life.  I'm still using one that I built over 30 years ago on my trolling motor.  I have infinite control from about 30 rpm to max.


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## bpimm

RJSakowski said:


> An ambitious project indeed!  What size lathe?  At 3" O.D.  I would want more than 1/2" to 3/4" jaw grip.
> 
> For a custom thread, yes, I would make the thread gages first. I would then  turn the middle section internals, including thread from one end.  Next turn the tail piece internals leaving the O.D..  While the tail piece is still in the chuck, thread the center section on and turn the remaining internals.
> Remove the work and replace with the nose piece stock and turn the internals..  Thread the center section and tail piece on and turn the exterior.  All that remains is to turn the exterior of the nose piece.  Remove the tail piece and mount the center section, back end first.  Shim chuck jaws as necessary to have it run true.  Screw on the nose piece and turn O.D. Since this is just an aesthetic surface, aq slight runout could be tolerated.  Blend in any imperfections with file and emery cloth.



It's a Jet 1440 lathe from years ago when they got them from URPE in Spain.

I like that, it cuts down making the blanks, but my confidence for turning the ellipse freehand is zilch. That's why I was going to let the cnc do that LOL. I could still follow your process and use the center section in the mill to cut the nose and tail shapes, or just the nose and if I made the thread gauge right I could chuck it back up to put the final polish on the parts.


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## bpimm

RJSakowski said:


> I friend of mine has a pedal kayak outfitted for fishing.   It drives a prop.  I forget what the top speed is but it was impressive.  A much simpler design and build if your Dad's legs are still functional.



1 knee replaced and the other needing it... Also hard to retrofit a strip built kayak.
	

		
			
		

		
	



It's going on the one on the right, the one on the left he built for mom. That pic is out the back of the Houseboat he built. He likes to cruise around in the houseboat and paddle from it as a base.


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## bpimm

RJSakowski said:


> If you haven't considered it yet, a pulse width modulated speed control greatly extends battery life.  I'm still using one that I built over 30 years ago on my trolling motor.  I have infinite control from about 30 rpm to max.



Definitely PWM with the advent of the 4 motor drones there are really good motors and controllers available really inexpensively.


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## rock_breaker

Impressive craftsmanship. Making the parts on your lathe in my mind is do-able with perhaps light cuts and careful chuck mounting. Your plan sounds reasonable, obviously minimizing the "re-chucking" is imperative. Good luck.
Ray


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## bpimm

Ok first step done. I can cut left hand threads.....





Got the male thread on the first try but it took 2 trys to get the female, something about boring it to the major diameter then threading.. was a little loose fitting..

I'll use the female gauge as the holder in the cnc mill, if I had a 4 jaw for the lathe I'd use it there as well.


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## Tony Wells

Thread gages of the same nominal size should never fit together (straight threads; taper threads are another story). Not to sidetrack your build thread, just something you should know. Not worth another thread to itself. Seems we have already discussed it somewhere anyway.


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## bpimm

I've read that. At this point I feel good to get threads to work together period. I doubt I could make a thread gauge to tight enough tolerances to work with anyone else's threads so I'm happy with having the two parts screw together. lol


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## Canus

You stated "something about boring it to the major diameter then threading.. was a little loose fitting.. ".  Shouldn't you be boring to the MINOR diameter then threading?  Then the grooves cut by threading would give you the major diameter.


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## bpimm

Canus said:


> You stated "something about boring it to the major diameter then threading.. was a little loose fitting.. ".  Shouldn't you be boring to the MINOR diameter then threading?  Then the grooves cut by threading would give you the major diameter.



Yep, I looked at my notes and read the wrong number, was really happy when I hit the bore dead on, cut the threads and wtf then I realized what I had done. more scrap in the bin...


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## Silverbullet

Nice lathe , great family project too. We're waiting for updates already , threading looks good on both pieces pictured.


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## bpimm

Thought I'd post some progress pics, I've got most of the internal turning done, here are the three pieces starting with the inside of the nose cone.


The center section.


the tail section with 1 bearing pocket cut,


all three


and screwed together.


I drilled some weight reduction holes inside the tail section.


Today the nose cone is slowly appearing on the mill.




When the nose cone is done the tail section goes in the mill for it's external shaping.

Brian


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## bpimm

Nosecone is off of the mill.




I also drilled the motor mount bolt pattern,


Motor mounted.


Tail housing is on the mill now. Starting to get excited...


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## brino

Wow!
It sure does NOT look like you're in over your head!

Great progress on an ambitious project.
Your hard work is paying off.

...and thanks for sharing it with us.

-brino


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## bpimm

brino said:


> Wow!
> It sure does NOT look like you're in over your head!
> 
> Great progress on an ambitious project.
> Your hard work is paying off.
> 
> ...and thanks for sharing it with us.
> 
> -brino



Honest, I've never made anything this complex, and I did have to make 2 of the center sections.... the first one ended up with RH threads on one end... I just couldn't get the threads to start. I kept taking another .001 off and after I was .010 -.015 over size by the dials I figured it out. lol.

I am very happy with how it's coming out, surprised too.


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## bpimm

Tail section just came off the mill, now for some cleanup.
	

		
			
		

		
	



all together.


Back to the lathe tomorrow.


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## bpimm

Turned the center section down to match the ends and sanded it down to 400 grit, how fine do I have to sand aluminum  to get a good polish?


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## rock_breaker

Not sure about the sanding but sure admire your work.
Ray


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## WarrenP

probably 800 grit or more then polish with a polishing compound. Check youtube there are lots of videos on polishing aluminum. B y the way, great job.


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## bpimm

Thanks for the compliments guys, my confidence is growing with this project. 

I'm using 6mm stainless rod for the prop shaft, both the motor and the prop are 6mm, I couldn't find a seal for 6mm so I got a 11mm seal and some 11mm stainless rod thinking I would make a spacer / bushing between the prop and outer bearing, this would give me a boss for the seal and put the thrust load on the bearing directly, I'm thinking of using Loctite 609 to hold the bushing on to the 6mm shaft. Will it need any kind of mechanical connection as well? Is there a better product for attaching and waterproofing the joint?

This will be my first time working with stainless so any pointers for drilling and boring the bushing true would be great. I don't have any metric drill bits or reamers, but I do have a tiny HSS boring tool that came in something I bought, it has worked well on steel and aluminum in the past and I'm hoping it can do the final bore in the stainless.

I tried to go over the 400 grit with 1000 grit and polish but the 1K didn't get all the 400 scratches out, I didn't think it would but I had it. I'll get some 600, 800 and 1200 to play with and see how polished I can get it...

I'm going to make a fiberglass cast of the tail section of the Kayak to mount the motor on so that will be coming up soon, I want to have this thing ready test even if it's just a prototype of the mount by the first weekend in August, we're taking 3 boats and the 2 Kayaks to a local wooden boat festival for the weekend.


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## mattthemuppet2

cool project! For polishing aluminium, I use 320->400->800->1000->1200->1500->2000->2500 then use Mothers Mag wheel polish and some tissue. That'll get you to a mirror finish and the polish offers some degree of protection. Make sure to use wet'n'dry sand paper and keep the paper wet. Otherwise it'll load up and scratch the work.


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## Mitch Alsup

mattthemuppet2 said:


> cool project! For polishing aluminium, I use 320->400->800->1000->1200->1500->2000->2500 then use Mothers Mag wheel polish and some tissue. That'll get you to a mirror finish and the polish offers some degree of protection. Make sure to use wet'n'dry sand paper and keep the paper wet. Otherwise it'll load up and scratch the work.



Just keep the sanding crap off the ways of the lathe--I use a big piece of heavy cardboard cut to size when I do thi.


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## bpimm

I put the prop shaft together this morning, drilled and bored the 11mm stainless, only took 3 tries to get it right... the rest was pretty strait forward, run a die over the end to thread it and drill a cross hole for the drive pin for the prop.

here is the motor mounted with the lovejoy coupler installed




the tail section with the bearings and seal in place.




shaft in.


Prop installed.


Motor on, it goes together really easy.


The wires will come out through a hole into the shaft coming down to the motor from the boat then the nose cone can go back on.
I got a foot of aero tube for the shaft,




I don't have a TIG welder so I'm going to build a jig to hold it all together and take it to someone to weld the shaft and scag on.

I'm also working on the mounting bracket for the back of the Kayak so that's coming up soon.

 I'm off to get more sandpaper so I can finish the polishing and drill the holes for the wires and pin wrench.

Thanks for all the encouraging words.


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## savarin

For polishing aluminium use the grades of papers Matthemuppet stated, I use wet-n-dry papers and lubricate it well with WD40.
Followed with tripoli then rouge.
This will bring up a brilliant diamond like shine, then a coat of car wax polish as a bit of protection.


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## bpimm

Here's what I came up with for the mounting bracketry to hang the motor on the back of the Kayak. First off the Kayak will get a fiberglass cast made of the back tip of the boat that will pin onto it via a hole that is already on the Kayak then this bracket setup will mount to that form fitted cast, In theory. The cast piece will have a 1/4" thick strip along the rear for the bracket to bolt to.

The first bracket that bolts to the Kayak


This is followed up with what I call the lift bracket because the motor needs to be able to tilt up for shallow water, beach landings or hitting debris in the water.


Then the rudder bracket that allows the rudder to pivot


Then all assembled.


And after making some chips.







That's where I'm leaving off today, I need to finish sanding and polishing the motor housing and the aero tube and get it all welded together.

I need to find a good TIG welder in the local area that can make some pretty welds so I don't have to sand and polish out the welds, I know that's not me!


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## Mitch Alsup

I don't think you are in over your head at all..........


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## brino

Brilliant!
-brino


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## bpimm

I got the parts welded together and now I have a problem, I was hoping I left the housing thick enough so the welding wouldn't deform it enough to mess up the threads but it did. the threads will start and screw in a ways but they get tight after a turn or so. 



I'm thinking I need to make a tap to clean out the threads where they got deformed, I tried using a 1/2" x 20 tap as a scraper in the weld area to clean up the threads but it didn't work. 

I have wires to measure the existing male threads so the question is how much bigger than the thread that I want to fit does the tap need to be? Also do I start with a larger major diameter also? I think I would have to.

 I found this thread size on a chart but I didn't find any LH taps or RH either so I guess making one is the only way I'll get this project past this failure point.

2 other concerns that come up now that I can see it all together, my hinge pins on the rudder bracket are going to be under a bit of stress at full power so we'll see if they hold up and I think I am going to need a skeg to protect the prop from debris which means another bit of welding.

So any and all advise for making a large tap would be very welcome. Would mild steel cut the aluminum for a couple uses?


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## brino

bpimm said:


> I guess making one is the only way I'll get this project past this failure point.



....but.....
.............it's so  beautiful....
...................the dream cannot die yet......

if the aluminum cylinder did deform from welding it is likely not cylindrical anymore....likely both oval and bell-mouth from the weld shrinkage when cooling. (beautiful welds, by the way....)



bpimm said:


> Would mild steel cut the aluminum for a couple uses?



I bet it would! I agree that making a tap is an interesting solution and worth trying.
If I had to do it, I would make a male thread to the same spec. as the female thread, and then mill some longitudinal slots to produce a flat cutting face.
Ideally, there would also be some relief behind the cutting edge. Four slots minimum, but since you're working with such a large diameter (2-3/8") you could fit any even number to be sure you had good counter forces, perhaps any multiple of 4.

Did you make the thread gauges you talked about in your first post?
If made of steel, maybe those could be re-used as dies.

Wow I would hate to see all your effort not lead to a working result.
-brino


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## f350ca

I hope the profanities weren't too bad, if me they would have been.
Before you remove any material could you make some type of die that would reform the cylinder. As brino said chances are its gone out of shape, removing material will make it loose if thats the case.
I agree, beautiful welds.

Greg


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## bpimm

Wish I could claim the welds, local welding shop. I think he'll be sending me his machine work now so that's cool.

I'll do some measuring and see if I can figure out what happened but even if it's a little loose the orings should still seal.

Brino I was thinking the same thing with milling the cutting edges into the tap, the test threads I made were Aluminum so they wont work. I feel I need to make the tap a few thousandths bigger than the male thread for clearance I just don't have a good feel for how much bigger and I don't want to make them in .001 increments to find out, not that I could hit .001 anyway. 

It's not going to die, I'll get there somehow.

Greg, I'll try to measure it out and see if it's out of round or just the weld spot deformed, trying to imagine what a re rounding die would look like.


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## T Bredehoft

And when they ask, "Where'd you get that really great motor?" what are you going to say? ....


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## bpimm

T Bredehoft said:


> And when they ask, "Where'd you get that really great motor?" what are you going to say? ....



I'll probably have a huge grin while saying I built it...


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## bpimm

This morning I couldn't stay away from the shop and this happened.




and then this happened.


the nose cone goes in all the way but the tail section is about a half turn short. I think the edge where the weld is pulled in and is to tight on the oring now, I think I can file the chamfer in that area to get the clearance back but I need a better file for that, all my half round files are way to coarse. But even as it is it should work so full steam ahead again. I'm headed out to Dad's to start the cast of the Kayak today. Still hoping to test it this weekend at the wooden boat festival.

Thanks for all the help and support guys.


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## bpimm

The first layer of the cast is on, we'll see how it looks tomorrow.


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## Creativechipper

Absolutely fantastic, inspirational for what is possible and doable.
Very nice work!!


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## RJSakowski

bpimm said:


> Turned the center section down to match the ends and sanded it down to 400 grit, how fine do I have to sand aluminum  to get a good polish?
> 
> View attachment 271246


I used to make spherical aluminum mirrors.  I would polish on the lathe using 600 grit wet or dry with WD40 for a lubricant.  The WD40 retained the aluminum particles, some of which would oxidize to aluminum oxide.  With some pressure, I would get a mirror finish.  A self cleaning car wax sich as the old Turtle Wax contains a fine abrasive which would speed the process.


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## bpimm

The cast came off this morning, Dad's relieved he thought I had glued a bunch of junk to the back of his kayak lol. I cut it down to what I wanted and bored a hole to line up with the holes in the kayak.



This is the hole in the kayak


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## bpimm

Tonight I beded in the bracket to the cast. I'll. Drill it and bolt it in case the epoxy ever let's go.



Today we wired it all up, my brother has been working on the controls, and tested it out. Wow this thing pushes water. It could be a rather fast kayak, we'll see this weekend. 
Once the bracket cure's I can work on the final assembly and making the last few parts.


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## Downunder Bob

Definitely not in over your head, that is an excellent project and very well done.


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## Firestopper

Excellent work and well within your skillset. Where did you source the aero tube?


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## bpimm

firestopper said:


> Excellent work and well within your skillset. Where did you source the aero tube?



Thanks, my skillset is much broader after this project...

The aero tube came from  Wicks aircraft and motorsports.


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## bpimm

A little bad news today, I was working on one of the brackets to hold the steering servo and the computer driving the CNC Mill decided it had reached end of life in the middle of the part. Woludn't reboot. I tried it's HD in the computer that drives my cnc plasma but it wouldn't boot, it got a lot further than in the original PC. All the power supplies are there so it looks bad.

I'm going to make a part to lock the steering strait so we can test the motor, just will have to run strait and turn with the paddle.

Damn computers anyway.


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## bpimm

Had a great weekend on the water and got some testing done on the motor, Way more power than we need and a better motor controller is in the plans. the minimum stable turn on speed is 4 MPH, once you're moving you can slow it down a little more but it's a little unstable. My brother has found a controller that should do the trick. At full power we think it limited to hull speed at 6.2 MPH.

Here are some VIDEOS that my son shot.

The first one is powering away from the dock at minimum turn on speed followed by a full power pass.
The second one is a full power pass with some fake paddling for the crowd on the dock..
Third is when I was manually adjusting the speed down for a running minimum.
fourth is just another pass.

Overall it was a success, we have more work to do, like fix my cnc and get the steering and lift installed, also going to look at shortening the length, I arbitrarily chose 4" of water over the prop to combat cavitation but it drives the back of the Kayak down when you're under power so I don't think it needs to be so deep.


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## brino

That looks like some fun "field" testing.

What battery are you using and what's the predicted discharge time?

Thanks for sharing those videos. I wish I could give more than one "like".
-brino


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## bpimm

We're using a pair of 5.0 AH hobby lithium packs similar to These. Discharge time is totally dependent on speed at the slowest cruise I got it down  to probably 2-3 hours, full speed who knows. When we tested it in the hot tub, pushing against the side, the slowest start up witch gave us 4 MPH cruise which is still pretty fast it was drawing 7 Amps IIRC, at full speed which got us to 6.2 MPH it was drawing 45 Amps. So if we can get it slower it will last longer, if I remember my calcs right a 5 amp draw would go 2 hours, and if we could get it down to a 1 Amp draw it would go 10 hours.

Once the new controller is online we can do some more testing for the battery life, can always add more batteries as well, they're less than a pound each.

It was fun testing, I can't wait to try it with steering. We even came in second in class with 1 boat in the sailboat class, lost to a local by 2 votes with a beautiful boat that won best in show last year, and we ended up finding it a new home with someone that will enjoy it and take care of it. Dad's been thinking of selling it for several years because we just don't use it, and a local guy fell in love with it, good for everyone.


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## bpimm

Finally got the mill back up and running, had to spring for a smooth stepper as the new old computer we put together out of spare parts wouldn't work.

Now the part I was making when it died is done.




This part mounts to the lift bracket and the servo mounts to it.



Then the servo,





all together.






Now it's on to making the lift mechanism. And getting some proper hardware...


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## bpimm

I've been working on the lift mechanism, first attempt failed, the linear actuator I got was to small, it could lift the motor but couldn't hold it. I ordered a new one that is a lot stronger and unfortunately a lot bigger also. Couldn't find anything just a little bit bigger...
This is the first one mocked up.





This is the one that can hold it up.




I made a couple shoulder bolts to mount it.





this second one has a step for the adjustment slot on the lift arm.

The whole mechanism together.



I still need to make a list and get all the proper stainless hardware.

and videos of it working.









Now for some more glass work, I need to add several layers to the area the linear actuator bracket will mount, I'm going to use flat head screws from inside the cast so I need it thick enough to countersink the heads so they don't scratch the boat, then it will be screwed on with a wet layer of glass for a perfect fit...


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## bpimm

It's off to my brothers shop to get the controls finalized. Here are a couple quick videos of it steering and running slow.

steering

Slow speed

That should be slow enough. I need to work on the servo saver, it's preventing it from getting to a full 90 degrees one way. I want to get a full 180 degrees of swing so it can pivot the Kayak in place.


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## RWanke

You definitely THE MAN!


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## Creativechipper

such dedication, congrats on the progress!!


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## bpimm

Thanks guys, this has been a really fun project so far and has really stretched my machining abilities and my thought process for incorporating the machining with the rest of the fabrication world.


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## Silverdrgn

Awesome build! Congratulations on the progress thus far. Considering the few bumps you ran into, did you have all this designed before machining or did your approach involve more of a successive path? I often approach small projects successively however this seems to be more complicated. Thank you for posting and great job being wonderful sons and brothers to each other.


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## bpimm

Thanks, I follow the successive approach, I designed the motor housing without any thought for how I was going to attach it to the Kayak, then worked up from there. In the early days we were even talking about cable controls for steering but the cable routing just got real messy which brought in the servo, then a joke about needing power trim brought forth the linear actuator for lift. I'm not sure if it was the successive approach or the snowball out of control down the hill approach.. LOL

My brother has the software side about 90% done so were moving on to the packaging of the controls, looking like a industrial type of joystick is where it's headed now.


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## Silverdrgn

Lol, seems like you guys are at the top of the hill by the looks of the project. Again great job guys. Im happy you chose the electrical route instead of cabling since it may have gotten a bit hairy the way im thinking of it. The joystick control sounds like a good option since it will allow the movement you need to steer. Pergaps you can check out arduino controllers. They have loads of options including joysticks. Just a suggestion.


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## bpimm

Arduino was a front runner until Gary found the motor controller he's using now, from what he's said it has more computing power than the Arduino does, it's even controlling the steering servo. Hopefully he'll chime in here, he can explain it much better than I can.


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## brino

bpimm said:


> Hopefully he'll chime in here.



Hope so. 
It sounds interesting.......I'd like to know more about it.
-brino


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## bpimm

I think he will, He's back to the Arduino controlling the motor controller now... I think...


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## bpimm

Got the motor and controls back from my Brother and it looks like it's going to work good. We'll be taking it out tomorrow for some testing.
Here is a quick video showing the controls and their function.

video


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## bpimm

We got some more testing done, went pretty good... except for our own stupidity... Got out to the water and didn't have a single tool to work on it with. pack it up head back to get the tools then back out to the water to start over... After all that things went better, did some adjusting on the power down angle, the angle of steering where the power is cut to keep from tipping the Kayak excessively, opened up the steering angle where full power is available, also increased the power level at full turn to where it will just spin in place, should be nice for maneuvering in tight places. We,re still going to open up the full power steering window more, I also need to scrap the servo saver on the steering as it is very vague at the center, I think the mass of the motor unit is to much for the spring loading of the unit so I'm going to change it out for a solid arm and that should tighten up the steering. Unfortunately we didn't get any video of it on the water this time but I have a few pics of the control setup in the Kayak.

This is the seat and mounting bracket, the cleat on the front is for the adjustable foot rest.



and the boss in the kayak to mount it to.


The controls are mounted on a hinge for access to the mounting bolt and the foot rest cleat. Mounting system is just mocked up with plywood now that may change but it's good enough for now.




and in the kayak


Were going to add another boss in the kayak so the seat can move forward up to a foot, when it's under power the back of the kayak is pretty deep in the water so we want to shift the weight forward and see if that helps. this kayak was designed for a second little person in the front, grand kids but the youngest is turning 22 this month so the likelihood of them being in the front is pretty slim lol.

Things left, adding the skeg, shortening the shaft once we get the seat moved and the weight balance set.
More programming of the control system, adding a steering angle indicator to the controls and adding a steering center button to bring the motor back to strait ahead.

Hopefully next time we take it out my son with the good camera can shoot some video.

Maybe the mods can move this thread to the projects area, I think it may have out grown the beginner forum.

Brian


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## bpimm

After the last test session we decided to make a few changes, the steering was sloppy, decided to scrap the servo saver for a solid servo arm, I think the mass of the motor was just to much for the spring loaded arm. I ordered a solid arm with a clamp bolt setup so it will be solid. When it came I discovered that it was a lot thinner than the srevo saver so I had to mill down the servo tray and the servo stand to get it down where it will engage the steering pin.
this is the servo saver



and the new servo arm





The other thing we found with this round of testing is we had the motor current limit set a 25A as well as the battery current limit which limited us to 6A out of the battery but even at 6A battery current and 25A motor current the 2 run speed test, 2 runs to average because of current and wind, it averaged 4.5 MPH on the GPS which is actually plenty fast. We also moved the seat forward about 8" which seemed to help the weight distribution, the back of the kayak is riding much higher now. I'll put links to the cell phone video we shot, not as good as my sons camera but it works.

My brother made some programming changes as well, the servo didn't have enough power to hold the steering centered when the motor was in the raised position so he changed things around so when you hit the switch to raise the motor it shuts off the motor drive, turns the motor full left then disables the servo and raises the motor. When you hit the down switch it lovers the motor then enables the servo and turns the motor to strait ahead, this should lessen the strain on the servo. He also added a return to strait push button so when you are turning and approach the heading you want it's one button push to return to strait which helps because there is no steering angle indicator so you don't know where the motor is pointing.

I think I'll get going on the Skeg to protect the prop, and Gary is going to work on some form of trim to fine set the strait ahead position and that should pretty much finish up the project.

Video links
showing the lift command turning the motor off, turning left and raising

maneuverability test


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## francist

That is truly impressive, very nice! The train horn is a nice touch too 

-frank


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## rwm

That is really awesome. Good work.

Robert


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