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Author Topic: XRAD'S HYDROPLANE  (Read 12719 times)

Tombsy

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Re: XRAD'S HYDROPLANE
« Reply #25 on: January 07, 2016, 01:33:07 AM »

Nice work on the strut, the flat bottom will give more lift at the back and help keep the nose down, but easy for you to round it off if you don't need it.
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Brian

xrad

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Re: XRAD'S HYDROPLANE
« Reply #26 on: January 07, 2016, 01:42:23 PM »

Thx!  agree with the flat bottom thoughts. But I have not calculated the fluid dynamics at the strut (and don't plan to) but I  have not decided. Don't know how much turbulence a flat v round bottom would make to the lower half of the prop. I might go for a partial flat bottom (about 1/2 the width of the strut).....

just realized I do not have a motor mount. I was going to machine a mount for the 5 inch rails, but then I found one on line which was at a price that was cheap enough for me not to machine one...
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martno1fan

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Re: XRAD'S HYDROPLANE
« Reply #27 on: January 08, 2016, 06:12:55 AM »

Ive used struts with roller bearings and struts with lead teflon bushes and i have to say i prefer the latter,the roller bearings seem to not hold up as well.What Tombsy said about an s curve is true to some extent but i wouldnt go out of my way to put an s bend in as a gentle curve will suffice,however i would use a teflon liner as i find it works better at the higher rpm than plain brass so long as the liner is glued in if not and it spins it will melt . Also i never use grease i use oil on all my flex shafts ran through an oiler system this is much cleaner than using grease and also better lubrication in my opinion.
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martno1fan

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Re: XRAD'S HYDROPLANE
« Reply #28 on: January 08, 2016, 06:18:40 AM »

I made this mount from carbon kevlar plate i made for my twin 5692 setup thats going in one of my 58 Apaches i produce  :} ,she will run on 10-12 s  :o .
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Tombsy

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Re: XRAD'S HYDROPLANE
« Reply #29 on: January 08, 2016, 04:36:12 PM »

Here's one I came up with for an 1/8 scale '82 Executone I'm building. It has an offset tub so regular rail mounts wouldn't work.The Neu 1527 seem to be the standard motor for racing now on 8-10s.
I'm using both oilers and grease on different boats, the grease is easy to give it a squirt between heats but after a day's racing (4 heats) the flexes are removed and regreased so there is really not much wear. All my boats have the floating brass bushings in the strut and maybe get replaced every couple years.







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Brian

xrad

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Re: XRAD'S HYDROPLANE
« Reply #30 on: January 09, 2016, 02:45:39 AM »

Nice mounts guys. I really like the aluminum one Tombsy. Did you make it? Again, I was going to maching one up, but kenetic racing had just what I needed. 56mm motor mount with 5in rail adapters.


I was able to fit the strut into the lathe and center it offset by only a tiny amount. Angle cut both ends. Looks crooked, but there is more meat at the top of the strut tube for strength... Strut has a blended flat-to-curve bottom. 


under-sized reamed 3/8 and the bearings fit just right, not too tight, not too loose.  Don't want oval bearings....


I like Kenetic racing and offshore electrics. FAST shippers, never get my order wrong..


Waiting on the motor mount before final fitting of shaft tube.  Got two more 1/4 shafts from chinabay, but they only sent the two flex shafts, and not the stuffing tubes(which were supposed to be included) In any case, these flex shafts are the very nice one , stainless, smooth, and the stiff end is very well ground.


I also put up a pic off the net, nasty blenders!


 
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Tombsy

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Re: XRAD'S HYDROPLANE
« Reply #31 on: January 09, 2016, 06:17:27 PM »

Strut looks great, :-))  On my mount I had the ends from a Williams bottom mount and I made the three side pieces. Unfortunately he's not making the mounts anymore they were a great option. Offshore is selling some of the HRC mounts for 5" nitro rails that's a new option as well.
Love Kintec and Offshore fastest delivery ever even up here.
Here's a pic of the Williams mount on a nitro boat I converted where rail mounts wouldn't work easily. The c shaped cap on the end makes motor removal a bit easier.


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Brian

xrad

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Re: XRAD'S HYDROPLANE
« Reply #32 on: January 09, 2016, 08:23:07 PM »

That looks real nice!  What length motor?  I could only find a 75mm long water jacket. With the mount I ordered I may have been able to get another 10mm of cooling....


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xrad

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Re: XRAD'S HYDROPLANE
« Reply #33 on: January 09, 2016, 08:30:55 PM »

As I was typing, the postman ringing with the motor mount from kenetic...nice!
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Tombsy

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Re: XRAD'S HYDROPLANE
« Reply #34 on: January 09, 2016, 10:19:12 PM »

It's 3.25" about 82mm for a Neu 1527 (different wind than the scale boats).
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Brian

xrad

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Re: XRAD'S HYDROPLANE
« Reply #35 on: January 09, 2016, 10:58:17 PM »

Kinetic motor mount kit fit the 5698 nicely.  basic lay-out.  need to re-adjust hull through tube.....
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martno1fan

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Re: XRAD'S HYDROPLANE
« Reply #36 on: January 10, 2016, 10:40:30 AM »

Looks nice,the tube will be easy enough to bend down to meet the motor just be sure to do it with the flex installed so it wont kink,then gentle pressure with your thumb should do the trick.
Mart
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xrad

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Re: XRAD'S HYDROPLANE
« Reply #37 on: January 10, 2016, 08:40:58 PM »

Thanks Martno.

I removed the original strut hull tube by cutting out the epoxy with a dremel.  Placed the motor as low as possible between the 5in rails and at a place where the 1/4 shaft clamp could be removed and to where I felt the best weight placement was.

Then carefully measured for length of new brass tube and cut the brass tube and liner seperately. The best way for me to bend the brass was to take out the hardening by applying a few hundred degrees with my torch. Not to redness, but until the brass tube turns a darker grey and the 'brass' color disappears under heat. Working the torch only over the area to be bent. This was carefully measured beforehand.  There was about 20mm end angle disagreement between original strut tube location and final position, most of which was corrected with a newly placed guide tube.   The only bend to the strut tube was below the hull. It lined up perfectly with the flex shaft centered in the liner.  Turns easily by hand in the tube. And the brass tube is soft enough to re-bend slightly as need..

Next was fixing the guide tube, which I cut from 7/8 stainless pipe; not much more weight than the original alu tube.  Then this was spot fixed to the hull with the clamped drilled plywood, and a few layers of 4oz cloth added to interior. This dried overnight and 2 layers of cloth and more epoxy added to hull bottom to sandwich the stainless guide tube.  The brass tube was located within the guide tube by a bit of clear silicone. There was only a bit of wiggle in the guide tube anyway.

the rear motor mounts used the original location holes(for gas engine).  The front motor mount holes were carefully marked and drilled through with small guide hole, and then enlarged by hand using a pushing cup (grey metal piece at drill butt) and twisting 1/4 turns back and forth. The drill lips will eat away the ply pretty quickly. I also pulled the bit in and out to enlarge the hole vertically to allow for swivel adjustment of the front of the motor, centering the flex shaft better.

Had to cut through to OE battery/servo box to access the hull. Might fix it up later....
Always check and double check position before cutting anything. Makes sure you have enough room to remove the shaft clamp from the motor shaft with everything in place.  Waiting on a 75mm cooling jacket..then it will go together more permanently. Did a test run...pretty smooth. 


vid: https://www.youtube.com/watch?v=6JhzWAE3iWc
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xrad

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Re: XRAD'S HYDROPLANE
« Reply #38 on: January 10, 2016, 11:06:18 PM »

correction to above: should state "Next was fixing the guide tube, which I cut from 7/16 stainless pipe; not much more weight than the original alu tube."
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martno1fan

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Re: XRAD'S HYDROPLANE
« Reply #39 on: January 11, 2016, 11:06:34 AM »

Looking good  :-)) ,never had to heat up a brass tube to bend it yet though  :} .
Mart
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derekwarner

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Re: XRAD'S HYDROPLANE
« Reply #40 on: January 11, 2016, 11:52:09 AM »

Well....xrad says...."and the brass tube is soft enough to re-bend slightly as need..".. & mart says..."never had to heat up a brass tube to bend it yet though"   :o

You guys must have a different brass tube supplier over K&S Products....dam fine toleranced & drawn tubes :-))....but the brass always needs the red flame to anneal it  O0  ........ Derek

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Derek Warner

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xrad

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Re: XRAD'S HYDROPLANE
« Reply #41 on: January 11, 2016, 12:30:15 PM »

What's up Derek!  How is the steam side going?

Martno: You are correct, you don't have to heat it up....but I did not want to kink to only 11/32 brass tube I had...
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martno1fan

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Re: XRAD'S HYDROPLANE
« Reply #42 on: January 11, 2016, 03:03:07 PM »

The worse thing you can do is to anneal a brass tube it then becomes hard and can crack and split over time, leave it alone it bends easy between thumb and fingers never kinked one yet either always leave the flex inside and bend away no issues ever here.Dereck you will find that K&S dont usually do brass in the lengths we need either its all too short in my experience.Shortest tubes i need for petrol or large electric boats is around 18" longest is 31" and K&S dont do either that ive ever found anyway.
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xrad

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Re: XRAD'S HYDROPLANE
« Reply #43 on: January 11, 2016, 03:45:55 PM »

It's not the worst thing you can do.... It will be fine. gentle heat...
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martno1fan

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Re: XRAD'S HYDROPLANE
« Reply #44 on: January 11, 2016, 06:19:07 PM »

Gentle heat will be fine but Annealing wont in my experience ,seen tubes crack and split due to this process even had it happen to me on a tube someone else annealed,obviously got it too hot and bingo ripped the whole driveline out of the boat when it failed and the flex caught in it and snapped but not before ripping the t bar out and damaging my strut,not least i also lost my pop.Id say thats the worst thing that can happen to any prop tube  :o ,but never mind ill leave you to it.
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xrad

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Re: XRAD'S HYDROPLANE
« Reply #45 on: January 15, 2016, 02:17:01 PM »

Made a heat sink for the Beast. The bottom of the Beast is machined smooth with a fly-cutter and there is heat transfer paste between the esc and the sink.  Heat sink is 1/2 thick alu with water/air cooling. Machined up the 1/4 x 40 water fittings and plug. Fittings/Flow can be changed to suit esc placement in hull. Here is also a pic of the 20$ topflight magnetic propeller balancer. Works great.





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xrad

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Re: XRAD'S HYDROPLANE
« Reply #46 on: January 16, 2016, 08:48:34 PM »

7 degree brass cone machined. There was a 1mm or less gap at the front of the strut with the brass tube. But big enough to let water into bearing area and likely up the flex tube This should deflect most of the water before the strut... Fits real snug, bored to .354in
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xrad

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Re: XRAD'S HYDROPLANE
« Reply #47 on: April 17, 2016, 07:57:56 PM »

vid at the lake using 70mm 2 blade prop.  Balance was VERY good. Batteries all the way up front. Turning limited. will add turn fin soon.  Had an issue with the ESC. seemed great for a few minutes, then slowed to about 3/5th of initial speed.  And then it would intermittently cut out.  I think the motor draw was too much...may have to consider another speed control....need more juice to motor. Also, tried smaller 3 blade prop,  it did not seem to work as well, but  with the esc issues, hard to tell.

Did GPS, and she came in at ~60kph at slower speed and she definitely was NOT on plane. Video is at higher speed. Plenty more can be had...this was first run.

https://www.youtube.com/watch?v=2aNu2m06npA


Here is stock 26cc motor for comparison:
https://www.youtube.com/watch?v=QNJdBwUZU-E


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xrad

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Re: XRAD'S HYDROPLANE
« Reply #48 on: April 18, 2016, 12:58:07 AM »

After thinking about it for a bit, I think it was the batteries. 4s lipo 5200mah, but they are only 35c max discharge.  They were in need of a decent charge following about 10 min run time.  Boat was slower after 5min.


So I ordered x2 4s 5000mah 100c Venom packs...see what happens. If it is the esc, I also ordered a 400amp 3-16s water cooled esc.  This needed a turnigy ubec added on for 10$ to run the new metal gear high torque servo for rudder.


Will start with the batteries and go from there. As far as props, the stock aluminum 1.4x78 (x478) was good. will try a 1.6 x 78 (x678). also will try an octura (x482).


If it is just the batteries, may have to build another boat with the extras!
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xrad

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Re: XRAD'S HYDROPLANE
« Reply #49 on: April 19, 2016, 02:58:48 AM »

Theoretical thoughts: So with 100c 5000mah...should be 500 amp max output/200amp max motor draw ~2.5min run time...x2 for 2 batteries =~ 5min run time max. Trying to keep the weight down. Could run 8s2p for longer run times,  slower top end...


Original batteries were ~5000mah 8s 35c which gave about 1.5 min of full power..which is just a bit more than what I got in real life....

Using a 78mm 1.6 pitch prop =~ 124mm x 25000rpm  w/20% slip =~ 90mph in a perfect world.  Minus factors: boat mass, water resistance, wind, heat, resistance....suspect I should see about 65mph..which would be nice...


Boat is heavy fully loaded..have to weigh it...

thoughts??
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