1/6/2020: added 3 more props for testing left handed prop versions. 3 and 4 blade versions.
1/5/2020: added a experimental 3 Blade Prop.
10/15/19: fixed thingiverse error it messed up the upload of the rubber gasket pdf file
10/14/19: corrected "Middle_Haul_2_V1.5" to "Middle_Haul_2_V1.6"
i tested the new joint between "Middle_Haul_2_V1.6" and Motor_holder_Haul_3_V1.5.stl
with a 3d print test and the joint is correct now.
you only need to reprint "Middle_Haul_2_V1.6" and should be good to go.
10/13/19: working on Errors in haul, was caused by my merging of my design with original authors STEP files.
10/2/19: releasing the updates. all called V1.5
the design changes.
i tried to keep all the tweaks small in keeping with the original design.
during testing the cooling system starts to cycle around 1/8-1/4 throttle so keep this in mind if you are going very slow for long periods of time.
rotated everything to print bed how i print it.
Top lid now has a flat area all around so you can get a nice waterproof seal used with a rubber gasket cut from some 1/16" rubber sheet i got off amazon
Top lid has thickened areas for the bolt hardware.
- The lid now uses threaded inserts 3mm Pem Press-in Threaded Inserts, Flange-Head - Metric, PFLB-M3-2
this allows the lid to be removed and installed over and over with much less damage over time.
- the haul of the boat is updated with a thicker upper lip to again help with the new deck lid and allows the install of the threaded inserts.
the inserts are designed to be Pressed in from the inside out. so the lip of the insert is facing down. they are designed to be pressed in by hand so they are on the loose side. put a little CA glue in the holes then press fit the inserts. thread a 3mm bolt into the insert to spread the fingers as the glue dries.
the servo mount has been changed to use a standard futaba 3003 style servo and the hardware listed below. the servo now mounts from the side rather then top it is harder to install the mounting hardware this way but you get a cleaner shot for the control hardware to the rudder.
optional cooling system added to rear haul. i listed the fitting below
stuffing box area has been added. you will need a 3mmx3mm grub screw to close the new hole. i use a needle with dielectric grease to force grease into the stuffing box under pressure. the tolerances are pretty tight on purpose so be aware you may need to make slight changes during assembly test fit and change as needed.
- the rear haul is the only part of the boat requiring supports you may want to add your own slicer rules when printing. for example I added rules to increase infill to 100% around the prop shaft bushings and where the cooling system inlet and outlet are located also around the motor mount i increased infill to 100%. the reason the rear haul needs supports is because of the servo mount.
I used 20% infill with 3 perimeters for most of the jet boat. 100% infill was used for the rudder and the outter cone of the jet. propeller is 100% infill will Nylon 910 the rest is PLA but you can use asa, Abs, Petg, Etc. .2mm res.
propeller will need supports if you use Nylon due to warping.
exterior Jet housing had been beefed up there was thin wall issues with the housing areas have been beefed up and enlarged. the rear bushing no longer needs a support in slicer.
- there is still going to be a lot of fabrication needed to complete this as everyone is going to use the hardware they come across and have access to.
my prop shaft and prop design are based on using.
you will need some spacer tubes/ bushing retainers that go over the prop shaft they keep the shaft from walking around fore and aft, i made them from some K&N ABS tubing that fits over the 4mm prop shaft
your design can vary depending on the hardware used.
put you can start with one tube at 51.5mm and the other at 15mm
there is one 4mm ID collar used infront of the propeller to hold it in place then the K&N tube spacer goes in front of that. the prop shaft will need to have reliefs cut to hold grub screws depending on your hardware used and your printers calibration and extrusion multiplier. everyones prop shaft is most likely going to be a little different.
*in dealing with some extra heat issues and PLA. the rear of the motor can turn into a heat blast furnace even with water cooling. PLA has a very low soften point so i added some heat shielding to my deck lid because i had one melt a little on me.
*i'm sure i'm forgetting something if i remember i'll add it.
Good luck you should be able to make a very functional jet boat from this.
my testing is unfortunately done for the season so i might learn more lessons next summer when i have a chance to really drive my re-visions and there could be more changes in the future.
Make sure you use all Stainless steel hardware. replace all grub screws with stainless versions. if you just use normal steel hardware it will rot out pretty much overnight. running in a pool the chlorine in the water eats normal steel very quickly.
10/1/19: added PDF files for Decal and Rubber Gasket Patterns for cutout from 1/16" rubber sheet 12x14" and Vinyl exterior Decal sheets.
working prototype #2 is out and i'm making some additional changes.
9/29/19: making progress the bushings are working out.
uxcell Bearing Sleeve 4mm Bore x 8mm OD x 6mm Length Self-Lubricating Sintered Bronze Bushings 10Pcs
I am working these into the new haul version slowly.
i have a created a stuffing box for the prop shaft now as well. this will allow you to force silicon lubricant between the bushings around the prop shaft the stuffing box is sealed with a single 3mmx3mm Grub screw. you open the stuffing box every few runs and using a Medical injector which you fill with grease you fill the box and then recap the plug hole with the grub screw.
I fixed some Thin Wall issues in the original design as well for a cleaner print.
see new prototype photo of Red Haul section.
slowly i'm integrating the released STEP files into the redesign.
9/18/19: well i have not received parts i ordered for the new prop shaft bushings. The Pool is closed for the season so i will not be able to test my new boat edits until next spring.
i started this project back in July and it just took so long to get enough of the boat together for the first test. really frustrating.
the release of the Step files complicated things as well because at some point i will have to go back and redo all my changes in the step file basically start over again.
everything is going to take much longer then i expected and fall is here.
9/13/19: Waiting on some parts before i make more changes.
Currently deciding on which direction to go with the prop shaft bearings.
I ran my first version of the jet boat in a pool and the chlorine ate everything not stainless steel.
a new lid design will use threaded insert nuts so it can be removed and installed over and over without stripping out the plastic. tweaks to the servo mount (standard futaba 3003) adding ribbing to the bellows rubber seal for the rudder shaft. decreased the shaft to haul clearance to reduce the amount of water that can get between the bushings or bearings on the prop shaft. possible more changes as i see them. experimented with 3d printing decals for the haul but the print time becomes over 48 hours so i abandoned them. will upload a template for the window decals once i finalize the fitment.
Battery: right now i'm using a LIPO Shorty pack. 7.4-7.6V with a 100C continuous rating and 200C burst. I tried a 65C/130C pack for my first testing and i Puffed the battery BADLY! i also used a 70A marine ESC and it smoked even with water cooling. i'm upping to a Dynamite 120Amp marine ESC with water cooling for the next tests.
so test 1 was: MagiDeal 2598 4200KV Brushless Motor & Waterproof 70A ESC
test 2 will be : Dynamite 120A BL Marine ESC 2-6S Single Connector, DYNM3876
LIPO test 1: Turnigy Nano-tech Shorty 4200mah 2S2P 65~130C
LIPO test 2: GNB RC Battery 7.6V 5600mAh Shorty 2S LiPo LiHV Battery 100C~200C
Lipo shorties are nice since they are smaller and you can move them around to get better weight changes. i found even at lower voltage the boat is pretty fast.
Slicer Output recommendations:
I printed most of the parts at 3 perimeters and default infills of 15% Grid pattern, honeycomb would be stronger. i found 4 perimeters made the boat a bit on the heavy side.
PLA or PETG. ASA is good stuff because it is waterproof but the colors are limited.
i was most concerned trying to make everything watertight even with defects in printing.
the only parts that will need supports is the prop and the rear Haul because of the servo mount with top 90 degree overhang.
Print the prop at 100% infill recommend Nylon 910 material you will need full supports and clean up will be a horrible pain but its the only way to keep the nylon from curling and ruining the print.
in the future i will rotate the parts for the bed.
explanation of edits:
changes to TOP lid, flattened the mating surface all around the lid allowing for a better seal. Thickened up the areas around the bolt holes to avoid areas too thin to print allowing gaps for water to enter.
i'm using a flat rubber gasket for the deck lid seal cut from some 2MM rubber sheet.
Changes to rear of Haul. changed servo position for better direct drive 11MM rubber seal for rod bellows, allowing for this style of linkage
this new design has a Cooling system integrated to will need 6mm x 19 fittings.
changes to Rear rudder housing. I thickened up the control arm slightly for the 3mm hardware on the new linkage.
Prop changes, changed the mounting design to use a special locking collar included with this 4mm shaft.
Keep in mind the Shaft needs to be modified to work in the jet boat. i turned it around cut off the threaded end, used the locking collar in the rear with spacing to allow for the rear bearing support, there is a bearing shim between the collar and the rear bearing so it spins easy. the prop is pushed on locking the rear to the locking collar then a second collar is installed in front of the prop to keep it from walking forward off the locking collar.
a tube is installed from the front collar to the middle bearing, then the top bearing and another tube installed to the universal shaft. this keeps the prop from rocking fore and aft and holds the bearings into the haul. notches are made in the 4mm prop shaft to lock the 3mm grub screws to the shaft and thread lock is also used to hold everything together.
the clearance was increased so the prop fits easier in the tunnel.
Based on testing there will be additional edits in the future.
usually you create a internal sealed radio box for a boat and the lid is held on with a rubber band more for show. in this case the haul of the boat is the radio box so you need a good lid where you can remove it and install it constantly.