"Fat Boy" 12/118 thrust engine

[pitciblackscotland]

Hi John,
I have one of those small electric gear pumps you could use 10 Volts 2.75 GPH @ 60PSI 14 Volts 3.00 GPH @ 90 PSI It work really well for the JFS.

www.youtube.com/watch?v=bi6FamS5aG8

Cheers,
Mark.

[racket]

Hi Mark

LOL, its the main fuel pump that I'm needing 90 psi for , at ~40 GPH flow :-)

Just did some more checking of the starter alignment by trying the alignment tool in the 3 different mounting positions and nothing changed , so it at least is "running true" .

What I did find was, if the starter mounting was rotated relative to the bellmouth it was possible to get all of its feet in contact with the bellmouth at the one time , but in the worst position it had ~0.012 thou - 0.3 mm clearance , so it appears as though the bellmouth lip has a slight wobbly in it making it a tad off square to the alignment tool .

At 0.012" on a ~4 inch radius it only represents a 0.175 of 1 degree misalignment , close enough .............a shim washer between foot and bellmouth will fix that .

On to the next job.

Cheers
John

[smithy1]

Am interested to see your completed starter setup John....I'm still in two or three minds about what I should do with the 6041...I have a couple of electric motors to choose from but am thinking of a sliding motor setup over the bendix type. The bendix would be more simple I guess.

Cheers,
Smithy.

[racket]

Hi Smithy

The main reason I used a sliding type is I don't have a soft start , its max amps from the moment the toggle switch is thrown , the whole start is over with in several seconds , this would place a lot of unwanted force on a bendix as it tries to engage over the nut.

With the sliding type , once the motor is slid forward its a positive engagement , with a hand on the back of the motor ready to disengage in a few seconds time, theres not much that can go wrong.

Cheers
John

[racket]

Hi Smithy

A coupla pics of the mounted motor






LOL, being a cheap arse the starter only costs me $75, second hand 1987-1989 Toyota Camry SV-21 starter , simply cut off the gearbox and solenoid , throw away the gears but retain the solenoid to fire up the starter.

Just need to make the actual connection piece that fits onto the starter gear and goes to the comp nut , I'll have to have the rotor in the engine to get distances , so thats a job for another day .

Cheers
John

[smithy1]

Thanks for the photos,

Hmmm, I might look into a sliding setup for the Beast, I can still "soft start" it though via my 150amp ESC. A 29mm (1-1/8") hex socket mounted on the shaft of the 1717 castle might do the trick nicely....I have roughly machined up a 1/2" square section ring to fit around the snout of the comp housing behind the bell-mouth, I need to split it in half and fit a hinge to one side and a clamp bolt to the other...or two clamp bolts??? Then I will make up 3 parallel struts and mount for the 1717 to sit on and slide back and forth. I might do a rough drawing and see what I can come up with.

Mounting the socket to the 1717 will be a bit of a task...has to be able to handle up to ~30,000rpm, it only has a 5mm shaft..I'm open to ideas.

Cheers,
Smithy.

[racket]

Hi Smithy

With your socket , I'd be inclined to try and make an alloy one , theres very little torque being transmitted so a steel one is gross overkill .

With the 10/98 engines "socket" , the alloy round section was fitted to the chuck in my rotary table on the mill and a central hole was made , then six small "half" rounds were milled on the edge of the central hole to accept the six corners of the 7/16 UNF comp nut .

The hole for the motor shaft was machined prior to the alloy section being put on the mill, or was it at the same time , can't remember .

The size of the comp "nut" on the 6041 does make it a difficult job and probably was in the back of my mind when I decided to stick with a leafblower for it .

My preference for the 6041 would be to remove the comp wheel and machine the snout to take a smaller socket either externally or even internally into that domed snout.

Maybe even a "slot" milled across the centre drill hole that a small flat male piece could fit into , the male piece could be machined up from a ready made 5mm bored "whatever".

Cheers
John

[racket]

Hi Smithy

Decided to checkout some old bits from when I tried Marks starter and found the connector





5mm bore

I'll send it down to you if you'd like it, its of no use to me .

Cheers
John

[smithy1]

Oooh...that looks the ducks nuts right there...I'd really appreciate it if you could shoot it down Sir. Just let me know the cost/postage and I'll sort something out.

Cheers,
Smithy.

[racket]

Hi Smithy

I'll pop it in the post today .

It might give you some ideas at the very least .

I'll send it to Standard Aero ?? ..............still in Sir Thomas Mitchell Rd??

Cheers
John

[smithy1]

Dec 3, 2015 14:47:55 GMT -5 racket said:

Hi Smithy

I'll pop it in the post today .

It might give you some ideas at the very least .

I'll send it to Standard Aero ?? ..............still in Sir Thomas Mitchell Rd??

Cheers
John

Thankyou muchly, really appreciate it.

Hope it does give me an idea or two...I've usually got no idea..

Yes...same old address.

Cheers,
Smithy.

[racket]

Hi Smithy

Its on its way :-)

Cheers
John

[racket]

Hi Guys

The 73mm long coupling for starter made .



The starter rotor was fitted to the lathe chuck and a 6mm threaded hole made in the drive gear axis , a 6 mm cap screw holds the coupling square against the output end bearing , 3 radial grub screws into the gear teeth transmit the torque .



Theres a steel socket fitted into the end of the coupling to fit the 12 point comp nut , 3 further grub screws fitted into indents in the socket OD along with heaps of Loctite on all threads should be sufficient to cope with the torque.

Now its time to put the starter back together .

Cheers
John

[pitciblackscotland]

Hi John,
That coupling looks nice and heavy duty

Cheers,
Mark

[racket]

Hi Mark

It sure is ,....... hopefully everything will align once the engine is assembled, I took the trouble of machining up a mandrill to replicate the starter gear and bolted the connector to that so that I could machine the socket recess true to the gear recess , its as accurate as I can make it , ....................LOL, lets hope the rest of the engine is :-)

Cheers
John