Big Linear FWE for a Paying Client

Moderator: Mike Everman

larry cottrill
Posts: 4140
Joined: Sun Oct 05, 2003 1:17 am
Antipspambot question: 0
Location: Mingo, Iowa USA
Contact:

Big Linear FWE for a Paying Client

Post by larry cottrill » Sat Jan 23, 2010 4:37 am

All right, I know -- I haven't piped up for a long time. Lost my "day job" Nov 05, 2009 after 27 years. They just escorted me out with what personal stuff I could carry in both hands, sent the rest to me on a pallet ( ! ) after they cleaned out my desk and cubicle. But, I have been working on this beast, for an industrial client who shall remain nameless, for now. This is not flight capable -- real industrial strength construction, "for shop or outdoor use" - ha.

An unfolded FWE, not for propulsion. The client wanted high tail flame temps AND velocities. Exact usage is proprietary, but I'm just calling this an "industrial heating" engine. This is all Type 304 stainless, 2 mm thick. The tailpipe is 4-inch OD sanitary tubing; the intake is 2.5-inch OD, same material. The replaceable section aft of the chamber is not for tuning; it is for the client's experimental work. Steel wire O-rings (not shown here) are used as "gaskets" at the mating flanges under the clamps. This engine is almost 5 ft in length, and weighs in right at 25 lb [EDIT: NOT 40 as originally stated]. All fabrication by Jim Russell and his son Matt, with just a little help from me here and there along the way.

Enjoy!

L Cottrill
Attachments
2010-01-13_001_crop1_small.jpg
Finished front end of basic shell. Perspective exaggerates the
size of the flare, which is 105 mm ID. Flare was hogged out of
Schedule 10 304 SS pipe reducer. Largest chamber ID is almost
200 mm. Photo Copyright 2010 Larry Cottrill
2010-01-13_002_crop1_small.jpg
The finished front end -- intake, chamber with engine mount
"blades" and flange for Tri-Clover style clamp (lying open just
behind). Photo Copyright 2010 Larry Cottrill
2010-01-13_003_crop1_small.jpg
Closeup of the bottom side, showing the engine mount
"blades", mounting points and tubular truss.
Photo Copyright 2010 Larry Cottrill
2010-01-13_004_crop1_small.jpg
Another view of the bottom side.
Photo Copyright 2010 Larry Cottrill
2010-01-13_005_crop1_small.jpg
Completed engine shell, tailpipe fully assembled with steel
O-rings and Tri-Clover clamps in place. Rear left view.
2010-01-13_006_crop1_small.jpg
Completed engine shell, tailpipe fully assembled.
Front left view. Photo Copyright 2010 Larry Cottrill
2010-01-13_007_crop1_small.jpg
Closeup of chamber and replaceable experimental segment.
Photo Copyright 2010 Larry Cottrill
2010-01-13_008_crop1_small.jpg
Closeup of complete engine shell on mounting truss.
Photo Copyright 2010 Larry Cottrill
2010-01-13_009_med.jpg
Complete engine shell on mounting truss. Jim Russell
in the background, working on another project.
Photo Copyright 2010 Larry Cottrill

Mark
Posts: 10727
Joined: Sat Oct 11, 2003 10:14 pm

Re: Big Linear FWE for a Paying Client

Post by Mark » Sat Jan 23, 2010 5:15 am

Welcome back to the Hotel California Larry. I'm curious about your gasket wire, if it is a single strand of stainless steel or several windings. The only thing I have used for my tri clover clamping is a single loop of 1/16 inch copper tubing that fit in the concave groove, unlike the typical teflon gasket that also has a flange that extends both sides of the humped/raised region, well you know what I mean.
Nice looking noise maker, you can build muscles hefting it about. I once attempted an 18 petal valve, 4 inch diameter plumbing pipe pulsejet necking down to just 3 inches, with the head and connnecting bells, the thing weighed 48 pounds. That's some heavy lifting. ha
Presentation is Everything

metiz
Posts: 1517
Joined: Fri Apr 21, 2006 6:34 pm
Antipspambot question: 125
Location: Netherlands

Re: Big Linear FWE for a Paying Client

Post by metiz » Sat Jan 23, 2010 12:23 pm

Hey Larry, sweet looking engine.

I know it's not the purpose of this engine but do you have a thrust reading?
Quantify the world.

Johansson
Posts: 1161
Joined: Sun Nov 21, 2004 9:42 pm
Antipspambot question: 0
Location: Northern Sweden

Re: Big Linear FWE for a Paying Client

Post by Johansson » Sat Jan 23, 2010 5:28 pm

Hi Larry, great to hear from you again!

Great looking engine you´ve got there, any chance of a video of it running later? :wink:

PyroJoe
Posts: 1743
Joined: Wed Aug 29, 2007 5:44 pm
Antipspambot question: 125
Location: Texas

Re: Big Linear FWE for a Paying Client

Post by PyroJoe » Sat Jan 23, 2010 5:47 pm

Very clean project Larry! Good to hear from you, hope this year brings better fortune.
Kindest regards, Joe

larry cottrill
Posts: 4140
Joined: Sun Oct 05, 2003 1:17 am
Antipspambot question: 0
Location: Mingo, Iowa USA
Contact:

Re: Big Linear FWE for a Paying Client

Post by larry cottrill » Sat Jan 23, 2010 10:19 pm

Mark wrote:Welcome back to the Hotel California Larry. I'm curious about your gasket wire ... That's some heavy lifting. ha
Ha - Hotel California, where everyone checks out but nobody can leave. The wire O-rings are just 1/8-inch mild steel filler rod, expertly crafted by Matt Russell for a perfect fit in the groove. I'm hoping the relative softness of the wire will cover any difference in expansion. My "estimate" was WAY off; I must be aging fast -- I weighed her last night (the engine alone) right at 25 lb. I'll have to edit my first post.
metiz wrote:Hey Larry, sweet looking engine.
I know it's not the purpose of this engine but do you have a thrust reading?
Thank you, sir. No, I have no way of measuring thrust for such a beast. I wanted the opposed forces to minimize net thrust that their fixture would have to work against, since it's a portable rig.
Johansson wrote:Great looking engine you´ve got there, any chance of a video of it running later?
Thanks to you, as well. I'll definitely get some video, and stills as well if I can work that in.
PyroJoe wrote:Very clean project Larry! Good to hear from you, hope this year brings better fortune.
Kindest regards, Joe
Thanks very much, Joe! Good to hear from you.

L Cottrill

larry cottrill
Posts: 4140
Joined: Sun Oct 05, 2003 1:17 am
Antipspambot question: 0
Location: Mingo, Iowa USA
Contact:

Some More Details

Post by larry cottrill » Mon Jan 25, 2010 7:06 pm

Here are a few new photos that should clarify some of the details.

The mounting fixture for the starting air and fuel pipes is a chevron shaped flat blade with clamping blocks welded on. All 304 stainless. This would be too bulky and crude for a "moving" engine, but should be fine for a stationary intake. Its worst feature in reality is that the flat blade has to be mounted off-center in the flare (to get the pipes in the center plane), which means it perverts the flow into the flare to some degree. Shouldn't be a big problem, though.

The mounting truss is made up from 1-inch square plain steel tubing, with heavy washers welded on at all mounting points. There are four mounting points for the engine and a triangle of points left over at the front to bolt the truss onto the client's fixture. All 3/8-inch bolts (about 9.5mm). Naturally, I couldn't get the right size AN6 aircraft bolts locally, so I drilled out four standard hardware bolts for cotter keys on Jim's drill press. Some fun, but they work. The sheet aluminum heat shield (maybe 24 ga alloy) is captured between the engine and truss as they're bolted up. This should be a really good mounting setup for the client.

L Cottrill
Attachments
2010-01-20_002_crop1_small.jpg
The mounting fixture for the starting air and fuel pipes. "Crude but effective"
as I always say - perfectly satisfactory for a stationary engine.
Photo Copyright 2010 Larry Cottrill
2010-01-20_003_crop1_small.jpg
Wider view of the finished engine front end with the pipe
mounting fixture in place. Photo Copyright 2010 Larry Cottrill
2010-01-20_005_crop1_small.jpg
Engine mounting truss and sheet aluminum heat shield.
Color of heat shield is false, caused somehow by digital camera
and electronic flash combination. Photo Copyright 2010 Larry Cottrill
2010-01-20_006_crop1_small.jpg
Lower side view showing four bolts through mounting truss into
engine mount points. Heat shield is sandwiched between engine
and truss. Photo Copyright 2010 Larry Cottrill
2010-01-20_007_crop1_small.jpg
Detail shot of engine bolting to mounting truss.
Photo Copyright 2010 Larry Cottrill
2010-01-20_007_crop2_small.jpg
Closeup of engine mounting method: Bolt through mounting truss from
below, lock washer, cotter key inserted through castellated nut and
hand-drilled hole, bent to secure. That should do it.
Photo Copyright 2010 Larry Cottrill

larry cottrill
Posts: 4140
Joined: Sun Oct 05, 2003 1:17 am
Antipspambot question: 0
Location: Mingo, Iowa USA
Contact:

Fuel and Air Pipe Setup

Post by larry cottrill » Tue Jan 26, 2010 3:09 am

Here it is with the starting air (bottom) and fuel (top) pipes clamped in place. Note the black lines on the pipes -- the distance of these lines from the front face of the front clamp = the distance of the business end of the pipes forward of the transition from intake tube to front chamber cone edge, i.e. where the airflow "breaks" into the chamber. As shown, the fuel spouting point is about 1 inch (25mm) forward of the transition, the starting air spouting point about 3 to 4 inches farther out.

The fitting on the fuel pipe is a 3/8-inch "compression" fitting. The hoses I use for fuel delivery have nifty fittings equipped with rubber O-rings that perfectly seat in this type of fitting, without the need for wrench tightening. On the air line, I just leave the standard brake line flared end, which fits the rubber tip of the typical compressed air "blow gun" quite nicely.

L Cottrill
Attachments
2010-01-25_001_crop1_small.JPG
Fuel pipe (top) and starting air pipe (bottom) clamped in place.
Photo Copyright 2010 Larry Cottrill

larry cottrill
Posts: 4140
Joined: Sun Oct 05, 2003 1:17 am
Antipspambot question: 0
Location: Mingo, Iowa USA
Contact:

Experimental Fuel Pipes

Post by larry cottrill » Thu Jan 28, 2010 3:29 am

I finally figured out the 'macro' setting on the new ELF camera my son Jonathan gave us for our anniversary in November. So, here's a shot of the "business end" of two fuel pipes for this engine - in both cases, 3/8-inch steel balls welded into the cut ends of 3/8-inch OD steel brake line.

The left one is intended to provide only moderate turbulence, with very free flowing fuel vapor around the ball. The other one is an attempt to maximize downstream turbulence. This includes creating slight "back pressure" in the line at strong flows, due to the somewhat restricted port area. On that one, the downstream half of the ball was ground off after welding.

I'll talk about these in more detail on the Tools and Construction Forum later.

L Cottrill
Attachments
2010-01-27_003_crop1_small.jpg
Two fuel stingers - Left: Round ball, very free flowing,
moderate turbulence; Right: Half ball, somewhat restricted
flow, high turbulence. Photo Copyright 2010 Larry Cottrill

tufty
Posts: 845
Joined: Wed Dec 24, 2003 12:12 pm
Antipspambot question: 0
Location: France
Contact:

Re: Big Linear FWE for a Paying Client

Post by tufty » Thu Jan 28, 2010 7:38 am

Hey Larry, welcome back.

Beautiful work, as ever.

Sorry to hear about the job loss, that's a hard one to suck up and keep a smile on your face. Tough finding another gig, too, especially once you get beyond 30, and even more so in this "unstable" financial climate. Let's hope this little beauty opens a few doors.

Simon

Jutte
Posts: 332
Joined: Wed Aug 22, 2007 11:01 am
Antipspambot question: 0
Location: NZ

Re: Big Linear FWE for a Paying Client

Post by Jutte » Thu Jan 28, 2010 9:43 am

Hi Larry,
Sorry to hear about the job situation - hope things work out for you.
Praying for you dude.Cool engine...
Jutte

larry cottrill
Posts: 4140
Joined: Sun Oct 05, 2003 1:17 am
Antipspambot question: 0
Location: Mingo, Iowa USA
Contact:

Re: Big Linear FWE for a Paying Client

Post by larry cottrill » Fri Jan 29, 2010 1:27 am

tufty wrote:Hey Larry, welcome back.
Beautiful work, as ever.
Sorry to hear about the job loss, that's a hard one to suck up and keep a smile on your face. Tough finding another gig, too, especially once you get beyond 30, and even more so in this "unstable" financial climate. Let's hope this little beauty opens a few doors.
Simon
Jutte wrote:Hi Larry,
Sorry to hear about the job situation - hope things work out for you.
Praying for you dude.Cool engine...
Thanks, gentlemen! I probably made my situation sound lots worse than it is. I did end up with a good slug of retirement savings, and we qualified for COBRA so our health insurance can continue (with us paying something for it, of course). I sent out resumes for a while, but finally just decided I'd be better off working to do business.

My main difficulty really is that I need to make my corporation pay off, somehow -- which it never has. Even this prototype isn't a money maker. However, if the client's experimentation goes well, we could allegedly end up making these by the hundreds, and I certainly would profit from that. (Actually, my main difficulty is learning to think like a businessman instead of an artist. Now THAT's a tough row to hoe.)

Also, there is nothing "exclusive" about my design for this engine. So, I could offer it for other heating uses, as long as I don't divulge the proprietary nature of what the client is doing with his. We think that if we made a quantity of these (even as few as ten at a time), we could make a profit selling them at somewhere around $2000 US, and possibly much less. That surely can't be too bad for an all stainless engine this size, if it's a good fit for a particular industrial application.

Re-engineering this one for propulsion would not be difficult, either. It could be folded, or a standard sanitary tubing U-bend could make it a sort of "Ecrivesse". Done that way, it would make a nice bike or kart engine. It could be easily re-designed for a conical tailpipe to optimize thrust. "Limited only by your imagination." Ha.

L Cottrill

hagent
Posts: 413
Joined: Sun Feb 06, 2005 9:01 pm
Antipspambot question: 0
Location: Simi Valley CA

Re: Big Linear FWE for a Paying Client

Post by hagent » Wed Feb 03, 2010 7:13 pm

Hi Larry,

Long time no chat.

A very nice build!

Did you get a chance to try the new injectors? I need to make something much better than what I currently have on my large PJ before I fire it up again.

Sorry to hear about your job. I hope you can get that order. It sure is nice to make money at something one loves to do.

Take care,

Hagen
Hagen Tannberg

Irvine.J
Posts: 1063
Joined: Mon Jun 05, 2006 4:28 pm
Antipspambot question: 0
Location: Brisbane, Australia
Contact:

Re: Big Linear FWE for a Paying Client

Post by Irvine.J » Wed Feb 03, 2010 8:22 pm

Badass engine larry, all the best with it I hope it rocks your world :)
James- Image KEEPING IT REAL SINCE 1982
http://pulseairdefence.com
[url=callto://project42labs]Image[/url]

larry cottrill
Posts: 4140
Joined: Sun Oct 05, 2003 1:17 am
Antipspambot question: 0
Location: Mingo, Iowa USA
Contact:

Re: Big Linear FWE for a Paying Client

Post by larry cottrill » Fri Feb 05, 2010 2:06 am

hagent wrote:Hi Larry,
Long time no chat.
A very nice build!
Did you get a chance to try the new injectors? I need to make something much better than what I currently have on my large PJ before I fire it up again.
Thank you, sir. No, haven't run with them. I thought I might be able to test outside today, but by the time I'd made some last minute mods to my aviation grade test stand (a monster treated plank with a slug of joist hangers nailed onto it) to get a better fit of the mounting truss, I was out of time and patience and it seemed pretty cold and windy. Snow tonight (maybe with freezing rain) running into tomorrow, but maybe Saturday will work. The client is mighty eager to know this runs.

I also think I have a problem with propane -- all I still have is just a couple of regular 20 lb cylinders, which I seem to remember somebody said have restrictors in the valves. Apparently, there is a small forklift cylinder available, 30 lb of propane, and no restrictor (obviously, since they have to develop a few HP). So maybe I can get my hands on one of those. The only other thing I could try is tapping into the supply for my Y2K generators. It's one of those big sausages 3 ft diam x about 8 ft long. It's rigged to deliver a sort of 'intermediate' pressure out through 5/16-inch OD copper tubing, and I could probably tap into it there to drive the line regulator / throttle rig I built.

L Cottrill
Attachments
2010-01-28_003_crop1_small.jpg
Regulator and throttle assembly, rear view. See
Tools and Construction Forum for details.
Photo Copyright 2010 Larry Cottrill

Post Reply