Tuesday, March 3, 2015

V2 fan hub assembly explained

Here's an e-mail thread I thought would be a good topic to share with others:

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Hi Allen,

Last time I emailed you, I was 80% complete in a few months, I’m getting a little closer now.

I’m working on the fan, Sheet #35. Because there are no assembly drawings on many of the subassemblies, it makes things interesting, like a puzzle. The fan hub takes a .156 x .312 flanged support bearing for the Fan Shaft. But where does the other bearing go. (a shaft needs two support bearings). I assume it goes in the Fan Belt pulley. But in you kit of bearings there is no bearing that size.

As always thank for your help.

Ernie

From South Florida: Weather report for today - 81 degrees

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Hello Ernie,

Hey - no fair bragging about your weather!

After some study and speaking as an amateur, here's what it looks like to me:

1. Insert a .156 ID x .312 OD x .125 flanged bearing, flanged side out, all the way onto the Fan Shaft.
2. Insert the Fan Hub into onto the Fan Shaft, narrow end attached to the bearing from step 1.
3. Insert the second .156 ID x .312 x .125 flanged bearing on the Fan Shaft, flanged side out.
4. Insert the Fan Belt Pulley onto the narrow end of the Fan Hub.
5. Attach the Fan Mounting Bracket on the remaining exposed end of the Fan Shaft.

See if that makes sense to you.

Allen

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Allen

That cleared it up.  In summary there is a ball bearing inserted on each end of the Fan Hub. But, why is there a .500 dia x .190 dp cut out in the Fan Belt pulley. I think it would have made more sense to put the other ball bearing in the Fan Belt Pulley. 

One more thing, the gears. Cutting gears is expensive due to the cost of the gear cutters and a rotary table. The gears can be purchased from SDP or other gear houses, expensive. However, I purchased then on eBay for about $3.00/gear. Only slight modification is needed. If you would like more info just ask me. You may want to pass it off to others.

I certainly appreciate the help, thank you again.

Ernie

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Yeah, I wondered about that deep cut on the Fan Belt Pully.  I can only guess that Dad did not think it needed all of that bearing surface contact, and also makes it easier to disassemble should the need arise.  He knew he would have to disassemble the engine after he built it to draw up the plans (contrary to typical product development, Dad built his engines first, then developed the plans after!)

Send some of that sunshine and warm air up here.  We could use it!

Allen

Friday, December 19, 2014

V4 Water Pump Q&A w/Dave Sage

Date: Dec 19, 2014
Re: magnetic drive water pump:

I have a question for those who have built the magnetic drive water pump.
Have you checked the operation of your water pump and confirmed it is moving water? Perhaps did you happen to check it off the engine.

 I built the pump for my V8 version of the V4 several years ago and I'm pretty sure I saw it moving water - at least a few bubbles went by in my clear hose. Now I'm not so sure it's working - or ever worked properly.

 I took it off the engine and cleaned it up and tested it off the engine and sure enough it doesn't pump. The magnetic coupling is not the issue the impeller is moving and you can tell when the magnets "cog" when they slip.

 I recently needed another pump for a new engine so I built a slightly larger version with a direct drive shaft and made (what I think) is a better impeller. But still no pumping action.

 I looked at pictures of some others that people have built and best I can tell they look like mine and appear to be what's in the drawings so I don't think I interpreted anything wrong. I'm not sure why it doesn't pump.

 I'm very interested to know if there might be something wrong with the design although if Jerry made it probably worked. So it's probably something I've done wrong (twice).

 Has anyone else made one of the pumps and actually confirmed operation.

Thanks

Sage

--------------------------------------- Dec 22, 2014

I think I figured out my problem. Off the engine I'm turning the pump too slow. I was using my battery drill which only turns 580rpm. I put it on my AC drill and at 2800 rpm it pumps fine. I think on the engine it probably turns at least 1000rpm. All I have to do is get it primed properly on the engine.

Sage

-------------------------------------- Jan 7, 2015

I found that as the pump is designed does not provide adequate magnetic coupling for the torque required and looses magnetic lock at normal operating speed when pumping 50/50 ethylene glycol coolant.  The torque requirement of a centrifugal pump increases with RPM.  This being said, I found a solution that worked well for me that did not require remaking the pump. I added another set of magnets to the drive, placed between the original set of magnets. The second set of magnets were placed with their magnet polarity opposite that of the first set.  This provided far greater magnetic coupling and holds thru out the operating RPM.  Also it should be noted that once magnetic lock is broken no torque is transferred and the pump comes to a stop and no coolant is pumped. Magnetic coupling can not then be restored without coming to a complete stop and restarted.    thank you,  Wayne Dellinger  717-244-8886



Tuesday, December 16, 2014

V2 crankshaft and tailshaft bearing placement confusion resolved

Q&A e-mails with Ernie (Q) from South Florida and me (A):

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Q: Sheet #22, Crankshaft – The bearing diameter portions of the shaft as noted on the drawing are .500” & .437”.  However, the bearing used on the shaft have inside diameters of .500 which is OK, but the other is (supplied by you) 12mm. However, 12mm = .472”, therefore, the .437” shown on the drawing must be wrong; it should be .472” or 12mm.  The bearing supplied is 12mm ID x 21mm OD x 5mm thick.

A: The crankshaft in the V2 is not like a traditional one-piece crankshaft where you have two ends with the connecting rod throw in the middle.   Basically, this shaft has just ONE end.  On the other side of the crankdisk is the tailshaft.  Both crankshaft bearings are mounted to the crankshaft, but on the SAME side of the crankdisk.  See the crankshaft housing on page 13.  Both crankshaft bearings fit in the housing, and the crankshaft slides into BOTH bearings.

The other side of the crankdisk is the tailshaft (Pg 10), supported by two bearings, with the inner tailshaft receiving the 12mm x 21mm x 5mm bearing, and the outer tailshaft will receive the .250 ID x .500 OD x .187 bearing.

Q: Look on page #18, the figure in the upper left. Note the tailshaft (it is .375” dia.) The ball bearing is 12mm ID x 21mm OD x 5mm thick.  12mm is .472”.  How does a .472 dia. bearing fit a .375 dia. shaft?

A: Both crankshaft bearings are .500 ID, and they BOTH slide onto the .500 diameter section of the crankshaft as illustrated at the top of page 22.

The 12mm ID x 21mm OD by 5mm bearing is NOT mounted on the tailshaft, but rather, it is mounted on the Tailshaft Crankdisk, bottom right on Pg 22 (thus the .472), and the tailshaft is inserted into the crankdisk (thus the .375 ream).

Thursday, November 20, 2014

Tuesday, October 7, 2014

Beamer stops after 5 minutes...

Here's an e-mail I received from Gary Nelson in Oct 2014.  Since I am not a builder (I am a database programmer/analyst by trade), I asked Dana Hall, an expert builder in Florida, if he could help Gary out:

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Allen,
I built  a Beamer engine a few years ago and couldn't get it to run more than a few minutes. I recently tackled it again by making new flywheel out of aluminum with a brass outside ring about 3/8 thick thinking with more mass on the outside of the flywheel I would get better action. It didn't help. I am using the JEH mini propane burner as a heat source. When cold the engine is very free wheeling. How much temperature difference should there be between the stainless cap and the back of the cylinder to keep it running. I am using an infrared thermometer to check temperatures of the cap and the cylinder. Without the fan belt attached it will run when the cap reaches about 100 deg. and the cylinder is 70 degrees. It runs for about five minutes and then slowly stops as the cylinder heats up to about 75 deg.
Any suggestions would be appreciated.

Thanks,
Gary Nelson

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Hello Gary...
Dana Hall here in central florida...
I built Jerry's Beamer engine several years ago now and here is what I have found with regards to Stirling engines...
In Jerry's notes under Stirling engines, there are only 3 things that can keep a Stirling engine from running properly...
1. The cylinders must be air tight with no air leaks...
2. Excessive friction will stop a Stirling engine from running...
3. The timing of the displacer piston with regards to the power piston movement must be correct...

When I built Jerry's Mizer engine I had a problem getting it to run properly until I removed an air leak that I had on the engine... After that everything was fine... But it took time to find it... Stirling engines produce very little power,so everything has to be just right...

I never measured the temperature differences from one end to the other,,, But with the fan running on the Beamer engine, that should help to keep the engine running for quite some time...

I also found that it takes a very small flame to get the engine to run... Sometimes too large or too hot of a flame is detrimental  and ends up heating both ends of the engine... Also the use of stainless steal at the heating end is quite important... Stainless steal does not allow the transmission of heat to other parts of the engine...

Not sure if any of what I have said here will help you, but don't give up on the engine... The Beamer engine with all the bearings in it is a really beautiful smooth running engine...

Any other questions yo may have, please ask...

Dana Hall in Florida

Thursday, July 24, 2014

TIM-6 used in 9 cyl model aircraft engine

Here's an e-mail I received from Andy Johnston on July 24, 2014:

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Dear Sirs,
Since early 2008 I have been using a Jerry E Howell TIM-6 ignition system on my home build Bentley BR2 nine-cylinder rotary engine which I fly in a scratch built 27% scale Avro 504K with great success.

...

Click on the link below to see my five and a half-year project in the air during its third season of public show flying

http://www.youtube.com/watch?v=QoCjro11ZQ0

Kind regards,

Andy Johnston

Thursday, July 17, 2014

Vickie plan alternatives/improvements

Here's an e-mail I received from George Waterman on July 17, 2014.

Please note: Dad sold these plans for 15+ years before he passed away, and dozens (hundreds?) of Vickie engines were built.  Being a perfectionist, I'm sure he would have fixed any errors reported.   This e-mail is posted to offer a different perspective and solutions to the author's understanding of the plans:

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My modifications are either to fix simple errors, or to suggest ways to make the design work better – I will list here the ones I should be able to send in a form that can be understood.

1.       The little lubricator that fits under the slide rail of the crosshead is too big in diameter and height – my little layout that shows the problem and my modified design. See the attached sketch in both JPG and DRW formats “Small Lubricator for Displacer rod end”.  The other rod ends could be made to the original design but I made them like this (except 0.150 high) so they would look similar.  You can decide for yourself.

2.       The rear cap for the displacer has serious problems with staying aligned with the rod.  With Jerry’s design the displacer tilts at an angle and scrapes the bore when the thread is tightened.  I designed three improved versions. The Mod 1 seemed logical but still allowed too much flex.  Mod 2 with the threads also tilted too much when the threads were tightened so I reamed out the threads and made it a press fit with the rod – this is the version in my Vickie now.  I designed the Mod 3 as what I would do if I were making it again – it’s the one I recommend but I haven’t make it yet.   In all cases the rod need to be extended as appropriate to fit the modified rear cap selected. Note also JPG and DRW’s attached for each.

3.       When Installing the rod into the crosshead, it seemed risky to try to machine them as an assembly so I drilled the crosshead for a #2-56 setscrew which allows final fine tuning of the length if necessary.  Jerry’s method would also work if you can do the drilling as an assembly – I didn’t think I could.

4.       When I made the hot cap, I machined it from a single piece of stainless steel – to avoid the brazing operation – I used 304 stainless but it is a bit “gummy” to machine so I would use 303 stainless next time – free machining type.

5.        Also important – on sheet #18 the instructions for the crosshead say machine to 0.5 “ dia – this is too small, causes the sides to be too short.  The diameter should be at least 0.576” diameter to allow full sides.  See attached study sketch “Crosshead 0.5 vs 0.576 study” in JPG and DRW formats.

Good Luck with your model

George Waterman