Done lurking

[DavesWimshurst]

Hi,
I'm an exhibit designer/builder/repairman for a small science museum in Aurora Il. I got my first lathe in the mid 60's. I thought I'd post a few pics on topics I've seen here.

Some engines

a radius tool

an LTD Stirling engine

some turner's cubes, the largest is 2 inch.

More later

Dave

 

[mklotz]

What, no Wimshurst machine?

Welcome aboard. You've got some lovely models there.

BTW, you have my retirement dream job.

 

[Metal Butcher]

Welcome to the forum Dave!

Lurking is simply casual obsevation prior to becoming an active member.

I'm sure most of the active members started out this way.

I look forward to see more pictures of your work.

Question. What is that small motor in front of what appears to be a Stuart?

I like small, simple, and interesting motors. Any chance you have a larger picture of it?

Thanks.

-MB

 

[DavesWimshurst]

Ok

Sectorless triplex Wimshurst machine with 18 inch disk.

Will try to decipher posting vids next
Dave

 

[DavesWimshurst]

MB
The small bronze engine in front of the Stuart 10V is a piston valve of about 3/8 in bore and stroke.
I think I found the plans in an old model magazine from the 30's. I had access to a large library when in grad school. For the record it never ran well if at all, but it looked cute for the pic.

Marv
Sometimes the visitors, mainly school children, try to destroy/eat the exhibits. Grew up on a pig farm, same problem.

Dave

 

[DavesWimshurst]

Video

http://s596.photobucket.com/albums/...cs/?action=view&current=WimshurstDemover3.flv


Dave

 

[cfellows]

Welcome to the Forum, Dave.

Nice Wimshurst machine. Always wanted to build one but haven't yet. I do have a Van De Graaf generator that I built. I made a spun copper high voltage terminal for it. It's more or less an oblate spheroid that's 6" inches thick and 9" in diameter. Unfortunately, I've got it packed away since we are trying to sell our house.

Chuck

 

[Maryak]

Dave,

Welcome to our forum.

Best Regards
Bob

 

[ChooChooMike]

Warm welcome Dave & wonderful machines !!!

Mike

 

[seagar]

Welcome Dave and thanks for showing your pics.

Ian (seagar)

 

[steamer]

Welcome!

Dave ( Steamer )

 

[Kermit]

Nice Wimshurst.

What is the peak average voltage on the sparks? and did you have any problems getting the insulators to hold up to that max?



I'm full of questions, but not rude! Welcome aboard Dave
Kermit

 

[rickharris]

Nice Wimshurst.

What is the peak average voltage on the sparks? and did you have any problems getting the insulators to hold up to that max?



I'm full of questions, but not rude! Welcome aboard Dave
Kermit

It takes about 10,000 volts to jump an inch of dry air!!! Current is low though.

 

[DavesWimshurst]

Kermit,
I've not measured voltage on this machine but it's near 200 kv in dry weather. A larger machine with 23 inch disks was measured at over 300 kv by using 10 inch diameter spheres as a spark gap and referring to a table in physics handbook (CRC handbook). Spark length depends highly on size of the balls in the gap. The current level measures about 100 micro amp when measured with an analog micro ammeter in series with a small spark gap.
The disks used are G10 epoxy fiberglass. I've had some G10 that wasn't insulating enough to hold a charge and some that worked very well.
The insulators used to support the charge collectors and the food storage containers used to make the leyden jars are acrylic. All surfaces near high voltage must be kept clean and polished to reduce corona discharge.
Dave

 

[rake60]

Welcome to HMEM Dave.

Rick

 

[90LX_Notch]

Welcome Dave.

What a cool job. It must be a very rewarding one at that.

Bob