rythmnbls
Veteran Member
Joined: August 2011
Posts: 145
|
Post by rythmnbls on Jun 10, 2012 17:52:30 GMT -5
Except for balancing the engine is finished. Photo of the all the parts. Photos of the assembled turbine. The question now is balancing, building a dynamic balancer is a project in itself, so I'm tempted just to statically balance it for initial testing, I'm keen to see it run ;D Steve.
|
|
|
Post by racket on Jun 10, 2012 17:56:39 GMT -5
Hi Steve
LOL..................we can all relate to that feeling ;-)
Nicely finished bits and pieces
Cheers John
|
|
|
Post by Johansson on Jun 11, 2012 0:17:56 GMT -5
Very nice work Steve, impressive!
|
|
wolfdragon
Senior Member
Joined: April 2011
Posts: 287
|
Post by wolfdragon on Jun 11, 2012 17:39:44 GMT -5
A turbo rebuild shop should have a dynamic balancer, as long as you can send them the rotation assembly in an assembled form, you should be able to get them to balance it for 50-75 USD
|
|
|
Post by Richard OConnell on Jun 11, 2012 21:09:02 GMT -5
very nice
|
|
rythmnbls
Veteran Member
Joined: August 2011
Posts: 145
|
Post by rythmnbls on Jun 16, 2012 15:29:06 GMT -5
I ran the engine for the first time today, not a lot to report, this was just a propane run. The engine self sustained at 10K, which I'm happy with. Unfortunately my propane regulator wont allow higher speeds so faster runs will have to wait till I'm ready for a kerosene fueled run. Here is a very brief clip of the run, you can hear the engine flame out when I accidentally cut off the propane. You can see the NGV is glowing a bit, at 10K rpm there's probably not enough airflow to cool it adequately. s87.photobucket.com/albums/k142/madluther/Turbine%202/?action=view¤t=100_1073.mp4There was some slight distortion of the NGV during cool-down which caused the turbine wheel to rub, a couple of minutes in the lathe took care of it. Photo of the combustion chamber after the run. A photo of the rear end after reassembly Mechanically it looks good so I hope to post a video of it running on kero soon. Regards. Steve
|
|
|
Post by Johansson on Jun 19, 2012 13:33:56 GMT -5
Congrats on a successful first start! Can´t wait to see a full run on kero.
|
|
rythmnbls
Veteran Member
Joined: August 2011
Posts: 145
|
Post by rythmnbls on Jul 22, 2012 9:30:05 GMT -5
Testing the engine is progressing, had a few problems with the RPM sensor which are now sorted. Here's a few photos of the test setup. Front view.. The rear.. The "dash" A clip of yesterday's run, ran it up to ~34K, let it sit for a bit and then shut it down. s87.photobucket.com/albums/k142/madluther/Turbine%202/?action=view¤t=100_1125.mp4Its a thirsty little bugger, before and after shots of the 500cc / 16oz fuel tank. The CC still needs a bit of work, it seems to burning a bit late and cooking the NGV, watching it in the mirror it looks ok, but in the video you can see its glowing a bit. Other than that the rest of the engine looks pretty good. Steve.
|
|
|
Post by racket on Jul 22, 2012 20:30:17 GMT -5
Hi Steve
34K is kinda slow for a comp that size , you might find that the temperatures and combustion will improve once you're past 40 K , a P2 of 5 psi will have the comp working more efficiently .
LOL, they certainly are thirsty buggers :-)
Cheers John
|
|
rythmnbls
Veteran Member
Joined: August 2011
Posts: 145
|
Post by rythmnbls on Aug 18, 2012 17:51:05 GMT -5
Work on my dynamic balancer is progressing, I finished up the electrics today, and plan on starting mechanical bits tomorrow. Hopefully I'll get the rig finished in time to test it next weekend. Here's a few pics of the electrical bits, the circuit is a Mike Murphy design from the GTBA website. If everything goes to plan I should be able to run the engine up to some speeds that satisfy my adrenaline needs in the near future. ;D Steve.
|
|
rythmnbls
Veteran Member
Joined: August 2011
Posts: 145
|
Post by rythmnbls on Aug 31, 2012 9:37:35 GMT -5
The balancer is finished. I decided not to build a dedicated frame for balancing as the lathe would do the job better than any rig I could build. Here's a pic of the setup. The arms are made of 1.6mm fiberglass with aluminium V sections glued to the ends. A 20mm piezo transducer is glued to one of the arms. Close up of the sensor arm Another shot showing the LEDs used to strobe the imbalance point, a piece of rubber hose has been added to one blade to determine roughly where the LEDs should be. The balancer seems to work quite well, its able to detect very minor weight differences. I was also suprised at how close static balancing was to the mark. I expected the balance to be worse than it was. Regards. Steve.
|
|
|
Post by Johansson on Aug 31, 2012 13:02:21 GMT -5
Nice work! I wish I had the stubbornness to learn electronics, I hate that sheit and a gun at my head wouldn´t inspire me to learn about it. Kudos to you who find it interesting!
|
|
rythmnbls
Veteran Member
Joined: August 2011
Posts: 145
|
Post by rythmnbls on Sept 16, 2012 15:39:24 GMT -5
Now that I have a balanced rotor and decent bearings, test runs at higher RPM are progressing, here is a clip of today's run up to about 45K.
The start was a tad hot as my dremel is getting tired and can only spin the rotor to about 7500 RPM, from there the engine has to accelerate on its own. Other than that, things are looking pretty good.
Regards.
Steve.
|
|
rythmnbls
Veteran Member
Joined: August 2011
Posts: 145
|
Post by rythmnbls on Oct 31, 2012 15:31:06 GMT -5
Been a while since I've updated this due to an unexpected health problem that laid me up for almost a month. One of the main problems I've had with this engine is excessive EGT which has gotten worse over time. It turned out that NGV shrinkage was the culprit. When the engine was first completed the NGV was a firm push fit in the outer case providing a good case to NGV seal. These fabricated stainless steel NGVs tend to shrink a bit during the initial runs and mine was no exception, it has been skimmed a few times in the lathe to fix the loss of clearance between it and the turbine wheel. One side effect of all this shrinkage is the NGV is now a sloppy fit in the outer case, the gap had grown to about 0.25mm, case pressure was down and EGTs were over 720 degrees, not good. The fix was a simple sleeve that fits over the NGV that wedges between the CC and the gap in the outer case. Here's a photo of the sleeve. Another photo showing the sleeve in place. Here's a really blurry clip of the temps at ~50K rpm, which is a big improvement. s87.photobucket.com/albums/k142/madluther/Turbine%202/?action=view¤t=100_1177_zpsb4069840.mp4Plans now are to start increasing RPM by 10K per run, run a tank of fuel through the engine, check everything , rinse repeat, I should also start looking at adding thrust measurement capabilities to the test bench. Thanks for reading. Steve.
|
|
8maddog8
Member
Joined: July 2012
Posts: 24
|
Post by 8maddog8 on Oct 31, 2012 18:30:09 GMT -5
Looking good steve, hope your all better now Would be very interested to see what kind of thrust you will get out of this small bugger
|
|