Author Topic: Project Roid  (Read 12486 times)

38ac

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Re: Project Roid
« Reply #15 on: December 22, 2017, 12:16:24 PM »
Glort,  the twins are much harder to get settled down on a cart than a single!! There is nothing inherently smooth about them unless you keep them below about 500 RPM.  Primary reason is the balancing weight is on opposite sides of each flywheel and they are  a Looong ways apart.  An internally balanced 650 RPM twin with no balance weights on the flywheels would be a real nice engine!!  Problem is the dont make one,, that I am aware of. :(
Collector and horder of about anything diesel

2Ton46

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Re: Project Roid
« Reply #16 on: December 22, 2017, 01:40:35 PM »
I agree getting it settled down is a challenge.  I think the primary reason mine is reasonably stable is that it is sitting on a welded cart made of a little over 30 feet of W4 beam and some 1/2" plate, plus some various other structural steel. It probably weighs half as much as the engine or more. Not to mention the almost 3 lbs of lead weights placed on the flywheels to tame it further.  It still vibrates, but reasonably, as in its not self-driving away and its not resonating the radiator supports. Somehow in that video clip it looks way smoother than it really is, part of it is that it is actually running a little slow in that clip, I had failed to get the governor adjustment correctly tight and it crept down a little on me. The other part is the soil is soft under it as we had had a little rain. As far as mobility, I can move it just fine by hand on the concrete shop floor.  Once outside on soft soil or on any sort of grade, its more than I can do alone, so it gets hitched onto something for a tow.

tdupriest

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Re: Project Roid
« Reply #17 on: December 22, 2017, 01:50:07 PM »
Just watched the video.  Nice set-up.
« Last Edit: December 22, 2017, 03:19:41 PM by tdupriest »

2Ton46

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Re: Project Roid
« Reply #18 on: December 25, 2017, 04:38:09 AM »
Have to love the sleeping diesel, seems if everything is right it seems they can sit nearly forever before a call to service. Funny how engines can flock together and take up all the shed space. They seem to do that in a lot of places.

Had some time yesterday and some good weather, so we setup the 'Roid, belted up the yard fan, and hooked up the shaft to the shop fan.  Filled the tank and prepped everything for a good test run.  Let her run from about 10am til just after dark, a touch over 8 hours. Looks like the next event will have at least 8 hours of run time on a tank of fuel, and could stretch probably to 10 hours with careful observation over the last couple of hours. Engine ran without any smoke all day. Everything looks good, although I have a little evidence of slobbering oil on one cylinder. it wasn't much as it never dripped off of the exhaust elbow where it is appearing. Hopefully its still breaking in, and its not that questionable oil ring not doing its job. I'll pull the cover and inspect everything before the next run. Still have a little work to do on the cart setup, and then it will be time for paint.  I can do many things, but painting seems to always drive me crazy. hopefully i can get everything prepped sometime next week if the weather cooperates.

BruceM

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Re: Project Roid
« Reply #19 on: December 25, 2017, 05:35:11 AM »
There's no such thing as a jackhammer CS 6/1, Glort, just a CS that needs some attention.  Quit fiddling and use 38AC's method...if you had trouble adding counterbalance weight equally to both flywheels there's now doubt you have wildly mismatched flywheels and/or offset counterbalance so get them lined up and match'ed up first. 

A "jackhammer" (lots of vertical movement) is clearly grossly underbalanced, so once your wheels match you can start with perhaps 8oz to each wheel added to the counterbalance.  4oz is a modest change, 2 oz for fine tuning.  Back off if you start to see too much fore-aft movement.  When the wheels are matched first, it really is simple.


2Ton46

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Re: Project Roid
« Reply #20 on: December 28, 2017, 01:40:57 AM »
Glort, Hopefully your balance attempt is successful this time.  Without seeing your engine in operation, it's possible that you might have added the weights opposite of where they needed to be, easy to miss and makes a skinny jackrabbit into one that has had a lot of carrots. Sounds like an awesome party either way!

I received my long awaited package today, so was able to install an intake pre-cleaner on the intake and I put a couple of flappy rain-caps up on the exhaust. I'm still tweaking the intake, as it doesn't seem to want to sit level, not that anything else is that perfect on the beast either, but it would look a bit neater. Probably will have to re-bend the support arm to get it to hold everything a bit farther from the side. It has cut down a little on the intake noise and will look classy once leveled up proper. The filter housing is a used one that I had sitting around on the shelf for almost 10 years from an old machine that is no longer around.



I haven't tested the rain-caps under load, but I think I have them balanced properly for the relatively light exhaust flow considering they are 5.5" diameter caps. I'm also not looking for them to be the solution for stormy weather, rather something to keep out a passing shower if I get caught with the thing out of the shed that I don't have to remember to install after shutdown. I can never remember the buckets that I was using.  I have them balanced to just float about 3/4" open with the engine running with no load.  Slowing the engine and then opening the rack will have them stay nearly all the way open, so they should stay somewhere around half open under moderate load. Also, the caps are of the silent type, so that if they start bouncing about they don't make a loud clang noise, just a soft thud as there is a bit of a hard rubber insert that they impact before going metal on metal. Hopefully, I can do a test under load sometime tomorrow and see if they will be as expected. During the brief no-load test run they weren't bouncing, just floating, and were not making any noise that could be heard over the normal engine noise. I also think they will be a nice visual load indicator.



dieselspanner

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Re: Project Roid
« Reply #21 on: December 28, 2017, 10:41:25 AM »
Hi Glort

I think the Kalashnikov principle is the way to go with the linkage. somewhere on here is a photo of a tension device, it's just a piece of 2.5mm welding rod bent into a curve, allowing a light spring to put tension between the first connection and the last. I used the split pin holes to hook the rod and the end of the spring (one from a twin SU carb set up)

It makes a real difference, I get a flutter of just 3/4 rpm under 3/4 load.

After I posted the photo someone else said they'd done the same thing, with good result, nothing new under the sun!

I think it was Ed Dee, amongst others, who put a light spring on the free end of the rack to achieve the same effect, with the bonus that if the linkage failed the rack would be pulled to the stop postition

I did consider knocking up a whole new linkage with rose joints, but went down the 'if it's not broke' road and saved a few bob.

Happy new year.
Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.

2Ton46

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Re: Project Roid
« Reply #22 on: December 28, 2017, 02:14:14 PM »
If you happen to have a fancy phone, I've found it very useful to use the slow-motion video feature. Have not seen that mentioned on the board yet. Can see lots of things that you wouldn't otherwise. Maybe useful for your balance attempt, as you'll be able to see it hop in relation to where the flywheels are, and if you keep the same camera angle should be able to see how your weights are changing the hop. It is also useful for troubleshooting other issues, especially things that don't seem to move right in operation, but are not obvious when shut down.

2Ton46

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Re: Project Roid
« Reply #23 on: December 30, 2017, 02:31:08 AM »
Spent some time on the project again today.  Decided that I'd better listen to 38ac and get my flywheel keys in proper.  It took removal of a little more material than I thought it would from the keys but in the end I've got them in much better. One of my flywheels does not quite run true, but with the key in proper it seems to be slightly better than it was. The key on that one was not in but maybe an inch, and was probably tilting the wheel on the shaft.  That wheel also has evidence that someone with a big hammer was hammering the edge of the hub, mostly above and around the keyway. Not sure why, but probably where hammering in the key and missed a bunch. The taper on mine seemed to be fairly well matched to the keyway, once they tightened up they were making contact nearly everywhere at once. Most of the material I removed from the flat bottom of the key, as the whole thing needed to sit lower to get all the way in. Only needed some light filing on the tapered section to knock down a few rough spots and a few dings from the hammer man. Both wheels looked fine upon inspection of the bores so in theory they weren't damaged by my test runs. Hopefully I've gotten the keys correctly shaped and they stay tight.  Accidentally got one in just slightly farther than my puller can get behind so that maybe interesting at some point, too. Still plenty of room for a wedge type puller though.

Also spent some time with the governor spring and linkages.  With the rpm adjusted down to 550, there were a couple of problems. The first was that with the spring tied to the factory hook, there weren't enough threads to get down to 550.  So i added a small washer hooked between the spring and the hook to get the threads back in a reasonable spot, but this created a problem for starting.  The spring would cease pulling open the rack a little before the rack reached full open.  Sometimes on startup, the governor would close the rack up until the spring started acting again, but it was not always enough fuel on a cold start to keep things accelerating while getting both decompression levers moved into the run position. Without that little bit of spring to open the rack back up as the engine started to stall it was annoying. Once both cylinders were firing it would be a little sluggish to get to speed set point, but would maintain fine with the constant fan load I have for it right now.  Probably would not be the best with a large variable load. The other issue I've had is the slop in the linkages, sometimes there would be considerable movement on one side with none on the other, as well as everything moving back and forth with vibrations, probably contributing to some minor hunting.



So I found a couple of springs that were the best I could do at the half sold out spring display at the hardware store.  After much looking around, I decided to place them as you see in the photo, one on each pump.  The springs aren't very strong and are barely stretched with the rack closed. They are hooked into the pin hole from both sides to even out the twist on the yoke and prevent binding. They provide enough tension to keep the linkages tight against the main governor spring. This tension also allowed the elimination of the washer and further adjustment so the governor spring is always in tension even with the rack open fully. I suppose they would close the racks upon some failure with the rest of the system as well. It seems to be better responding than it was, but probably still a little less responsive than it was with just the original spring with the rpm set for 650. I think it would be better if the springs added at the pumps were just a little lighter pull. But it is a little more consistent on startup now. This has also eliminated the slop in the linkage, as all pins are under tension at all times, and movement of the rack on one side is instantly mirrored by the other side.

2Ton46

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Re: Project Roid
« Reply #24 on: February 05, 2018, 05:03:52 AM »
It was a warm day today, and the dogs really liked the wind from the yard fan. They figured it was a nice place to nap in front of. Also did some test running of the air compressor with the 'roid.  Seems to work well.  Set the compressor up to clutch itself when it reaches pressure, and then restart when pumping up is needed. I might need a longer spring on the governor, seems that there is quite a bit of drop with the addition of the 5HP load of the compressor in addition to the fan load before it catches up to speed. A gentle bump of the rack by hand when the load is added gets it right back up to speed so it isn't over loaded, just slow to react. It does get back up to speed on its own, just takes it the better part of a minute to do so. The system can also be adjusted so that the pump runs continuously and cycles just by the unloader if one is doing something with a large compressed air demand to reduce the clutch cycles. In the video it is just dumping some air back to the atmosphere to provide a false load for the compressor to cycle on.  Continuous operation reduces the speed fluctuations some what, as the compressor remains turning throughout and is somewhat less of a power fluctuation to the unit when it cycles. The clutch saves a noticeable amount of power during the unload cycle though so it appears to be worth the effort. The video shows a couple of cycles while in clutch operation.

https://youtu.be/YqoTgewlDkI

dieselgman

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Re: Project Roid
« Reply #25 on: February 05, 2018, 09:37:35 AM »
Very clever... Rube Goldberg would be proud!

I love your gadgets and gizmos. This made me smile and laugh. Tons of fun there.

dieselgman
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BruceM

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Re: Project Roid
« Reply #26 on: February 05, 2018, 04:23:37 PM »
Loved the compressor video, and admire your designs!

I've been thinking about adding a clutch to my 6/1 air compressor;  I have been using just the pneumatic unloaders but it still loads the engine more than I'd like.  For your clutch-  how are you avoiding belt wear during unloading (slack belt)? 


38ac

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Re: Project Roid
« Reply #27 on: February 05, 2018, 07:30:08 PM »
Excellent! Like it.
 I see you added pump cam oiling also. That governor is purdy lazy acting  you should be able to get it a bit better than that.
Collector and horder of about anything diesel

2Ton46

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Re: Project Roid
« Reply #28 on: February 06, 2018, 03:39:15 AM »
Glad its fun to watch. Thats part of the reason I made it. Also, the video doesn't do it justice, its really the most pleasant air compressor I've ever been around partly to the nice pump, but a lot to do with the engine noise as well.

As far as belt wear, most of the belt is guided away from the moving pulley when its slack.  There are guide pegs around to help the belt maintain a favorable shape when it is loose. There is sometimes some contact on the top edge of the pulley, but the belts are kind of floating there being held up by their natural shape, so any contact is minimal. If I notice that it is a problem, I could probably help it stay off the top of the pulley with a hook on the idler arm placed so that it guides up the belts just a hair more when the arm is fully raised. There are also some adjustments in the guide pegs that could get the belts moved into a little better position with some tinkering with the adjustments. I don't have enough run time on it to tell if wear is going to be a problem. I have not noticed any heating or signs of damage to the belts as of yet.

Yes, the cam oiling seemed like an excellent idea, and was pretty straightforward to implement with your instructions. I suspect the governor does not like my linkage tightening springs, they are probably too stiff. I'm chasing down some alternatives that should get the job done with less force. A longer spring down on the adjustment arm would also help, the short one it came with rapidly decreases its force as the rack nears full open, and thus it isn't as able to overcome the slight spring pressure from the linkage slop springs anymore.  Its too bad that the hardware store here seems to have a large rack of all types of empty slots for springs and never seems to have any of the smaller ones in stock. I could size up something close by feel, but a list of specs to order one might be a shot in the dark. I'll see about venturing to a few other stores sometime this week.

I also found and corrected an intermittent binding on the far side arm under the pump. It was allowing the lever under the pump to get too far to the side and that would cause binding if everything was in the right spot, but not all the time so it was hard to find and I had missed it when I initially went through the linkages. I suspect it was able to bind more often when the engine was in operation than it did when it was shut down. A further de-burr of the pivot and the addition of a thin washer as a spacer cured it. Although this helped the laziness, it was not a cure.

BruceM

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Re: Project Roid
« Reply #29 on: February 08, 2018, 04:27:30 PM »
Thanks for your insights, 2Ton46.  I've been thinking about a pneumatic powered tension device for my 6/1 driven compressor much like your hydraulic arm, vs a jack shaft driven by a flat belt which can be shifted to an idler of same diameter.  Just a matter of comparing which is easier to implement now.