Model Engine Maker
Engines => From Plans => Topic started by: b.lindsey on July 27, 2013, 10:31:37 PM
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Thisi will begin what should be a relatively short build of the Liney Machine RV-1 two cylinder oscillating engine. While this is offered as a kit http://www.lineymachine.com/lineyrv1kit-p-2695.html?osCsid=df1711b4a444c2df252d0dd2684d6802 I opted to just purchase the plans and use materials I had on hand. This would make a good second build for a beginning modeler, but is not beyond the realm of a first engine project if suitable care is taken. I will be following the plans as supplied by Liney, though material choiced may differ in a few parts like the flywheel which will be made from cast iron rather than the suggested aluminum, mainly to add more weight here. The build will be done on the Sherline lathe and mill.
Even with more experience, this should prove to be a fun little project. By doing a log on the build it is my hope that it may entice others to document buildls on other engines suitable for newcomers to the hobby. To that end I will probably post more pictures than I normally would.
Before beginning, I wanted to use this project to try out a set of A.R. Warner HSS insert tools I picked up at Cabin Fever and have been itching totry on the Sherline (see the picture below) So with that ...here we go
Bill
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The first part will be the flywheel. As already noted, I am using some gray20 cast iron I had on hand rather than aluminum as called for in the plans. Also the plans call for a four spoke flywheel rather than the through hole version shown on their web site. Either design would work though I am sure.This post will document preparing the blank for the flywheel. Picture 1 shows facing the cast iron to get down to the .450" width specified. Photos 2,3, and 4 show center drilling, drilling, and reaming the .124" center hole. The chuck capacity of the Sherline required chucking on the OD of the cast iron which was not truly round at this point.Once the center hole was finished, the relief on the first side was made with a small boring bar to a depth of .150" x 1.200" diameter as shown in picture 5.Note that in picture 6, the jaws were put back to their usual configuration so as to chuck on the ID of the relief on the first side. This also helped keep the center bore concentric with the splindle axis. Once the relief was bored in the opposite side, a turning cut was made to bring the flywheel OD down to the 1.500" specification.
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With the blank finished, iit was time to do the spokes. The rotary table was centered on the mill (photo 1) and the blank (still in the lathe chuck) was attached to the RT. Each quadrant cut out required three holles...one near the center and two on the periphery. In this case i moved the rotary table to the correct offset for the first hole and drilled all four of them by rotating the RT 90 degrees for each hole...then relocated to the second position and did the same thing and so on. Photo 2 shows the four innermost holes. Photo 3 shows the blank after all 12 holes had been drilled. Then its just a matter of connecting the dots so to speak as the next two pictures show. With the linear cuts made, the RT was used to connect the holes on the periphery. If you don't have a RT, the through hole design could be used as shown on the Liney site, and using trig to locate the position of each hole. The last two photos show the finished flywheel though it may need a little filing and cleanup in areas.
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Nice work Bill, I will be following you on you journey.
Don
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Thanks Don...shouldn.t be too long a journey i hope. More to follow tonight...had to stop for dinner :)
Bill
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This post almost doesn't count but the plans call for 1/8" drill rod for the axel through the flywheel (their term not mine) and the two crank pins. So while at the lathe, i cut these oversize and then faced to length and very slightly chamfered the ends.
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Guess I was in more of a lathe mood today so I found a scrap length of brass and made the exhaust stack. Photo 1 shows turning the 1/4" and 1/8" diameters. In photo 2 the 1/16" bore is drilled through the 1/8" section and a ways into the 1/4" top section. In photo 3 a needle file was used to better round the transition between the two sections. Finally the part was cut off, faced to final length and the top portion drilled until it joined the 1/16" bore previously shown. The last photo shows the finished part.
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Last post for today...a piece of aluminum was turned to the diameter needed for the spacers that fit between the valve body (the cubic brass piece shown in the Liney photo) and teh cylinders. I turned the OD long enough to make both spacers, then drilled and reamed to .251" (not shown) then parted off both pices to about .105" width and finished them on some 220 grit paper to get down to the .100" thicknedd called for.
Hopefully there will be more progress tomorrow.
Thankd for looking.
Bill
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Your moving right along there Bill. How are the insert tools working out for you?
Don
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So far so good Don. I had purchased a boring bar from them a few years back and have loved using it too. They make some quality tools for my money (usual disclaimers)
Bill
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Yea I agree about quality Bill, I have there grooving and threading tool. I may just buy there set.
Don
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Thanks for the flywheel machining demo, I should have used a slice of CI for mine. Do you use the 3/8" End Mill Holder or a collet for cutters?
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Jan, for anything other than miniature end mills with a 3/16" shank, i use the 3/8" end mill holder and find it works well.
Bill
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Got a couple of parts done today...the bearing stands and the rotary valve. First the bearing stands, which are 1/4" square brass x .625 long so not large parts at all. I centered the stock in the 4 jaw chuck and drilled the end for a 2-56 tapped hole, then parted it off and did the same for the second one. This is shown in photo 1. Then moving to the mill, located the point for the .125" cross hole for the crankshaft. The plans call for reaming the cross hole to .126" but the drill rod for the crankshaft measured a few tenths under .125 so I reamed these at .125" and got a good running fit as a result (photo 2). After tapping the bottom holes where the stands will mount to the base plate, I cleaned up the four edges of each stand on some 320 grit paper and ended up with the finished parts shown in photo 3. One other note on these. The plans call for counterboring the cross holes to .142" x .200" deep but that would only leave .050" of thickness supporting the crankshaft which seemed pretty slim to me and I see no reason for the counterbore (yet) so I opted not to counterbore these holes. I for some reason they turn out to be necessary, I can add them later.
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Next up was the rotary valve from aluminum. Starting with a piece of 3/4" dia. aluminum rod, I faced one end and turned the .250" extension that will fit into the cylinder, trued up the major OD for a half inch or so, and then drilled the 1/8" through hole (photo 1). This resulted in what is shown in photo 2. Then reversing the part in the chuck the same was done on the other side. At that point the larger diameter needed to be turned down to .500" as shown in photo 3. Then it was over to the mill vise again to locate and drill a hole on each arm of the valve through to the center bore (photo 4). This is a single acting engine and these holes will ultimately allow air to enter and exit the cylinders. Later on at assembly the intake and exhaust ports will be drilled through the valve housing and through the center part of the valve itself to insure proper alignment based on crank position. This is explained in more detail in the notes whoch are a part of the plans. The last photo shows the finished valve.
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Looking good Bill, your not messing around here buddy. You seem to be making good time here.
Oh! And I just ordered me a set of Warner insert tool set.
Don
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Cool Don!! What size did you order and what will you be using them on? So far I am very poleased with these!!
Bill
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Bill, bought one of their grooving tools at CF and it has worked great. Boys got their HSS tooling down real good. I really appreciate you doing this build. I think there are a lot of us here that really hope that one day we can be as good as a whole lotta folks here. While we look and dream there is a group that wants to build something that runs and build our skills along the way. I love the advanced builds and study each one closely, learning set-ups and technique. But, most can't start at that level. We need to be able to say (say it with me Dave ) " It's a Runnah " After a couple of those you can start stepping the game up every build. I've gotten one Liney to run ( Thimble ) and I'm praying my second will. Did you look at their radials Bill :stir:. Keep up the good work.
Eric
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Thanks for the comments Eric. Based on what I've seen on your RV-2, I have not doubts that it will run and it also has a lot of character i think. The RV-1 isn't nearly as complex as yours so you've already made a quantum leap over the thimble engine. Ya gotta love those little thimble engines though or rocking engines as some call them. I have looked at Liney's Halo engine...who knows...maybe one of these days :)
Bill
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Cool Don!! What size did you order and what will you be using them on? So far I am very poleased with these!!
Bill
Bill I ordered the 3/8" shank with HSS and Carbide inserts and plan to use them on casting and steel. I have a cheap Chinese set I have been using which works OK, but the insert tips keep chipping on them. I tried to hone a small radius on the tip, but to no help still chips so I will try these.
Don
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Hi Bill
Just came across your build log and read it from the begining.
Love the photos (keep them coming) and the explanations. I am sure that a detailed build log would be of assistance to anybody (of any skill level) building or contemplating building the same model.
Keep it up. You are really flying along.
Vince
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Vince, thanks for having a look I have certainly enjoyed your Corliss build and that one's on my list, just letting you guys work the kinks out ;D
Bill
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Hi Bill
Looks like fun project and it is always nice to see work being done on the Sherline tools; I will be following along with your build and looking forward to the next installment.
It all looks great so far and the cast iron flywheel is a nice touch :ThumbsUp:
Dave
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Nice work Bill, you are making some quick work of it all. :cheers:
BC1
Jim
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Very nice, Bill. Everything looks great. I hadn't seen this engine before, so will be following along.
BTW I love my Warner tools. Nice people too. They know their metallurgy.
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Thanks Dave, Jim, and Stan. Need to scrounge a few more materials today and hope to work some on the base and cylinders tonight. For now though another work week begins ::)
Bill
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Well you're moving at the speed of Chuck Fellows anyway, so we will let you go to work today. Don't you hate it when work interferes with a perfectly good project :Jester:
Eric
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Sure do Eric and still several years away from retirement. This was the first weekend I've had some concentrated time in the garage in a long while and if was nice....but...you still gotta pay the bills right :)
Bill
Edit: I am so far behind Chuck (and others) in productivity, they needn't even look in their rear view mirror...but as we all know its not a race. In this particular thread I will be elated if even one newcomer or maybe I should say new poster jumps in as a result of the build.
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Bill,
Just downloaded these plans. The spec material for the pistons is stainless. Do you think this is necessary? I've been doing OK so far with 6061 in brass cylinders. Even some brass in brass.
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Stan, I would think that S.S. is overkill too. I am likely going to use either 1018 or 12L14 for the pistons. In addition I don't have an 11/64 reamer and don't plan on buying one for just this engine, so will likely enlarge the bore to 3/16 and enlarge the end that engages the crank pin accordingly. Take a look at both the piston drawing and the bearing stand drawing...both show that .144 counterbore almost all the way through. I don't understand the need for this ay all and plan to ream the piston to .125" all the way through without any counterbore just as i did for the bearing stands. If you can figure out why they did this counterbore, please clue me in...just seems to weaken the wear characteristic of these parts in my view. Also as I noted earlier, for the drill rod i had on hand, a .125" bore was a perfect running fit rather than the .126" shown.
Bill
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Bill
I was wondering about all of the counterbores also. I'm going to email Doug at Liney to see if there is some reason that we're missing.
Since the next project is the PM Horizontal Boiler, and I intend to run the rv-1 on steam as well as air, steel pistons are not going to work for me.
I'll report when I hear from Doug.
If anyone else has built this engine, let's hear your thoughts on counterbores.
Stan
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Doug was quick to respond. Here's his email answer.
"The counter bore in the bearings and pistons is not required. Less thickness on the axle and pins is less drag and a gap to put some oil for lubrication. You could make the bearing post larger and use ball bearings if you want to get a little fancier but the steel axle through brass will work fine.
You can see this in the completed engine photo. I will try to get some better photos for builders:
http://www.minicastings.com/acatalog/Liney-RV-1_complete.html"
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Thanks Stan....pretty much what I had thought... as well as making it a little more forgiving in terms of alignment too. I don't see that a ball bearing is needed so will just stay with the straight through .125" on mine.
Bill
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Agree, but it's good to hear it from the source.
Best,
Stan
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I built the RV-1 a number of years ago. Was fun to make in my "early" machining years (ok, still early relatively speaking !).
Runs like a bat outta Hades too - very fast and doesn't need a lot of air pressure :)
Looking good so far !! If I had one thing I'd change, it'd be to use a heavier flywheel (brass). The AL one is almost too light. Though it really doesn't matter much since it's not going to be doing any real work.
Mike
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Thanks Mike and to your point I used cast iron for the flywheel as noted earlier in the log for just the reasons you mentioned.
Bill
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Another weekend so back to the build. Obviously didn't get much done this week other than gathering a few scraps of material for the weekend.
I started out this morning on the base. The material I had on hand was some 3/16" aluminum plate rather than 1/8" but shouldn't matter and has the benefit of the flywheel protruding less beneath the underside of the base. In the first photo, I am just squaring up the piece and bringing it down to the final size. In photo 2 I have drilled the 6 holes for mounting the bearing stands and the valve body. In addition, I drilled four 3/16" holes...one at each corner of the cutout for the flywheel. Finally in photo 3 a 3/16 dia. end mill was used to finish cutting out the opening for the flywheel.
The last 3 photos show the base with the bearing stands and flywheel mounted and everything seems to turn freely even withough the counterbores in the bearing stands.
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Looks like a lot to me Bill and looking good at that.
Don
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Then it was on to the valve body. I has tried to order a few inches of 1" square brass stock at the beginning of the week but the $7.00 worth of brass was going to cost $15.00 to ship so I decided not to do that. Instead, I had a length of 1.25" dia brass that I cut down on all four sides, yeilding the piece shown in Photo 1. The 1" width is the main critical dimension, and I can live with the other slightly rounded edges from an asthetic standpoint.
Photo 2 shows drilling the four mounting holes on the underside of the valve body and they are right on the line where the flat bottom meets the rounded edge but still shouldn't be that noticable once mounted to the base plate.
In photo 3, the mill was used to spot and drill a 3/8" hole through the center of the valve body. This was then centered in the 4 jaw chuck on the lathe and indicated true as shown in photo 4. The ports for the air connection and exhaist had been drilled over at the mill previously. Photo 5 shows the boring bar enlarging the 3/8" hole to a smooth .500" bore for a nice slip fit of the valve in the body.
Finally in photo 6, it was back to the mill to add the decorative fins to the top of the valve body using a 1/16" dia end mill.
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The last few photos for now show the valve body added to the base along with the previously installed bearing stands and flywheel. The valve and spacers are also shown in the valve body since these parts had been finished previously' I'm beginning to see a little engine in there somewhere now!
Next up will be the cylinders and pistons and crank disks, but that will have to wait till tomorrow.
Thanks for checking in!
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Very nice, Bill! I like the details on the valve body.
Simon
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Thanks Simon...it works for me. Used up some scrap and saved the $22.00 in material and shipping for something else :) Honestly i don't think it looks bad at all.
Bill
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It looks great Bill, especially those curved edges.
Vince
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Bill
Looking great. The rounded edges give it a much smoother look than the drawings.
Just curious if you have the Sherline boring head for the mill? That would have allowed you to do all ops there.
Watching this with great interest since the RV-1 is in the lineup right after the boiler.
Best
Stan
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Bill
That was a good use of material and an all around improvement in appearance. A nice added detail.
Jerry
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Ditto!....I like that look better.
Dave
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Thanks guys for the positive opinions on the rounded edges.
Stan, i do have the sherline boring head but the only boring bar i currently have for it was toovshort to go through the 1" thick body, hence the 4 jaw and AR Warner boring bar in the lathe. But it could otherwise be done on the mill as you say.
Bill
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Today was devoted to getting the two cylinders made. Once again, I didn't have the 1/2" square brass stock on hand bud did have some 1/2" x 3/4" stock which I milled down to 1/2" square (photo 1). After squareing it up it was milled to length yielding the two blanks shown in photo 2.
Next the blind cross hole was drilled (see photo 3). This will fit onto the two "arms" on either side of the valve. Not show but done at the same time was 2-56 tapped hole from the end of the cylinder into the cross hole for fixing the cylinders to the valve arms. Then the cylinders were turned on end, squared up in the mill vise and drilled and reamed for the pistons (photo 4). The cylinders at this point are shown in photo 5.
The it was back to the lathe and 4 jaw chuck where I used the dial indicator that same as done on the valve body to make sure the cylinder bore was along the lathe axis. Then a portion of each cylinder was turned to a .480" diameter as shown in photo 6. Lastly the round portion of the sylinders was chucked in the 3 jaw chuck to chamfer both edges of the remaining square part of the cylinder (photo 7).
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Last pictures for today show the assembly up to this point with the cylinders now in place and just waitng for the pistons and crank disks which will be next.
Thanks for having a look.
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Looking good there old Pal. Ain't no grass growing under Yo feet. The day of reckoning ain't fer away.
Whiskey
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Depends on how the week goes Eric...but hope to have it running by next weekend at the latest. How's that gear coming along?
Bill
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I know, making a living. I want to get to the point I can make a life 8)
E
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Bill love the look buddy, it's a nice looking little engine. :ThumbsUp:
Don
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Bill
Coming along really well. Looks like a fun one. Looking forward to building it.
Best
Stan
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Looking good Bill. I've been consuming your thread the last couple of days. It's a good read.
Cheers
Steve
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Thanks Don, Stan and Steve. Its getting close enough now that I want to get it finished to see how it runs. Stan...it really is a nice little project for taking a break from more demanding ones like your pumping engine, and with reasonable care I don't see why it couldn't even be a "first" project for newcomers to the hobby. The plans are clear and there are adequate notes to help out with the machining and assembly as you have no doubt seen already.
Bill
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Looking at other builds of this engine, I see that the cranks have no offset from eachother, rather than the usual 90°. Is that just to make the valve arrangement simpler?
Simon
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Simon, the answer to that is yes. With this arrangement there is only one hole drilled through from the inlet and exhaist ports into the bored out center of the valve which then feeds or exhausts both cylinders. To offset the cranks by 90 degrees there would need to be two independently acting valves or at least a means of isolating the feed and exhaust from each culinder independently. I had even thought about modifying the plans to accomplish that but then realized that since the cylinders are only single acting, offsetting the cranks by 90 degrees would not guarantee a self starting engine, which would be the main reason for doing that. I agree it would make for a more interesting motion but at the same time, I am trying to stick with the original plans as much as possible since this thread is aimed more towards less experienced builders who may wish to give this engine a try.
I may well play around with this once this build is finished and I have a few thoughts as to how to accomplish it still rolling around in my head. Good question though!
Bill
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Very nice work.
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Only got a little work done last night, but did get the pistons started. Since the square stock was 3/16" and the cylinders had been reamed to .1865 I was worried that I wouldn't be able to turn the round piston part from the square without either leaving slight flats on the fours sides or ending up with an undersized piston. After centering the 3/16" square in the 4 jaw as closely as I could, I turned the pistons down to just over .1865 and polished gently with some scotchbrite. Fortunately it cleaned up and left no flats and the fit in the cylinder was near perfect, meaning the pistons would fall into the cylinder of their own weight, but would gradually slip into it with the open end of the cylinder closed off. I'll try to get the square ends milled to length tonight and drilled/reamed for the crank pins.
Bill
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Managed another short session in the shop last night and managed to get the two crankdisks finished with the exception of drilling and tapping for the set screws to fix them to the crankshaft.
In photo 1 a 1" diameter piece of brass is turned to the .820" dia. required and drilled/reamed through the center for the crankshaft. The length of stock turned was enough (barely) to later cut off both crankdisks.
Photo 2 shows the same piece still in the lathe chuch, but transferred over to the mill where it was centered with a DTI and the offset hole for the crank pin drilled and reamed.
Photo 3 shows using a 1/4" dia endmill to reduce the stock on either side of the crankpin, leaving the counterweight portion opposite the crank pin side. In this case a series of plunge cuts were made moving the table .025" for each step until the cutout was roughed in and leaving the last .025" for a finishing cut at full depth. The same procedure was done on the other side resulting in what is shown in this photo. Sherline has a nice little adapter for mounting the lathe chuck directly to the mill table, but a cautionary note here: make sure the chuck is torqued very tightly else the miling cutter forces can loosen the chuck and ruin all the work up to this point. Been there, done that and learned that lesson the hard way!
In phooto 4 the two crankdisks had already been parted off from the original stock, and then each was put back in the 3 jaw chuck to face off one or both sides as needed to get to the finished thickness of .200"
Lastly, the two nearly finished crankdisks are shown. A bit of edge clean-up with a file and adding the set screw hole through the counterweight side and they will be ready to have the crank pins installed and added to the crankshaft.
That leaves only finishing up the two pistons, making a fitting for the air inlet and we'll be ready to give it a try.
Thanks for looking.
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You're in the short row now my brother. It's looking super and quite a testament for the Sherline equipment. Looks like we is starting up two Liney products this month.
E
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Very nice bit of work there Bill. You should just about be ready to get her running.
Oh! By the way got my AW Warner set in and I really love the way they cut.
Don
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Thanks guys. If I don't get it running this evening then it should for sure tomorrow evening..assuming of course that there aren't any alignment problems, etc. Stay tuned :)
Don...when I started cutting the brass bar last night for the crankdisks, the original edge on the tool was dragging so I finally had to rotate it to cutting tip #2. Everything else was done with the original edge and I think I can yet hone that one back to life as well. Even if not, I can live with that. Its been used on cast iron, aluminum, brass and steel and with interrupted as well as continuous cuts. I am really sold on them! Only one spare insert came with the set though, so I should order a few more to have on hand.
Bill
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Bill
Almost there. Waiting for the run.
Sharpening Warner inserts is simple.
Lay a piece of wet/dry on a surface plate or other flat.
Remove insert and place it face down on the wet/dry.
Press with finger and move the insert around and around.
Done.
The relief angles and tip rounding as done by Warner are maintained.
Other than the cutoff/ groover inserts which I touch up on the belt sander, that's it.
Stan
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Nice work Bill!
Dave
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Thanks Stan. Will try that. Engine is finished and runs. Still need some fine tuning but that and video will have to wait till tomorrow night. Cute little thing i must say :)
Dave, thanks for looking in also.
Bill
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Good stuff Bill. I'll be tuning in for the video
Steve
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You really moved along on this one Bill.
Thanks for showing; I'm also looking forward to the video.
Kind regards, Arnold
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Here are the last few pictures of the build...drilling and reaming the pistons for the crank pin, milling them down to the final length, and then locating and drilling/tapping the crankdisks for the set screw that holds them in position on the crankshaft. Nothing much to show really but this finishes up the machining of all of the various parts.
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Then it was on to assembly and getting things lined up. With both cylinders working in tandem, it doesn't take much mis-alighment of the crankdisks to introduce some binding but after a little fiddling, things seemed to be pretty free. I did run if for a while last night on about 8-9 psi, but I hope this will come down as things run in a bit.
Below are just some photos of the finished engine, one in the palm of my hand for scale and the other two mounted (or rather just sitting) on a rapid prototyped base for now. Likely I will make a wooden base for it to match the rest of the collection but the RP base was done for a purpose as well. We have been discussing using the RV-1 at the project for a sophomore design project to be added to the curriculum next year. Ideally that project will include manual mill and lathe work (including some 4 jaw work on the lathe), some CNC mill work (possibly the valve body and the plate on which the bearing stands and valve body are attached), and finally a rapid prototyping element to the project...hence the base shown to see how it would come out. It seems like a doable project and I have already contacted the folks at Liney to see how we may license the plans for 40-50 students per year. Plenty of time to work out the details since its over a year off, but never too early to start!!
This evening I need to make a couple of spacer washers to keep the flywheel/crankshaft assembly centered better between the bearing stands. The design leaves plenty of room there and I would like to eliminate some of that slack. I will also try to make and post a video of it running as well after work this evening.
Its been a fun project and I appreciate those of you who have followed along and offered your support.
Bill
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That is really nicely done. Great job. After seeing actual size in your hand, I'm almost tempted to double scale it.
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That is a really lovely looking little engine :ThumbsUp: :ThumbsUp: :ThumbsUp:
And I too didn't realise just how small it is, it's really cute
Tim
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Already finished. That was quick. Great looking photos. I did not realise it's so small.
Vince
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Very nicely done Bill, I like it and will put it on my list of engines to build. :ThumbsUp:
Don
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Many thanks guys. If i can do this right heres a short video of it running...
(http://i257.photobucket.com/albums/hh207/wlindiii/th_RV-1_zps90ac0cbe.jpg) (http://i257.photobucket.com/albums/hh207/wlindiii/RV-1_zps90ac0cbe.mp4)
Lets just say the camera takes better pictures than videos.
Bill
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Nice runner! Sounds great also.
Great build, Bill.
Best
Stan
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Stan, if you wanted to, I don't see any problem with making one at 2X the original size, there is nothing magic about the dimensions that I see. Your new pumping engine would tower over it at this size ;D
Bill
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Ok. 2X it will be, although I could put the 1x on the catwalk ;D
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Stan, ya got a Bridgeport. lets go for 4x
Eric
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That turned out real nice Bill!
Congrats on a great little runner :cheers:
Dave
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Thanks Dave.... I may do a little painting like on the flywheel spokes and maybe the grooves in the valve body top. If so, I will post some final pictures and a better video.
Bill