Author Topic: Liney RV-1 - A New Double Wide  (Read 20967 times)

Offline sshire

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Liney RV-1 - A New Double Wide
« on: October 25, 2013, 03:03:13 AM »


Liney RV-1 - A New Double Wide

Part 1

“The way to succeed is to double your error rate.”
Thomas J. Watson
Chairman and CEO of IBM


I had the plans for the RV-1 on the bench for a few months while I was working on the boiler. I was following Bill Lindsey’s build and didn’t realize, until he finished it, that it was smaller than I had imagined. So, all dimensions times two seemed doable.

I printed a second set of the drawings and, with a calculator to check my math, wrote the new 2X dimensions on the plans.
I went through the brass and aluminum stores and ordered what I didn’t have.
Most pieces laid out on the bench all ready for their weight reduction.


The base plate, a .375 6061 piece, becoming square. First try with a high helix end mill. Much better surface finish on aluminum.



The 2” face mill gives a beautiful surface.



Even with the DRO, I feel better marking out the piece. That way, I have a better chance of catching a screwup before it happens.



After finding the 0,0 corner and zeroing out the DRO, I plunged an end mill and began making the cutout for the flywheel. I changed to a smaller diameter end mill for the corners and finishing pass.



With the flywheel opening cut and mounting holes drilled, it was good to see that each hole was perfectly positioned on the scribe lines.



I like to mill a bevel on plates. Cutting the edge against the fixed vise jaw makes everything work nicely with the bevels all around matching at the corners. Cut, turn 90 degrees, cut, turn, etc.



First part done. Of course, more sanding and polishing will come later.



The flywheel bearing “towers” are next. I had seen these acetal bearings with stainless steel balls and though that this might be a good engine for a tryout. They are described as “no lube” if run under 2500 rpm. Maybe.


The primary problem is that they are wider than the .5” x .5” brass square. Even though there appears to be plenty of room for a wider piece, I had another idea. And I’m not in love with straight square pieces.


That looks like it might fit.



A bit of drilling and boring got me just under what I need. The engineering data for the acetal bearings gives from 0 to -.003” interference. The bearing O.D. is .625.





I’m going to line bore the last 1 or 2 thou when the blocks are mounted on the baseplate. For now, the bearing almost presses in.



Good enough for now so I parted off two pieces.



I wasn’t overly concerned with the internal finish as that will go away when they are bored to size.



For the bottom of the bearing tower, I rounded off the corners of the .5” square bar.



The two pieces are roughly to length. The action then moves to the mill to make both the same length and to mill a recess for the round bearing shells.



Ready for their debut on the soldering stage.



That’s today’s output. More tomorrow. Don’t change that channel.







Best,
Stan

Offline Don1966

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Re: Liney RV-1 - A New Double Wide
« Reply #1 on: October 25, 2013, 03:35:26 AM »
Gee! Stan your just a go getter buddy, you spit out parts like tomorrow. Looking good though and I'll be following you until completion which will be a couple of days. Keep it coming man!  :ThumbsUp:

Don

Offline smfr

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Re: Liney RV-1 - A New Double Wide
« Reply #2 on: October 25, 2013, 04:11:12 AM »
Lots of good tips even in the first post! I like the tip about how to get an even bevel on all sides.

Simon

Offline sshire

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Re: Liney RV-1 - A New Double Wide
« Reply #3 on: October 25, 2013, 06:35:40 AM »
Simon
I credit John Moore (Bogs) for showing me the bevel technique.

I did get an email from Doug at Liney. He recently put the RV1 in Alibre and is going to model it in 2x to see if there are any issues. Gotta love support like that.
Best,
Stan

Online sco

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Re: Liney RV-1 - A New Double Wide
« Reply #4 on: October 25, 2013, 06:40:03 AM »
Yeah I thought the bevel trick was neat too.

Thanks,

Simon.
Ars longa, vita brevis.

Offline mklotz

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Re: Liney RV-1 - A New Double Wide
« Reply #5 on: October 25, 2013, 05:12:08 PM »
Variants of Stan's bevel trick are useful in other oft-encountered machining operations.

Say you have a square plate and want to put a hole in each corner for hold-down bolts or some such.
Put one plate edge against the vise fixed jaw and but the adjoining edge against a work stop.  Drill the first hole, rotate the plate ninety degrees, drill again and so on.  Each hole will be located identically in relation to its plate corner.  With a bit of workpiece flipping, you can use this trick on rectangular plates as well.

It's a handy method of duplicating features on a workpiece.  Give it a bit of thought and I'm sure you'll find some personal applications.
Regards, Marv
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Offline b.lindsey

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Re: Liney RV-1 - A New Double Wide
« Reply #6 on: October 25, 2013, 09:21:27 PM »
Very nice start Stan...already lookin g forward to tomorrow's update :)

Bill

Offline sshire

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Re: Liney RV-1 - A New Double Wide
« Reply #7 on: October 25, 2013, 11:52:50 PM »
Thanks, guys. Here's your fix for today.


Liney RV-1 - A New Double Wide

Part 2


After silver soldering the bearing towers, I cut a piece of 2”x2” brass to rough size and then off to the mill to square it. This will be the valve block.



Switching rods in the depth mike to a 1” to 2”, I milled the block until it was close enough to a 2” cube.





Now a 1” diameter through hole for the rotary valve (tomorrow’s part du jour). Center was located and spot drilled.



Then a series of drills starting with about .25” and getting up to my largest, a .75 Silver and Deming.





I took the .75” hole out to 1” with the boring head. I really need a thicker shank boring bar that is long enough. This was the only bar I had that would go 2” deep. While the knee power feed moved up slowly, I kept fiddling with the VFD speed dial to keep the chatter to a “less than butt clenching” level.
Surprisingly, the bore had a good finish. I’m thinking that indexable boring bars might be a good idea.



The block is attached to the baseplate with 4 screws. The drawings show them as 2-56. At this scale, 5-40 look about right. Drilled and tapped.



After discussions here and with Doug at Liney, I did go with a 2x diameter hole for the intake and exhaust. Both the exhaust at the top and the intake in the back, have counterbores for the exhaust stack and intake piping. . Since I’m in the process of standardizing everything to ¼-40, thats what I drilled and tapped.





With the drilling and tapping complete, the last op on this part (aside from sanding and polishing) is milling the “cooling” fins.

.125 end mill. .25 movement for each cut. I marked out the lines for the stopped cuts.



So there is your part for today and I’m at this step. Rotary valve tomorrow.



Best,
Stan

Offline Don1966

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Re: Liney RV-1 - A New Double Wide
« Reply #8 on: October 26, 2013, 12:59:29 AM »
Nice chunk of brass Stan and some great progress. Shes starting to look like an engine already. Looking forward to tomorrow's fix.  :ThumbsUp:

Don

Offline b.lindsey

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Re: Liney RV-1 - A New Double Wide
« Reply #9 on: October 26, 2013, 02:09:20 AM »
Nice surprise as I wasn't expecting more until tomorrow. That valve body looks terrific Stan, as do your modified bearing stands.

Bill

Offline sshire

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Re: Liney RV-1 - A New Double Wide
« Reply #10 on: October 26, 2013, 04:16:18 AM »
Trying to do a part a day. Something usually gets in the way but that's the plan.
Best,
Stan

Offline sshire

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Re: Liney RV-1 - A New Double Wide
« Reply #11 on: October 26, 2013, 11:28:04 PM »
Liney RV-1 - A New Double Wide

Part 3

The Rotary Valve


The O.D. of the valve is 1”. The closest 6061 round I have is 1.5” and, since the largest 5C collet is 1.125”, the 5C chuck had to come off and the 3 jaw replaced it. I actually have a custom 1.25” collet but that wasn’t a help here.



The 6061 round was chucked in the 3 jaw and turned down until it fit. Then the 5C chuck was put back on. With the small live center in place, the piece was turned to 1.00”



As I got close, I kept checking with the valve block until it just slid on



Next, 1” of each end is turned to .5” diameter. I first marked the length with a parting tool.



Again, when the DRO indicated that I was close, I began measuring. This is close enough.



Then the part was marked for the 1" length of the .5" O.D. section at the other end.



The valve is 4” in length and is to have a .25” hole from end to end. This directs air (or steam) to the cylinders. With no 4” long, .25” drill, I had to drill from both ends and have the hole meet in the center.
That’s what I love about the collets and the Set-Tru chuck. Take parts out, put them back, flip them end for end and it still is correct.



This is not the center drill from the previous photo. It’s the .25” bit in as far as it would go. I must have pulled it out 20 times to clear chips.



The part was reversed in the collet and drilled from the other end.



The holes met perfectly. This ¼” tube slipped right through.



Moving to the mill.

The final op was the cross drilled holes to meet the air passage. I found center and then the edge.



And then drilled until it met the passage.





The finished rotary valve.



The progress photo.



Hoping to get an early start on the cylinders tomorrow. The football game starts at 1:00. (That’s the one where the ball has pointy ends)






Best,
Stan

Offline b.lindsey

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Re: Liney RV-1 - A New Double Wide
« Reply #12 on: October 27, 2013, 12:42:31 AM »
Looking great  Stan!!  What material will you use for the flywheel?

Bill

Offline sshire

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Re: Liney RV-1 - A New Double Wide
« Reply #13 on: October 27, 2013, 02:01:32 AM »
It's coming along, Bill.
The flywheel will be cast iron from the nice fine grain hunk I got at Cabin Fever.
Best,
Stan

Offline Don1966

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Re: Liney RV-1 - A New Double Wide
« Reply #14 on: October 27, 2013, 03:54:19 AM »
Stan I can help but compliment you on the photos it's like reading a good book with all the details jumping out at you. Nice progress and beautiful work.  :cheers:

Don

 

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