# My Rupnow Hit & Miss Engine.aka my very first hit & miss engine.



## gus (Aug 19, 2013)

Hi Gurus,

Looks like I have all the material left over from the Webster Engine project to make engine.Piston Rings too.
Went out to buy #1606 ball bearing.Ended up with a backup selection----
NTN R6ZZ which is slightly smaller with O.D.Boring con-rod to take ball bearing
will another challenge.:hDe:
Gurus,
Please advise bearing fit for big end. Push fit,light drive fit,medium drive fit??

By this Friday,should make enough progress to post.


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## Cogsy (Aug 19, 2013)

Have fun with the build Gus. I'll be watching your progress.


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## gus (Aug 19, 2013)

Cogsy said:


> Have fun with the build Gus. I'll be watching your progress.



OK!  Guru Cogsy.


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## Swifty (Aug 19, 2013)

Glad you decided to make a start Gus, I allowed a size for size fit for the bearing on the big end. By that I mean that I bored out the big end the exact size of my bearing, 26.00mm bearing, 26.00mm hole. If anything, you can leave the hole 0.0127mm (0.0005") undersized.
Size for size still makes for a tight fit, you wont push it in with your hand, I just warmed the big end up using the flame on our gas stove, If you make it too big you can always loctite it in.

Paul.


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## gus (Aug 19, 2013)

Swifty said:


> Glad you decided to make a start Gus, I allowed a size for size fit for the bearing on the big end. By that I mean that I bored out the big end the exact size of my bearing, 26.00mm bearing, 26.00mm hole. If anything, you can leave the hole 0.00127mm (0.0005) undersized.
> Size for size still makes for a tight fit, you wont push it in with your hand, I just warmed the big end up using the flame on our gas stove, If you make it too big you can always loctite it in.
> 
> Paul.



Hi Paul,
Looks like shrink fit.Will go for shrink fit.
Thanks . Paul.


 Slide fit with Loctite is very dicey. The thumping and knocking will loosen up bearings.

Cold pressing will damage con-rod.


Next question. The bearing fit on the side plate to clamp bearing.


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## Swifty (Aug 19, 2013)

Bye the way Gus, I did have to remake a couple of smaller items due to stupid mistakes, but it was no more than 15 min work. Another hint, when making small parts, make sure that your swarf tray is clean, saves a lot of time looking for parts that fall in the tray, I found out the hard way.

Gus, I used the same fit on the side bearings that I used for the big end.

Paul.


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## canadianhorsepower (Aug 19, 2013)

Nice to see you building one to Gus

should be back at mine tomorow


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## Swifty (Aug 19, 2013)

Gus, I just noticed that you are posting in "Finished Projects", you may want to move over to "A Work In Progress".

Paul.


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## Davewild (Aug 19, 2013)

Good luck Gus, I wish you every success, and will be tagging along, unfortunately you will get no advice from me I'm just starting out.

Regards

Dave


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## Gurus (Aug 19, 2013)

i'll be watching and waiting.

___________________________________

 I had only loneliness to walk and embrace with .....


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## gus (Aug 19, 2013)

Swifty said:


> Bye the way Gus, I did have to remake a couple of smaller items due to stupid mistakes, but it was no more than 15 min work. Another hint, when making small parts, make sure that your swarf tray is clean, saves a lot of time looking for parts that fall in the tray, I found out the hard way.
> 
> Gus, I used the same fit on the side bearings that I used for the big end.
> 
> Paul.



Hi Paul,
Thanks for  the useful tips.
From the day my mum let me walk around the row of machineshops,
I have seen many odd practices by vet. turners to pick up small pieces before they disappear forever in the swarf pan. 
1. using a small rod to pick small bush during parting before its drops off.
2. using a soup ladle to catch the part.
3. clean up the swarf pan before doing small parts.
4. put in a newspaper over swarf make part location easier.
5. do nothing .

Still not very smart in posting into the correct slot. My Humble apologies.


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## gus (Aug 19, 2013)

Time 8:30 am. Just wonder why I woke up at 6:30am.
I have all material on hand to build the "Rupnow" Engine.
See foto. By Friday should see some progress. As advised by my Gurus,take time to prep.
Plan procedures.
Today will see blanks for baseplate and two side plates cut. 
Boring sideplates to take bearings will be a tough killer. Again will prep and anticipate.
Sure hate to donate to "Rag&Bone" man or the scrap bin.:hDe:


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## Gurus (Aug 20, 2013)

Difference between school and life?
          In school you are taught a lesson and then given a test.
          In life, you are given a test that teaches you a lesson

__________________________________________________________________


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## gus (Aug 20, 2013)

Been working smart. 

Blanks for base and side plates cut . The Makita Bandsaw was worth every cent paid for. Took less than 10 mins to cut blanks.
All three pieces milled to size as per print.
Mini Mill lived up to its name and had to be stretched to mill the lengthy jobs.
As I said some fixtures have to be made. 
Got lucky.Milled to as per print dimension.Not too bad for three hours of bandsawing and milling.
Tomorrow will a brain storming day. Make fixtures to bore bearing holes to fit.Will give due time to this "boring" job.
The Poor Man's Boring Head will be called upon to do a Man's Job.


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## Lawijt (Aug 20, 2013)

Great Gus that you started with that engine. I will follow it onto the point of my chair.
Do you other engine run already with your new ignition system??

Also I will build that engine , but there is a problem with my Lathe. It turns slightly conical. I don't know what the problem is. So I leave it for what it is & I read on the forum to learn.

Barry


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## Brian Rupnow (Aug 20, 2013)

Hi Gus--I sent you the email before I seen that you were posting in "Finished Engines" instead of "A work in Progress". Welcome to the build, and if I can help in any way, please let me know. I hope all goes well with your build.----I wouldn't get too excited about the fit of the bearings. I used a boring head to bore all of my bearing holes and when I seen that I was getting close, I advanced the boring head in .001" increments until the bearing would go into the prepared hole with just finger pressure. If the bearings are a bit loose in the sideframes, then file a bit off the underside of the bearing caps to pinch them up a bit tighter.---If the bearing fit is a bit loose in the big end of the con rod, then use a center punch and punch a series of "light dimples" around the inside of the con rod bore---that will tighten up the fit.--And remember---Loctite is your friend!!!-Brian


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## Gurus (Aug 21, 2013)

Hi Gus 
I like the engine. But I do not have a lathe. 
I'll be watching your progress.
Ask let successfully.   
___________________________________
John.


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