Author Topic: Bodging with Boris........  (Read 5586 times)

Offline Ian S C

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Re: Bodging with Boris........
« Reply #45 on: October 17, 2017, 10:18:34 AM »
Just wondering, how many ball races have you got on the main bearings, it looks like two on each side.  It's often suggested that the shields on the bearings are removed, the grease washed out and replaced with a low viscosity oil, although I'll admit that I leave the bearings intact.
Things look as though they are getting back together.
Ian S C

Offline Stilldrillin

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Re: Bodging with Boris........
« Reply #46 on: October 17, 2017, 06:55:10 PM »
Looks to be a good 'redesign' of this engine  :ThumbsUp:  :ThumbsUp: I await the first trials  :wine1:

Thanks Roger! I have a show, on Saturday. Hoping I can give it a good, first run.

Just wondering, how many ball races have you got on the main bearings, it looks like two on each side.  It's often suggested that the shields on the bearings are removed, the grease washed out and replaced with a low viscosity oil, although I'll admit that I leave the bearings intact.
Things look as though they are getting back together.
Ian S C

I'm not after a high speed/ powerful engine, Ian. Just a, "show speed", runner. A total of eight bearings. All shielded.
They are now turning more freely, than they were.....


The crank assembly, is finished....




It cycles nicely. No tight spots.......





The flywheel, is next. At 7" dia. It's a little on the large side, for a mini lathe......




The original bore was unsuitable. So, I drilled out, oversize, and plugged with a piece of m/s. Held in with the ever faithful sleevelock.

The rear boss, held in the chuck jaws, has been machined nicely true to the rim. Allowing me to set the rim running, within a thou'.

Now, I'm starting to open up to a 10mm dia bore. Hopefully. Perfectly true to the rim......

Does anyone have any tips, for producing, such a bore?
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Online Roger B

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Re: Bodging with Boris........
« Reply #47 on: October 17, 2017, 09:45:57 PM »
A small boring bar if you have one. If not a 2 flute endmill (6 or 8mm) in a suitable holder used as a boring bar. Drills or reamers will follow the existing bore.
Best regards

Roger

Offline Stilldrillin

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Re: Bodging with Boris........
« Reply #48 on: October 17, 2017, 11:11:18 PM »
A small boring bar if you have one. If not a 2 flute endmill (6 or 8mm) in a suitable holder used as a boring bar. Drills or reamers will follow the existing bore.

Thanks for that Roger!  :ThumbsUp:  Sometimes, this old brain needs a little help!  :facepalm:

I have a toolpost chuck......




Also, some 6mm dia, shanked, carbide boring bars!

I can bore a drill diameter, recess. To give a concentric start, to the incremental drills.
Then a 10mm recess, to start the reamer.....  ;)

Thanks again, for the nudge.....  :praise2:
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Online b.lindsey

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Re: Bodging with Boris........
« Reply #49 on: October 18, 2017, 12:35:12 AM »
Wow, some impressive progress this week David. Hope the trial run at the upcoming show goes well for you.

Bill

Offline Stilldrillin

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Re: Bodging with Boris........
« Reply #50 on: October 19, 2017, 07:36:21 PM »
Roger, Bill.
Thanks, Chaps!

The first drill through, had been 5.5mm. I thought it was pretty concentric.  :thinking:

I then bored a recess. To steady, the subsequent, 7.5mm drill.......




I could feel/ hear the drill, cutting. As it held true, against the eccentric pilot hole.  :ThumbsUp:

The next drills 8.5, 9, 9.5, were started off the same way. They cut very sweetly.

Same again, with the 10mm reamer. Making a perfectly sized hole. Running perfectly true!  :whoohoo:

It just goes to show... A little care, and forethought, is all that's needed. Very pleased!  ;D


After installing the flywheel, I realized, I had time for a quick test run.......

<a href="http://www.youtube.com/watch?v=dlk_io15Ez8" target="_blank">http://www.youtube.com/watch?v=dlk_io15Ez8</a>


Only, the cosmetics left to do, now......  :hellno:

Thanks for looking in!
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Offline crueby

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Re: Bodging with Boris........
« Reply #51 on: October 19, 2017, 10:21:01 PM »
Running very well! Congratulations!

Online b.lindsey

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Re: Bodging with Boris........
« Reply #52 on: October 19, 2017, 11:30:36 PM »
A very unique mechanism David. And it runs very well obviously....well done!!!!

Bill

Offline 10KPete

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Re: Bodging with Boris........
« Reply #53 on: October 19, 2017, 11:37:28 PM »
That is really an interesting valve "eccentric". I wouldn't have thought it would run so well! And it runs beautifully!!
Congratulations David!!

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline Ian S C

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Re: Bodging with Boris........
« Reply #54 on: October 20, 2017, 03:38:44 AM »
I quite like the displacer drive, I have used a scotch yoke on one of my engines, these straight line systems do help reduce the length of a motor quite a bit, but may not be as efficient as a conventional conrod and bearing, but it's good to try all types of action as it is pleasing to see the different motions of each. 
Ian S C
« Last Edit: October 20, 2017, 09:35:29 AM by Ian S C »

Offline Ian S C

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Re: Bodging with Boris........
« Reply #55 on: October 20, 2017, 09:33:46 AM »
I now see why there are two bearings each side, there are virtually two crankshafts as the displacer crank pin  is it's self held in bearings and free to rotate, or more exactly stay still while the crankshaft it's self rotates.  Being a bit slow on the uptake it took a little time to work it out.
Ian S C

Offline Stilldrillin

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Re: Bodging with Boris........
« Reply #56 on: October 23, 2017, 07:26:58 PM »
Chris, Bill, Pete.
Thank you, Gentlemen!  :ThumbsUp:

, but may not be as efficient as a conventional conrod and bearing, but it's good to try all types of action as it is pleasing to see the different motions of each. 
Ian S C

Can you tell me, why not, Ian?  :thinking:

There is a dwell, at either end of travel. Allowing more time for heating/ cooling.
 Also between those two points, the travel time is more rapid than a simple, crank oscillation......

The engine ran happily, for over 5 hours on Saturday. Stopping, only for meths top ups......  :whoohoo:




It has much more torque, at the crankshaft, than any of my other engines....

Thanks for looking in!  :)
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Offline scc

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Re: Bodging with Boris........
« Reply #57 on: October 23, 2017, 07:57:27 PM »
I have never really bothered much about hot air engines :thinking:   This well made example is wonderful :ThumbsUp: I may be converted!
Regards         Terry

Offline Stilldrillin

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Re: Bodging with Boris........
« Reply #58 on: October 23, 2017, 10:36:38 PM »
I have never really bothered much about hot air engines :thinking:   This well made example is wonderful :ThumbsUp: I may be converted!
Regards         Terry

Thanks Terry!  :ThumbsUp:

Give one a try! (Pick a decent sized one). Nothing more frustrating. When they sulk.....   :rant:
 But, so satisfying, when it all comes together, as a good, reliable runner.  :cartwheel:
David.
Still modifying bits of metal... Occasionally, making an improvement!
Still drilling holes... Sometimes, in the right place!

Offline Ian S C

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Re: Bodging with Boris........
« Reply #59 on: October 24, 2017, 02:08:24 AM »
David, I was just a little worried that there might be a bit of extra friction with the pin moving up and down in the crank pin, but as you are getting a good power output, it could be a good way to go.
Ian S C