Author Topic: Br2 Rotary  (Read 2028 times)

Offline John Roberts

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Br2 Rotary
« on: January 02, 2019, 01:09:07 PM »
Hi anyone making the Br2 Rotary to the Blackmore design? I seem unable to find past threads on this subject.
Currently making the crankshaft.

Offline Ramon

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Re: Br2 Rotary
« Reply #1 on: January 02, 2019, 01:45:29 PM »
Hello John, I don't think there are any threads on here but there is at least one on Home Model Engine Machinist - HMEM

I began a Bentley many years ago and though I have a considerable amount of the machining done there is still a long way to go. Currently it sits in a dormant stage.

I have made mine to  the drawings both in the original ME magazine article and the book including the addendum list published by Professor Chaddock in the ME magazine. I have never seen the set of published drawings so can't comment.

There were quite a few errors to be careful of that may or may not be on the drawings proper.
Though I can't remember exactly where, I found there was a discrepancy in the build up of dimensions on the crankshaft on both book and article drawings. I ended up drawing mine out on graph paper (long before I had 2d CAD I should add) and the error I think was in the order of some 3mm. Though my engine parts are still currently unassembled I have put the case and crank together to check those findings against those drawings and all was proved correct. I may still have that drawing on graph paper somewhere.

Good luck with yours - hopefully, unlike my own failing you will go all the way  :ThumbsUp:

Regards - Tug
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline John Roberts

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Re: Br2 Rotary
« Reply #2 on: January 02, 2019, 02:45:23 PM »
Tug,
Thanks for your reply. Yes there are many dimensional  errors in the book. I modelled the complete engine in CAD so am confident that it should all sit together.
The HMEM forum is mainly about the Ageless design which appears very different but still interesting to follow.

So far I have made the Crankcase, Cambox, thrust box and Conrod assembly.

What made you stop yours? I have now bought all the materials for this project so financially I owe it to myself to finish this project!

Offline mikemill

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Re: Br2 Rotary
« Reply #3 on: January 02, 2019, 05:32:38 PM »
John
I made my version some 30 years ago It still gives me pleasure to look at it, I took around two years to build as there is a lot of work in it, but that is part of the pleasure.
I used Blackmores book as a guide, canít remember if there are any wrong measurements in the drawings.
Good luck with the build if you get stuck I will try to help.
Mike

Offline Ramon

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Re: Br2 Rotary
« Reply #4 on: January 02, 2019, 06:36:08 PM »
Hello again John,

Well you should have no issues if you've been able to do it all in CAD  :ThumbsUp: I must have stopped on mine long before I picked up basic 2D. I don't know why I stopped, I recall thinking that I wouldn't do the cylinder heads until I had a good degree of workshop continuity but that was quite some time ago - and they were done long before this forum began I'm fairly certain.

One of the reasons it's stalled currently was/is the making of the piston rings. They are all parted off ready for finishing but until they are done I can't finish the pistons - the internals are all done on them so once they are finished I can assemble all the parts made. I have varied interests I'm afraid all of which conflict with each other at times - well most of the time I guess  ::)

I made a die for casting the top inlet manifolds - did that at work around 1997/8 - and about five years ago I loaned it to someone 'from up north' that I met at a local ME show. We stayed in touch and he returned it this year with twelve lovely castings made from it. Despite that big boost toward the build I still have little desire at this point in time to continue with it - I don't have that motivation to tackle long term projects as I once had I guess.

As with Mike - should you need any help please say - I'll do my best to help

Regards - Tug
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Jasonb

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Re: Br2 Rotary
« Reply #5 on: January 02, 2019, 06:58:23 PM »
The build of one is currently being serialized in Model Engineer by Mick Knight, it's a bit of a hybrid mixing Ageless Engine and Blackmore features.

Offline John Roberts

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Re: Br2 Rotary
« Reply #6 on: January 02, 2019, 07:29:09 PM »
Many thanks to you both. Mike that photo of your engine is amazing. I am trying to make as much as I can using my CNC mill. The thought of making this engine using only manual machinery would have put me off starting this project.
It is good to know that I now have now found two fellow builders for advice should I have any quires in the future.
As for the intake which I have not modelled it yet. I thought I might be able to get them lost wax cast in China.
They could make a rapid proto type or 3d print master from my model.
I have no intention of casting my own!
I have been following the Model Engineer series for interest. Jasonb

Offline mikemill

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Re: Br2 Rotary
« Reply #7 on: January 03, 2019, 09:54:40 AM »
John

Further to my comments I to have a steel die for the inlet elbow, casting from ali and machining them is one of the easier tasks, don't be put off casting as the small amount of ali can easily be melted and poured, you are welcome to borrow the die but donít forget to heat it first.
Regarding tool making I recommend making two set of tools especially the exhaust hollow cutter as they will break even when you think you are feeding very gingerly.
As you have CNC you might take a different approach and not have to make all the tools.

Mike

Offline John Roberts

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Re: Br2 Rotary
« Reply #8 on: January 03, 2019, 01:34:00 PM »
MIke,

Thank you for your kind offer. I would love to borrow your die. I may choose to have a go or use it to make  waxes. I have contacts in the silver trade so might get them cast lost wax.
 
My email address is ********.

Regarding the exhaust hollow cutter that will not be necessary as CNC machining makes that operation easy.

Did you have problems making the valve springs? getting the correct temper seems to be more by luck.
I have got some main springs to try. If this fails I may try and track down some tapered coil springs but what size wire thickness and dimensions would have to be by trial and error.
What about the oil pump did you cast that as well? I was thinking of fabricating out of brass and getting it plated.
Attached is a photo so far.
« Last Edit: January 03, 2019, 05:23:45 PM by Kim »

Offline Kim

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Re: Br2 Rotary
« Reply #9 on: January 03, 2019, 05:28:43 PM »
John,
I removed your email address from your post.  It's best to send this kind of personal information in a Private Message directly to Mike.  It's not that we think anyone on the forum would use your email address inappropriately, but these messages are out in the public for all to see (member or otherwise).  And there are many bots that scour the web looking for email addresses to use in inappropriate ways.  We just want everyone to be safe.

Sorry for the intrusion on your thread here.
Kim

Offline John Roberts

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Re: Br2 Rotary
« Reply #10 on: March 11, 2019, 04:12:35 PM »
Cylinder heads done next job is making the coil springs and the valve cages.

Offline John Roberts

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Re: Br2 Rotary
« Reply #11 on: March 11, 2019, 04:13:53 PM »
Another photo.

Online Jo

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Re: Br2 Rotary
« Reply #12 on: March 11, 2019, 04:26:07 PM »
Looking good

Did I mention we have a set of BR2 Castings that joined the collection last week  :embarassed: So I will be following along.

I have checked the commercially available drawings for the BR2 and they have been updated with the corrections.

Jo

P.S. Don't forget there are castings needed for the oil pump and cover.
Usus est optimum magister

Offline John Roberts

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Re: Br2 Rotary
« Reply #13 on: March 11, 2019, 08:01:06 PM »
I bought some intake castings from The Steam Workshop. Do you know of oil pump and cover castings that are commercially available. May be they sell them as will. I didn't ask!

Online Jo

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Re: Br2 Rotary
« Reply #14 on: March 12, 2019, 12:07:41 AM »
 :ThumbsUp:

I don't know if they are available. I know Eric has the dies for them but he hasn't got around to doing anything with any of his foundry stuff for years   :disappointed:

These are the oil pump castings.

Jo
Usus est optimum magister