Smithers Build of Brian Rupnow's IC Engine

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Hi Pat, thanks for the compliment.

No cad/cam for this part, just a written txt file uploaded to the cnc, after all
it is really only a rectangular part with corner radii and some holes.

I have attached the program I used to make the part, note though there are a lot of "T17" tools. This was because I only had 3 spare pockets in the magazine due to running another job yesterday. Just do one operation then change the tool, do the offset and restart the program for the next operation.

Definitely not a production program, but for 1 part it worked well.

Bearing bores will be milled 1mm undersize then finish bored after the base, side plates, bearing caps & cylinder head are dowelled & bolted.

Andrew

View attachment O5700 RUPNOW BASE.pdf
 
Neat ... ;)
I used to do my own g-code programming ...but finally started to use a CAM program.

It's not clear to me about the bearing hole just yet ... maybe a photo when you do it would help. I think I will do a practice hole and see what happens.

Interesting G-code ... the Feeds and Speeds are about the same that I was going to try ... that is if speed is RPM.:D

Well it's about 7:15 pm Friday here and your Saturday afternoon is just starting (should be 12:15 pm). So have a great weekend.


Pat H
 
Andrew--This is just a drop in to say Hi and offer up a word of encouragement. I am currently "breaking new ground" with my CDI ignition that I have purchased. ( I don't believe that my engine requires a CDI to run it, but I have always wanted to try one.) Cheers mate, keep up the good work. I will probably repeat this message to all the others who are building the Rupnow engine.---Brian
 
Andrew---Whats happening? I hope you are well. You got off to such a great start on the Rupnow Engine, but we haven't heard from you in a while.---Brian
 
Hi all,
Sorry, few weeks off to deal with work commitments, family etc. Back now, I'll make another start on the project after the weekend.
Time to spend an hour or so going through the posts to see how Brian and everyone else building this engine is going.

Andrew
 
Smithers--We are looking foreword to seeing more of your marvelous work. My engine is finished, Swifty fron Australia has his engine 99.9% finished, Gus from Singapore and Cogsy from Australia are neck and neck (actually Gus may be a bit ahead). Canman from England has fallen far behind because of lack of equipment and impending marriage, Rivergypsy from England ? seems to have abandoned the project until he finishes the "Entablature" steam engine, and Luc from Quebec, Canada has been so busy making money that he hasn't had time to work on his engine lately. Pat Hutcheson from California keeps making encouraging noises but hasn't started a post about his build. Wagnmkr from Lindsay, Ontario has said that he may start to build one when he returns from his holiday in England. We don't have any builders from Asia nor South America as yet.---Brian
 
Hi Brian,

Still a bit slow in resuming this build, have been doing a bit of cad on the parts but no swarf!! Will be ordering the ignition parts today along with sparkplug and boot (same as yours and Swifty's).
Think I'll just put the feet up today and catch up on all the posts.
Andrew
 
Smithers--I've got my fingers crossed for you.--I've never had a machinist friend in Tasmania before. Looking forward to seeing some more of your build.---Brian
 
Hi guy,
I must apologise for the lack of posts in the last few weeks, in the absence of swarf I have been modelling Brian's engine to ensure what I am thinking will be correct. In a previous post I mentioned I was going to dowel the side plates and cylinder head to the base for alignment, I am still going to do this and have attached a pdf of the model to show what I am doing. I cannot believe I cannot publish exploded pdf's in Alibre so hopefully the 3 pages will give the idea of what I am going to do.
Basically 1/8" dowels locating the side plates and cylinder head to the base and hollow dowels (6mm diameter) locating the bearing caps to the side plates.

I also had a delivery from the post man today, the CDI for this engine. I was going to get it from where Brian and Swifty bought theirs but found this site in Western Australia http://www.dlenginesaustralia.com/dlshop/ignition-systems.html

Excellent service, $98.30 AUD, ordered Wednesday morning, received package today (Friday), couple of pics attached. The only other thing I had to by was the battery holder and 4 2500mAh nickel metal hybride batteries at a cost of $21 AUD.

The only real changes I have made so far from Brian's original design is the hollow dowels for the bearing caps, increased centre distance for the bearing cap mounting bolts and the slight profile change to the caps.

View attachment rupnow engine assembly.pdf

IMG_1051.jpg


IMG_1052.jpg


IMG_1053.jpg
 
Hi Andrew, the PDF is looking great. I haven't bothered with dowels at this stage, the bearings will align the caps, so the dowels there may be a bit of overkill. I found that once I assembled the bearings, side plates and crank, everything was lined up anyway.

Paul.
 
Hi Paul, Yes you are right, it is a bit of overkill but I just wanted them there for the final boring of the bearing bores after the individual parts are roughed out. My idea is 1mm undersize on bores, assemble base, side plates, head & bearing caps then bore the bearing bores.

Haven't been on here for a while, I'll catch up on some reading on everyone else's build.

Andrew
 
Just thought that I might mention that the alignment of each side of the crank is of course critical. I just made sure that each of my flywheels were the same diameter, and when I bolted them together I had them sitting on a surface plate and against an angle plate as well, so they were aligned in 2 planes. This method worked out well.

Paul.
 
Smithers--I am very happy to see you posting again on this engine. We currently have 3 running around the world, Canada, Australia, and Singapore. It will be great to follow one coming to life in Tasmania.---Brian
 
Hi Brian,

Glad to be back!!

By the way, Tasmania is a state of Australia.

Andrew
 
I see that in your address.--However, to me Tasmania is a strange and exotic place on the opposite side of the world, and deserves mention in it's own right. All I really know of Tasmania is that it was at one time a penal colony for Great Britain, and it is the only place I know of that has its own personal devil named after it.--That's probably about on par with "Everybody in Canada is a lumberjack or fur trapper, and they all live in igloos".---Ya gotta love that good old 1950's public school education!!!---Brian
 
Well, after a long absence I am back, into work tomorrow for the side plates and cylinder head, have a better camera now so pics should be better.
BTW Brian, how many engines worldwide now,
Regards, Adrew
 
Smithers--Very happy to see you back. There are still only 3 running Rupnow engines around the world that I am aware of, but a new one has been started and is being worked on by Pat Hutcheson in California. Someone calling himself Krankie Frankie has apparently started to build one but has never started a post about it. I don't know if Gus in Singapore ever got the governors working on his or not.---Brian
 
I'm still here, trying to post whenever I can ... should be this weekend.

Glad to see that you are making progress ... looking forward to some
pictures with you new camera. What one did you get?

Pat H
 

Latest posts

Back
Top