Cogsy Builds Rupnow Engine

[Brian Rupnow]

Cogsy--About the bevel gears---A complete set of involute cutters is horribly expensive. I believe I paid about $500 for eight 24DP cutters and the proper arbor to run them on. They are primarily intended to cut spur gears with, although as Swifty has shown in the "Articles" section of this website, they can be used to cut bevel gears, although it looks like a pretty tricky set-up to me. You must also have access to a rotary table and dividing plates.--I'm not sure what tooling you have available, but you will need some kind of gear cutting set-up to cut the timing gears. I took what I considered the easy way out by buying the bevel gears that I used. My price here in Canada worked out to "around" $25 each, purchased from McMaster-Carr in USA.

 

[johnny1320]

Cogsy--About the bevel gears---A complete set of involute cutters is horribly expensive. I believe I paid about $500 for eight 24DP cutters and the proper arbor to run them on. They are primarily intended to cut spur gears with, although as Swifty has shown in the "Articles" section of this website, they can be used to cut bevel gears, although it looks like a pretty tricky set-up to me. You must also have access to a rotary table and dividing plates.--I'm not sure what tooling you have available, but you will need some kind of gear cutting set-up to cut the timing gears. I took what I considered the easy way out by buying the bevel gears that I used. My price here in Canada worked out to "around" $25 each, purchased from McMaster-Carr in USA.

Hi Brian, I tried to buy some parts from McMaster-Carr and they told me they won't sell to Canada, how did you get around that?

John

 

[Brian Rupnow]

Basically, you find someone who has been in business since before this "Don't sell to Canada" edict was put in place. I have a large number of business acquaintances who do business with McMaster Carr every day. Its not that they won't sell to Canada--Its more like they will not accept new customers in Canada.---Brian

 

[canadianhorsepower]

Basically, you find someone who has been in business since before this "Don't sell to Canada" edict was put in place. I have a large number of business acquaintances who do business with McMaster Carr every day. Its not that they won't sell to Canada--Its more like they will not accept new customers in Canada.---Brian

McMaster Carr are retailer's if you search a little bit you'll find out the manufacturer's distributer in Canada and find out that GBS sell's their product at a lower price Give it a try

 

[gus]

Hi Luc,

Will buy gears from GBS as a backup just in case my DIY conical gears won't mesh.

Been reading Ivan Law's book on "Gears and Gear Cutting. He has a good spread on cutting DIY Conical Gears. Swifty succeeded in cutting his own.So I am following.

The Hit & Miss Engine should be completed by end September/early October and will running w/o hitting & missing till the DIY gears are done.

 

[Brian Rupnow]

Gus--I have a copy of "Gears and Gear Cutting" by Ivan Laws, and he gives a very thorough explanation of how to machine bevel gears using an ordinary involute spur gear cutter, using the same method as Swifty outlines in his excellent "How To" article. The next time I get an overwhelming urge to "machine something" I may try it, just to see if I can. I'm rather burned out on machining at the moment, but maybe later in the fall I'll try machining s set.--Brian

 

[gus]

Gus--I have a copy of "Gears and Gear Cutting" by Ivan Laws, and he gives a very thorough explanation of how to machine bevel gears using an ordinary involute spur gear cutter, using the same method as Swifty outlines in his excellent "How To" article. The next time I get an overwhelming urge to "machine something" I may try it, just to see if I can. I'm rather burned out on machining at the moment, but maybe later in the fall I'll try machining s set.--Brian

Hi Brian,

At the age of 70 ,Gus is more proned to burned out. Pehaps I should have taken a good break before jumping in to build the Hit& Miss engine but it was so hard to walk away. After getting the major portions up and having the raw engine assembled and hand turned,my burnt-out seems cured. Now taking it easy with the minor parts.

Weekend fishing seems to eased off the Burnt-Out. This week-end fishing wasn't that good but was relaxing to see friends bringing up rod-benders and buying them dinner at the marina having their catch for dinner.

All set to cut the minor parts. Now totally refreshed.

 

[Cogsy]

Just a quick update to let everyone know I'm still persevering. Side plates and bearing caps are progressing, in fact nearly done. As with almost every part of this build, I seem to be making small errors for some reason. This time I again misread a dimension and shaved the bearing caps where the bolts go through a little thin. They'll still work but I just keep buggering up somehow. I won't mention that I had a small crash with a slitting saw arbor - I'm trying to forget it.

Today was my wedding anniversary so I only had limited time to get onto the shed (that's why I didn't take any photos today) and I managed to make the push rod guide. Working carefully from the drawing, paying special attention to dimensions and...my bolt holes were not equally spaced from each end of the part . I scratched my head for a while, measured each bolt centre distance (all correct) and recalculated how far from the end the first hole was supposed to be (1/4" - it was correct) and it all checked out. So how come the other end was so far from the end??? Well, I started the job by making a blank to the dimensions given in the plan description at 3/4" x 5/16" x 2.860" and then went from there. However, on the body of the plan itself, the overall length of the piece is actually 2.680" . Once I shortened it up, my bolt spacing is spot on. It made me very happy to not be the cause of the error for a change, although I haven't heard about anyone else making the same mistake, so maybe I have to rethink how I read plans in future. I'm sure Brian will amend the drawing but it's really not a big deal.

That's all I got done but the weekend is only a couple of days away.

 

[Brian Rupnow]

Cogsy--Just chalk that one up to Dyslexia. You are the first person to notice that.----Brian

 

[petertha]

McMaster Carr are retailer's if you search a little bit you'll find out the manufacturer's distributer in Canada and find out that GBS sell's their product at a lower price Give it a try

Please provide a web link. I tried googling 'GBS', not getting hits.

 

[Brian Rupnow]

Cogsy--You must be just about ready to post an assembled picture of your marvelous creation. We are all looking forward to it.---Brian

 

[Cogsy]

Cogsy--You must be just about ready to post an assembled picture of your marvelous creation. We are all looking forward to it.---Brian

Hmmm, I think your eagle eyes may have spied that most of my parts lack mating holes so far .

I must make a confession, up until this point I haven't actually been making an engine - I've just been making parts. However, with this gentle prod from Brian I've changed gears and started to make the parts fit together.

I'm fighting illness so I only got a couple of hours again today, but I drilled and tapped many holes and I nearly have it to a point where it can be mock assembled. As a side note, my transfer punches are feeling very neglected as of late. This build has forced me to learn to trust my dials and work from measurements instead of punch marks. Touch wood, it's working for me so far.

I also got the pushrod done today, but again, no photos. I'll take some soon, just have to work out how to unfocus the camera a bit .

Thanks for looking.

 

[canadianhorsepower]

Please provide a web link. I tried googling 'GBS', not getting hits.

here it is

http://www.gbs.ca/

 

[gus]

Hmmm, I think your eagle eyes may have spied that most of my parts lack mating holes so far .

I must make a confession, up until this point I haven't actually been making an engine - I've just been making parts. However, with this gentle prod from Brian I've changed gears and started to make the parts fit together.

I'm fighting illness so I only got a couple of hours again today, but I drilled and tapped many holes and I nearly have it to a point where it can be mock assembled. As a side note, my transfer punches are feeling very neglected as of late. This build has forced me to learn to trust my dials and work from measurements instead of punch marks. Touch wood, it's working for me so far.

I also got the pushrod done today, but again, no photos. I'll take some soon, just have to work out how to unfocus the camera a bit .

Thanks for looking.

Hi Cogsy,

Take care. Get well soon.

 

[AussieJimG]

It's not a race Cogsy, just do what you can when you can.

Jim

 

[Brian Rupnow]

Jim is right. Its not fun to be sick, we all know that. Do what you can, when you're able, and I hope you feel better soon.--Brian

 

[Brian Rupnow]

Cogsy---Are ya getting better??? I've been back and forth half a dozen times to physiotherapy trying to get the kinks out of my wretched old spine, but I'm doing better. Hope you are still making some progress on the engine. I see Luc finally got enough other peoples work done that he's turning out Rupnow engine parts again. Gus went away and got eaten by a big fish or something, but I'm sure he's going to post a runner soon. I didn't have much "real" engineering work all summer (which was just fine by me), but now I'm busier than a two headed cat!!! I've got three different customers all squalling to have their jobs done first, so I'm not doing much in my little machine shop right now. If yer not better, get better.---Brian

 

[Philjoe5]

Get better soon Cogsy. Your statement:

I must make a confession, up until this point I haven't actually been making an engine - I've just been making parts.

is too true. First you make some parts, then you get to the point where they have to mate together. I'm there right now too. It can be frustrating but hang in

Cheers,
Phil

 

[Cogsy]

Thanks for the words of encouragement guys. I have made a recovery, but I got a little sidetracked on another small project - http://www.homemodelenginemachinist.com/f36/yet-another-diversion-21834/ . Back on track now, and a promising weekend ahead. If I can sweet talk the lovely wife (she sometimes reads my posts...) I should get a decent amount of shed time. My focus will be on getting the parts mated up nicely, lapping the valves in and cutting the cam. With luck I'll have a nearly assembled engine to display by Sunday, except for the dreaded carby.

 

[AussieJimG]

... except for the dreaded carby.

That's what I thought when I built my Bonzer so I wimped out and used one of Jan Ridders' Vapour carbys. That got the engine running with minimum fuss.

Later on I tackled the complicated carby and found that it wasn't so hard after all.

So if you run out of time, try the vapour carb.

Jim