First engine, even if it is only a wobbler.

Help Support HMEM:

Bushranger

Active Member
Joined
Jun 4, 2020
Messages
33
Reaction score
39
Location
The Rock, NSW, Australia
Prefer metric to those other strange numbers, lol. I'm doing a conversion to the closest metric equivalent, hopefully they'll work. I tend to use scraps for a lot of my work, especially in wood. I can dress it to any size I want, so that's not a problem.

A question though, if you don't mind. The inlet and exhaust ports on that engine seem to be a strange shape. Would it still work if they were round? Would certainly make the job quite a bit easier.
 

GreenTwin

Well-Known Member
Joined
Jul 2, 2021
Messages
343
Reaction score
206
Location
MidSouth
GreenTwin, may I ask why the inlet and exhaust ports on that engine are the shape they are? Would they also work if they were just round?
Round ports will work fine.
If you look at the old commercial oscillating engines, which were generally some sort of low level hoist engine, or some other non-critical task engine, the ports were not round.
The intent was to get a quick full opening of the port using the odd-shaped port, which is basically how a D-valve operates.

A round port will not give a quick and full port opening, but for a model engine, this is not important at all.
And I have seen at least one old commercial-looking engine that had round ports.

.
 

GreenTwin

Well-Known Member
Joined
Jul 2, 2021
Messages
343
Reaction score
206
Location
MidSouth
I enjoy filing, but it's hard on my hands, especially needle files, so I avoid it when I can. But it might be worth a go.
For very small ports, it is tricky to get an accurate shaped and located port, and I generally use round ports, which is what I used on my green twin oscillator.

For a larger engines, it would be easier to grind an odd port shape, say using a Dremel moto tool.

.
 

bsulli81

New Member
Joined
Nov 23, 2021
Messages
3
Reaction score
1
Location
cadiz
awsome work bushranger! good to see others acomplishments i am also building my first engine "the e-z engine build" from this site an your progress is motivating.
 

Bushranger

Active Member
Joined
Jun 4, 2020
Messages
33
Reaction score
39
Location
The Rock, NSW, Australia

GreenTwin

Well-Known Member
Joined
Jul 2, 2021
Messages
343
Reaction score
206
Location
MidSouth
GreenTwin, I take it you've seen the magnetically sprung wobbler https://www.homemodelenginemachinist.com/threads/magnetically-sprung-wobbler.28961/ I'm thinking of trying that idea out on your engine, but I think I'll build another simple wobbler with one to see if it works. If so, then I'll be starting on your design.

Guess I'll have to start another thread for that one, lol.
I have not seen that design.
Magnets these days have really become incredibly strong, so who knows what you could do with them.

I will probably redesign my dad's design at some point, and make castings for it, with bearings and bearing caps, etc.

I started to make castings for it many years ago, but I really was clueless about foundry work and engines at the time, and so I did not get very far with it.
I did make a pattern, and cast a few frames in aluminum, but that was as far as I got.

rImg_2392.jpg



rIMG_2405.JPG



rImg_2411.jpg



rImg_2414.jpg
 

GreenTwin

Well-Known Member
Joined
Jul 2, 2021
Messages
343
Reaction score
206
Location
MidSouth
If I were going to make one of my dad's engines today, I would probably build it more like a mini No.02 Cretors.

This is a full sized Cretors No.02.

rCretors-Horiz-02.jpg



rCretors-Horiz-04.jpg



rCretors-Horiz-05.jpg



rIMG_6582.jpg



rIMG_6584.jpg



rIMG_6589.jpg
 

GreenTwin

Well-Known Member
Joined
Jul 2, 2021
Messages
343
Reaction score
206
Location
MidSouth
The solid flywheels lend themselves well to bar stock construction.

I have gotten to the point where since I can make my own castings, I see every engine part through the lens of a casting.
Kind of like if you have a hammer, everything starts to look like a nail.

Edit:
I don't really like the looks of the rod end on a Cretors; it looks too much like a sewing machine part.
And those cap head screws are definitely not original Cretors items, but that is what came with that engine when I purchased it.
I will replace those screws with ones that match the original Cretors screws.
.
 

GreenTwin

Well-Known Member
Joined
Jul 2, 2021
Messages
343
Reaction score
206
Location
MidSouth
I think the No.02 Cretors with the smaller base looked better.

I think those slotted screws are original Cretors, but I must say I am not crazy about the looks of those either, although they are the original look of that engine.
Slotted screws look too much like sewing machine parts in my opinion, but to each their own.
I prefer the old style bolt look, which had a taller head than a new bolt.

raIMG_7082.jpg
 

Bushranger

Active Member
Joined
Jun 4, 2020
Messages
33
Reaction score
39
Location
The Rock, NSW, Australia
Nice engines, but to be honest, I prefer the look of your father's engine. Also, it would be an easier job to fabricate the base as I don't have any casting equipment, yet.

Where would be a good place to start a new thread for this? I'm seriously thinking of doing a better job on logging the work I do. Some of which is doing some pretty heavy reclamation of old CI scraps.

(Edited to change a word to something more appropriate)
 
Last edited:

Richard Hed

Well-Known Member
Joined
Nov 23, 2018
Messages
1,293
Reaction score
304
Location
Seattle
I think the No.02 Cretors with the smaller base looked better.

I think those slotted screws are original Cretors, but I must say I am not crazy about the looks of those either, although they are the original look of that engine.
Slotted screws look too much like sewing machine parts in my opinion, but to each their own.
I prefer the old style bolt look, which had a taller head than a new bolt.

View attachment 131301
But the sewing machine and the typewriter of two works of genius. How the sewing machine works by putting a loop over the bobbin is more complicated than an engine.
 

GreenTwin

Well-Known Member
Joined
Jul 2, 2021
Messages
343
Reaction score
206
Location
MidSouth
Nice engines, but to be honest, I prefer the look of your father's engine. Also, it would be an easier job to fabricate the base as I don't have any casting equipment, yet.

Where would be a good place to start a new thread for this? I'm seriously thinking of doing a better job on logging the work I do. Some of which is doing some pretty heavy reclamation of old CI scraps.

(Edited to change a word to something more appropriate)
My guess would be under the "ENGINES AND DOWNLOADS" banner, under the "ENGINES - Engines made by the member".

Good luck.
.
 

GreenTwin

Well-Known Member
Joined
Jul 2, 2021
Messages
343
Reaction score
206
Location
MidSouth
But the sewing machine and the typewriter of two works of genius. How the sewing machine works by putting a loop over the bobbin is more complicated than an engine.
I still don't understand how the loop/bobbin thing works, even when I am standing there looking at it.
Call me a dumbie or whatever, but I don't really get it.
.
 

Latest posts

Top