Galloway question

[BobsModels]

Hi

I am building the 1/8 scale Galloway. I have a question for those who have built any of the scales of this engine.

The question is about the two collars that operate the govenor arm. Shellys prints have these machined in a very specific way with a recess in one collar and shoulder on the other that does not go into the recess. It is the same on all the drawings I have 1/3, 1/6 and 1/8. It appears to be a lot of machining for no specific reason. Why was this done?

I have a number of pictures of the full size and these two collars fit directly together at least from what I can see in the pictures.

My plan right now is to make them like the original looks. Any input would be appriciated.

I am in the end game and plan to post some pictures when I get this little guy going.

Bob

 

[chuck foster]

hello bob
i have built one of the galloways (can't remember the scale) i have attached a picture of the collars that i think you are talking about

as you can see in the picture one collar rides against the governor weight arm (the brass piece attached to the flywheel) and the other collar that runs on the first collar, has the lock off lever bolted to it (hope that makes sense)

if you need more pictures just let me know.

chuck

 

[BobsModels]

Chuck

Thank you for the picture. It shows my question exactly. The two collars are separated by a shoulder. There is also a recess in the stationary part and that shoulder sits on top of it. Why all the extra machining? What is the purpose of the recess and shoulder?

I have attached photos from two different full sized engines. If there is a shoulder it is in the recess.

Bob

 

[Jasonb]

Have a word with George Britnell, he has made most of teh scales for Linley Machine and has re done a lot of the drawings to correct errors.

There are posts on here about the builds.

J

 

[BobsModels]

I have redone all the drawings and am working with the current owners to take them over once I have a working model using the new drawings.

I have just finished redrawing the collars and have attached my version of the collars in a PDF. For those who have not used 3D PDF just open it as usual, move mouse over the figure and then click on the activate. You can rotate or whatever to look at the part.

Bob

View attachment Collars version 2.pdf

 

[Jasonb]

Have a read of Georges post about the collars on Smokstak, its the 1/3 scale engine but same principals apply.

http://www.smokstak.com/forum/showpost.php?p=594583&postcount=19

J

 

[BobsModels]

J

I have read all of Georges posts on both sites and they have been very helpful. I saw he had similar questions on the collars. I was just trying to find out if anyone knew why Shelly had designed the collars that particula way.

As George and others found, I too found many errors on the 1/8 drawings. One thing I found a lot were demensions that were off by a certain percentage was OK on the 1/3 but when you go down to 1/8th even .010 is big. That is why I redrew the entire engine in 3D. I could assemble all the parts and see clearences and easily see modifications. Especially since I could move the parts in motion mode.

I hope the new drawings will help anyone trying the 1/8th. The 3D views will apply almost to all the scales.

Now off to making chips


Bob

 

[gbritnell]

Hi Bob,
Galloways huh? Boy those things were a real project. I started with the 1/3, went to the 1/6 and have just finished the 1/4. Yet to be done is the 1/8. As far as the collars I like you looked at them and tried for the life of me to figure out why they were designed that way. I could understand if maybe it would help with friction or something but almost every other hit and miss engine I have built has one sliding collar on the crankshaft and they work just fine. For the Galloways I used the overall dimensions of the 2 pieces and made it into one piece. It seems to work just fine.
I redrew the drawings for the 1/3 and 1/6 for the fellows at Ministeam. Another fellow redrew the 1/4 drawings. When someone buys a kit now they won't have to scratch their head trying to figure out how to make a part. There were so many 'fit at assembly notes' that it was hard to tell what and when to make a part.
If you need any other particular information don't hesitate to ask.
George

 

[BobsModels]

George

I am down to the endgame. I need to finish the gov arm (90% done) the collars (tonight), and the ignitor trip (90%). Then will fit alltogether. Then Mixer ( I am going to try and make a working Lunk), muffler and gas tank I will be good to go. I am a bit slow but I have also been keeping all the new prints up to date as I buld the engine. I used the engine as an excuse to learn 3D CAD having used pencil and paper up until two years ago.

I have been communicating with the current owner and we agreed when I had a working engine from my drawings he would like to have them. So if you do not start your 1/8 for a bit you might be able to get the new drawings. Wish I had understood some of the ways I could have demensioned everything. I could have done relative demensioning and then by changing one parameter could have had drawings for other scales or at least one heck of a start. I have more time in the drawings than machining at this point.

Thanks to all for inputs. Now to get it done.

By the way George, did you ever try and time one to run "backwards" from normal hit and miss direction? The Galloway CAM was designed for easy reversal if you wanted to run a saw on the front. My plan is to get it to run that way and bulid a saw rig for it.


Bob

 

[Jasonb]

Bob if you have not seen them there are a load of photos of a 5hp saw rig at the following, I have the same thoughts for my 1/6th engine.

http://home-and-garden.webshots.com/album/88886243mzpsZq

J

 

[karlw144]

I'm also building a 1/8 scale Galloway (Shelly engine), probably 60% done, and have had lots of problems with the drawings. Although I'm making progress, I sure could use new, accurate drawings. Does someone here really have them available?
Thanks,
Karl

 

[gbritnell]

Hi Karl,
I have redrawn the 1/3 and 1/6 drawings. Someone else redrew the 1/4 drawings. To my knowledge nothing has been done with the 1/8th. I talked to the fellows at Ministeam today and they would like me to get started on the 1/8 castings and keep track of the drawing discrepancies for future drawings. You just can't take the drawings for the 1/4 and reduce it by half because of screw sizes etc.
gbritnell

 

[karlw144]

Hi George, ya lots of issues with drawings. As far as screw sizes,some real problems calling out tap drill size, when in reality he called out clearance drill size, guess what,now the hole is too big to tap,and next size larger screw looks like crap! Should have checked better before I drilled some of the holes.

Karl

 

[BobsModels]

Karl

I have virtually all the1/8th scale drawings redone. I gave a preliminary set to the fellows at Ministeam last spring.
At NAMES I showed them some format changes and they said they liked them and agreed I should have the engine running before I publish the prints to them. I should have the engine done next month with a little luck. When the engine is running, then the drawings are correct at least for one engine. Since the new drawings are the only ones I am using. As I am not a professional the drawings may have extra demensions on them but I am sure no one will care.

At this point I do not have an easy way to create a set for transmittal. I agree many of the hole sizes are incorrect. I changed lots of screw sizes to make it fit better. The ignitor was the first thing I did with my new drawings because the drawings were incorrect and at 1:1 I could not see the demensions on the print. Most of my prints are 2:1 or larger so I can see them.

Post a picture of how far along you are.

Bob

 

[chuck foster]

we all agree the original drawings have some problems : what i never understood was the cylinder liner.
if i remember right there is about 2 or 3 different steps in the o.d of the liner.
i think i just bore the water hopper casting out to one diameter and pressed in a straight liner.

can anyone shed some light as to why the liner o.d was stepped???

bob, hows the model progressing??


chuck

 

[steamer]

Probably to make pressing it in easier.. It only presses in the last little bit.

Dave

 

[stevehuckss396]

Probably to make pressing it in easier.. It only presses in the last little bit.

Dave

That would be my guess. I made the liners in my V8 stepped for that same reason. They drop in about 65% of the way.

 

[Jasonb]

All the steps are indeed sizes so most of the liner can be put into the casting and then presses home but there are more steps than there need to be, the raised one between the ignitor and water space could be done away with I should think.

J

 

[gbritnell]

When I built the Galloways I made the liners with only 2 diameters, a larger one up front by only .010 and the smaller one in the rear. That way I wouldn't have to press the entire length of the sleeve into the cylinder casting. The center area on the sleeve was relieved by .015. You just have to make sure that you have enough length on the front to seal the port from the igniter.
Trying to bore and counterbore into the cylinder casting with different diameters is totally unnecessary if you ask me. Actually for the 1/4 scale engine I bought a piece of Durabar iron and made the sleeve the full length of the cylinder casting plus the amount it projected from the rear. I made it about .0015 press fit with Loctite.

P.S. dont forget to drill the drain hole into the cylinder casting before pressing in the liner.

gbritnell

 

[karlw144]

Bob, I'm away from home for awhile, I'll try to post a picture next week. If you're coming to NAMES we could get together to look at your drawings, I'll be there the whole time, and easy to find. 2X drawings would sure help, I tried to draw some parts 10X and sit ll couldn't figure them out.

Karl