Unimat Classic 1 - First Project - 4stroke Single

[Tomo1]

Hi Everyone....

Just new to this site and machining in general. (Apart from metalwork in highschool/)

I have been for a while been planning a small v8. Decided to take a small step first and test the design as a single cylinder then go from there. Only problem is that that my workshop is in storage while we are at the in-laws for a few months. The only area I have is a 2.5x2.5m room which is also my office for work.

So to keep mess and noise to a minmun I have recently aquired a chinese version of a Unimat Classic 1. I understand that I am most likely in for a world of hurt with that one :wall:. But for some strange reason am looking forward to the challenge. At least I can get started on the engine...

Would be interested to see if anyone else has had experience with a Unimat1?

As soon as i get some photo's of the initial engine parts I will get them posted.....

 

[Swifty]

Hi Tomo1, welcome to the site, where about's in Australia do you live? I'm keen to see your design for the single cylinder engine. I'm planning to start one soon as well, just have to get the design from my head onto cad so I can make a start.

Paul.

 

[metalmad]

Hi Tomo
Welcome to the forum Mate!
Good idea with starting slow, do a single or two and a twin, then have a crack at the V8
It will take a few Engines just to work out what equipment you will need and to build up a little skill for the big one ;D
Pete

 

[Tin Falcon]

Her is a classic engine designed for the unimat and similar size engines.
http://www.john-tom.com/MyPlans/SteamPlans3/RiverQueenEngine/RiverQueenPlansInstruction.pdf
Tin

 

[AussieJimG]

Welcome Tomo, I am interested in your experience with the Chinese copy of the Unimat; I think I need a tabletop system for the cold weather.

Jim

 

[Tomo1]

Hi Tomo1, welcome to the site, where about's in Australia do you live? I'm keen to see your design for the single cylinder engine. I'm planning to start one soon as well, just have to get the design from my head onto cad so I can make a start.

Paul.

Hi Swifty

I live on the Gold Coast. Just moved back from Tin Can Bay. It was a nice place, mainly retiree's and the like. Never seen so many mini workshops in one area. Everyone was building model planes, trains, boats and some even there full size equivilents...

Jamie

 

[Tomo1]

Her is a classic engine designed for the unimat and similar size engines.
http://www.john-tom.com/MyPlans/SteamPlans3/RiverQueenEngine/RiverQueenPlansInstruction.pdf
Tin

Thanks Mate...

What a fantastic little engine. Actualy saw a similar truck as the one in the picture the other day on you tube. Willhave to post it if I can find it again.

This looks like a good starting project..

Tomo

 

[Tomo1]

Welcome Tomo, I am interested in your experience with the Chinese copy of the Unimat; I think I need a tabletop system for the cold weather.

Jim

Will let you know mate once I have it running.

Ive givin away fishing when its cold..... so am looking forward to tinkering away 2 during winter.

I researched it alot and feel the Unimat 1 Type lathes are great for what they are built to do (ie.. Micro components.). I think a little patience will go a long way with it.

Also I have been told that the Chinese ones come with more parts as standard and are of a better standard then the European ones - That would be a real turn up for the books.

Google Xendoll - They make a range of CNC mini lathes like the Unimat 1 -- Mmmmm if only I could find one of those

 

[Tomo1]

Yes . . . Scored a day off work. . . ( the finances wont like it )

Now to Finnish the design on my engine. I will try and post the rough plans this arvo. ( by rough I mean google sketch up...) Anyone know of a good free CAD program?

Have also been thinking (Dangerous Thing to do) that I may make a wood mock up of the block and heads so that I can sort the order to do things in as it is going to be right old challenge on the chinamat1 lathe.

Now to stop dreaming and start doing................

 

[AussieJimG]

Yes . . . Scored a day off work. . . ( the finances wont like it )

Anyone know of a good free CAD program?

Alibre is not free but it is reasonably priced - the Personal Edition is about AUD199 and does everything I need. It is 3D and very easy to use and with good tutorials and online forum help. Drawing an item in 3D helps to figure out how to make it, and the 2D drawings are done at the press of a button for all views including isometric. And you can have the dimensions included on the drawing automatically as well.

And best of all is that you can have the full package - bells, whistles and all - for 30 days for free. Just Google Alibre and download it.

It could be worth a try.

Jim

 

[///]

Alibre is not free but it is reasonably priced - the Personal Edition is about AUD199 and does everything I need.
...
Jim

Alibre Design 2013 has just been released and there have been changes made to the $199 PE version. At the time of writing, changes to 'Pro' and 'Expert' versions have been posted to their website(not many - sheet metal has been removed from 'Pro' and is now 'Expert' only) but any changes for the PE edition have not yet been made official and the website no longer has the 'feature list' available for PE.
I have read a vague reply by one staffer on the Alibre forum that PE no longer has 2D drawing and/or publishing. Bummer.

Also, it is no longer called Alibre Design.
3DS (3D Systems) acquired Alibre a while ago and they just recently acquired another company called Geomagic.
This is great for the software development side of things but sadly, in all 3DS's wisdom.... Alibre Design is now called Geomagic Design.
To say there are a lot of unhappy people is an understatement.
The biggest problem Alibre customers have with the name change is how un-professional and 'kids toy' it sounds.
I can admit that it has taken me a while to get my clients used to hearing 'Alibre' instead of Inventor or Solidworks.... but now when I am asked which package I use I have to tell them 'Geomagic' .... urgh
Many long time users are requesting it be changed to GeoMetric or simply shortening it to GeoDesign or something else a little more 'grown-up'.

Anyway, namechange aside. Alibre/Geomagic is very capable 3D modeling software. I also use Inventor at work and actually prefer Alibre for many reasons, one of which, I find it easier to use and more intuitive than Inventor.

Edit:
Keep in mind that the PE edition has very limited Save/Open/Import/Export filetype support. This may or may not be an issue for you.
Alibre... Geomagic (urgh) 'Pro' version is very feature rich and costs approx $1000 which sounds like a lot until you compare it to other software(Inventor/Solidworks/Rhino) with similar features (~$5000)

 

[Tomo1]

Thanks for the help on the CAD side of things. . Alibre looks good. Will give it ago.

Have now completed basic engine layout. Would like to use external pushrods and have a viewing window for the cam just for the visual effect.Also will try and keep it to around the 10cc mark. Will use glow plugs and have a semi functioning water cooling system. It will be interesting to see what actually makes it from this list on to the final version.

Now to finalise the dimensions and Ratio's - Will have to try and remember all that high school maths.(and I thought I would never use it.

 

[Tomo1]

Finally after several work related interuptions a basic blueprint to finalise the dimensions.

Apoligies for the grade seven style drawings...

Looking at a 9.6cc (2cm bore x 3.06cm stroke) external cam, pushrod engine.

Thinking of either using timing gears or nylon gears and a toothed belt (similar to small rc drive belts.) to drive the cam. Roller bearings for the crank and also possibly for the bigends to simplify the oiling side of the equation.

Thinking of using a press fit crank as I wont be able to offset grind a crank on the Chinamat1.

Alot more work still to go into the head/valve/intake design etcetc..

Ideas and suggestions more then welcome everyone..

 

[parisharma1]

Great and very informative post thanks for share.

 

[Tomo1]

Spent the arvo drawing up a CAD plan. Had the 3d model coming along aswell till the free 3d converter spat the dummie Ah well I suppose that's why it was free.

I'll put the more detailed plan up soon. Oh and it's now been bored out to 14.6cc with a shorter stroke.

Was Thinking of using no piston rings - but thanks to everyone's great feedback to my thread on that topic Im thinking that I will be pushing it on this model as I will be using aluminium as the unimat 1/chinamat1 can't handle steel. The consensus on the ringless piston is that it would have to be steel with a steel liner due to softer metals expanding more with the combustion temps.

Hmmm I used to have enough trouble putting rings on the full size 350 chev at work Might have to make make 3 or 4 ring sets to be on the safe side.....

 

[Tomo1]

A little more progress.. Heres a sectioned front veiw just to get a sense of the layout.

Comments, Suggestions and critisism are more than welcome!

Already noticed one error. The piston has grown to 25mm to get a reasonable compression ratio, but the Chinamat1 lathe only has a 20mm max jaw... Hmmm might need a mate to machine down the bar?:hDe:

 

[Swifty]

Keep in mind that on a 4 stroke, the gear ratio is 2:1.

Paul.

 

[Tomo1]

Keep in mind that on a 4 stroke, the gear ratio is 2:1.

Paul.

Thanks Swifty.

I surely messed that up. (It made sense at the time ..Hmmm now I know why I failed year 10 maths.. 44/30 does not equal 2. I also have the big pulley and the small pulley around the wrong way.. (Sheesh my wife picked that one up and she's never seen an engine before..) What a rookie!.

(Would have got very interesting if Swifty had not picked that one up. Hi valves let me introduce you to mister Piston several times each cycle...):hDe:

Thats what I like about this forum. Everyone is hepful and not afraid to offer suggestions etc..

Amended plan will be coming up soon.

 

[Swifty]

Was too concerned about the gear ratio to notice that the gears were the wrong way around. Might be best to have your wife give any changes a quick look over.

Paul.

 

[Tomo1]

My wife agrees with that!

Been toiling away on a revised set of plans.

Have found that the 3d modelling is very helpful in locating things in getting the placement of components right. The cylinder head is starting to look like it has a bad case of metal borer worm. Maybe it was not such a good idea to try and incorporate water jackets !