# Unimat Classic 1 - First Project - 4stroke Single



## Tomo1 (Apr 17, 2013)

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.....


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## Swifty (Apr 17, 2013)

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.


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## metalmad (Apr 18, 2013)

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


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## Tin Falcon (Apr 18, 2013)

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


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## AussieJimG (Apr 18, 2013)

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


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## Tomo1 (Apr 18, 2013)

Swifty said:


> 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


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## Tomo1 (Apr 18, 2013)

Tin Falcon said:


> 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


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## Tomo1 (Apr 18, 2013)

AussieJimG said:


> 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


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## Tomo1 (Apr 18, 2013)

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................


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## AussieJimG (Apr 18, 2013)

Tomo1 said:


> 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


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## /// (Apr 18, 2013)

AussieJimG said:


> 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)


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## Tomo1 (Apr 19, 2013)

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.


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## Tomo1 (Apr 19, 2013)

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..


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## parisharma1 (Apr 19, 2013)

Great and very informative post thanks for share.


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## Tomo1 (Apr 20, 2013)

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.....


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## Tomo1 (Apr 20, 2013)

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:


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## Swifty (Apr 20, 2013)

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

Paul.


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## Tomo1 (Apr 20, 2013)

Swifty said:


> 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.


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## Swifty (Apr 21, 2013)

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.


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## Tomo1 (Apr 21, 2013)

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 !


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## /// (Apr 21, 2013)

Water Jackets eh?
Sounds like you got the hang of 3D modeling pretty quickly


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## Tin Falcon (Apr 21, 2013)

I appreciate your enthusiasm on wanting design your own engine . IN my opinion if this is first build select a tried and tested plan set. 


Tin


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## Tomo1 (Apr 21, 2013)

/// said:


> Water Jackets eh?
> Sounds like you got the hang of 3D modeling pretty quickly



Was not as bad as I first thought it would be. Blamed the program several times only to find out it was the operator .

I have tried to keep the water jackets simple by them being basic drill holes.
I plane to plug these from the outside similar to welch plugs or use bolt/washer combo

 I will load a 3d image shortly and also a revised plans.

Not sure yet if the water cooling system will make the final cut but will keep everyone posted.


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## Tomo1 (Apr 21, 2013)

Tin Falcon said:


> I appreciate your enthusiasm on wanting design your own engine . IN my opinion if this is first build select a tried and tested plan set.
> 
> 
> Tin



Thanks Tin Falcon I Agree.

The time and effort spent on basic decisions such as bearings, piston sizes etc... Far out ways the end product. I would not recommend it.The chrome dome is losing more hair as we speak from frustration.

I am thinking of running a standard design project along side this one so as to gain experience and also have the confidence that it will fire up at the end. I will have a look around for some plans.  

In the meantime I plan to build a small pine model of the model engine on this thread  to verify design and also so parts can be trial fit. I hope that this will also allow me to sort any teething problems on the Unimat 1 / Chinamat1.

Thanks everyone for the advice and comments.


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## Tomo1 (Apr 22, 2013)

Hi Everyone.

Just a quick image of the cylinder block showing all the cooling passages and bolt holes. Trying to keep the machining side as simple as possible. Must remember though to measure, measure and then measure again before drilling

I will have some more detailed info up shortly..


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## Tomo1 (Apr 22, 2013)

Got around to thinking again (Oh No its a dangerouse thing!) and decided that the coolant passages were to small on my previouse block design. Also I was worried that they may cause the cylinder to warp due to the large gaps between them. Also the previouse design limited the length of the head bolts. So I have come up with a new design. This one negates the need for welch plugs in the block (Bonus) and also allows for the mahority of the drilling to be done from the top. The coolant passages also will be easier to mark out using a degree wheel.

I have two holes in the back of the block. The upper one is for the water pump and the second is an outlet. The transfer passages will now be located in the head. I will try and post some plans soon.

Have had a few delays on the Unimat but will also post some photo's and a reveiw shortly.

Any suggestions on how to improve the design are more than welcome friends!


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## Tomo1 (Apr 22, 2013)

Heres the revised cylinder head.

It should not be to hard to machine. The coolant transfer ports will be machined using a custom made swing table under the mini mill.(Fingers crossed.). Looks good in theory reality may be slightly different ... Ha Ha.


Any suggestions, comments and/or critisism more than welcome!!


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## anthonygm (May 23, 2013)

hi guys. just stumble apon this page. looks like you guys know what your talking about. if any of you can help me out i got two progects on the go i need a hand with. you can get ahold of me at [email protected]. who knows maby i can help you out


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## Tomo1 (Aug 15, 2013)

Sorry friends for not replying sooner....

Had a crazy busy  few months and a few unexpected work trips etc....

So a quick update on the Chinamat misadventure.....

Received the little pearler and excitedly but carefully assembled it. The first minus was the spindle which was bent and had 0.4mm run out. But after much refining and re-assembly (spent more time tinkering than turning but must admit it was rather fun.) with a little extra bracing was able to turn a 6mm aluminium rod down to a set size. The plastic tool holder though meant it had a rough finish. But even this improved after experimenting with different lubes with  light machine oil providing the best finish.  Found the mil was hopeless on anything but balsa. The wood lathe was very good for turning small fishing lures. and the Jigsaw provided my young nieces and nephews with lots of fun making small wood cut-outs.

But alas the it all came to a grinding halt when the little electric drive motor shaft wore right through the copper bush. Spinning the motor around 180 degrees (so the shaft pressure was against the opposite side of the bush) and a little less belt tension meant that it lived  through another 2 fishing lures before going out in a puff of smoke. Luckily a scrounge around found a motor about four times the original retrieved from an old lazy boy chair. To top it off it came with a worm gear on the shaft and another gear that fit on the spindle. The upshot was a decrease from 1500 rpm to only a couple hundred. The extra torque led to a lot better cut when turning allow rod. Alas the extra torque was to much for the spindle bearings.


If you are interested in a unimat 1 micro lathe it pays to go the dearer metal line type or the Chinese equivalent which have metal tool post, slides etc... (Such as the Shenzen z8000m/Unimat ML) But my suggestion is to look out for a old watchmakers lathe as they can be had for the same money! However for teaching kids woodwork and modelling (and getting the kids off the net) the Unimats are a good investment.

The chinamat may live on as I found a new engineering shop down the road with a cnc and they just happened to be looking for a small training project for the new guy. I may soon take delivery of a better spindle and end plate set up. But It will be mostly used for wood turning etc...

The rather good news is that our empty house in a small country town has after a year or so  and a 50% price cut found a new owner and the banks have to wait patiently till the next GFC to take the rest of our  possessions. So just maybe with a little thrift a Sherline or Taig could make an appearance on my lil work bench in our small granny flat rental in the city. 

In the meantime I will keep working on the engine design but run it under a new Thread!

Thanks everyone for your input and encouragement.


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