Unimat Classic 1 - First Project - 4stroke Single

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

 

[Tin Falcon]

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

 

[Tomo1]

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.

 

[Tomo1]

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.

 

[Tomo1]

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..

 

[Tomo1]

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!

 

[Tomo1]

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!!

 

[anthonygm]

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

 

[Tomo1]

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.