Chainsaw gearbox Ural gear ratio

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Light weight and solid power combined with compact dimensions allow this “lumberjack’s dream” to be combined with an ice auger and a bicycle, a sawmill and a winch.
Anyone who can confidently work with a welding machine, an angle grinder, and, if necessary, can even use a lathe, can make interesting homemade products from a chainsaw with their own hands.

In this case, knowledge of the basics of design and drawing will be very useful, since the accuracy of all dimensions and quality of assembly are the main conditions for the normal functioning of a unit driven by a chainsaw.

Without going into technical details, we will consider the most interesting designs using it.

Options for homemade chainsaws

The first thing that comes to mind when you think about what can be done with a chainsaw is its use as a sawmill. Many developers had to split logs onto beams with this tool.

In this case, the log lies motionless and is neatly sawn along its entire length without wobbling or oblique seams. If you equip such a mobile carriage with four lifting screws, you can accurately set the thickness of the sawn timber.

A lightweight homemade snowmobile made from a chainsaw is more complex in design than a sawmill, since here you need to move the gas and clutch to the steering wheel, and also take care of the shock-absorbing suspension of the supporting frame.

To increase traction, a “traction” gear is placed on the caterpillar drive shaft, the diameter of which is larger than the size of the chainsaw drive sprocket.

There are usually no problems with the steering mechanism, since it is taken from a regular bicycle or scooter and modified so that the central axis moves the rods that turn the skis. The snowmobile engine power must be at least 5 horsepower, so it is better to use a Ural chainsaw for this purpose.

The winter line of homemade vehicles will be complemented by snowmobiles

from chainsaws, which are structurally simpler than a snowmobile. The driving force is provided by a large diameter screw, which directly rotates the gasoline engine.

Those home inventors who would like to make a backpack-type helicopter from a chainsaw should know the same thing. Such a machine will require not one, but at least two engines operating in a coordinated mode.

This vehicle is most often made for the sake of principle rather than practical use. The main driving force of its creator is the desire to test his strength as a mechanic and prove to others the original use of this cutting tool.

The basis for the design is usually my grandfather’s old Druzhba chainsaw and an equally ancient bicycle, with which you can carry out any experiments on converting the frame for mounting the drive.

Power is transmitted here through a gear pair using a bicycle chain, and the start of such a homemade product is reminiscent of preparing for cutting firewood.

Less common are more advanced models, the basis for which is a mountain bike equipped with reliable brakes and shock absorbers. This chainsaw moped is equipped with a gearbox with a gear ratio of 18:1 and a CVT transmission, which allows you to comfortably move on it at the speed of a regular bicycle.

This option for using a chainsaw is quite simple, since the task here is to transfer torque from the saw motor to the propeller. A homemade outboard motor does not need to install a transmission. For it you will need to make a reliable adapter on a lathe from the saw drive gear to the propeller shaft. The propeller can be used from a standard outboard motor.

It is difficult to make a full-fledged walk-behind tractor from a chainsaw due to lack of power and traction. But many home craftsmen were able to build a lightweight motorized cultivator based on it.

The design of such a machine is very simple: the motor rotates a pair of gears and transmits increased traction force to one drive wheel.

The chainsaw motor is no different from rotating the cutting chain or the auger mechanism of a snow blower. Here everything depends only on the design abilities of the creator and his ingenuity.

Using a Stihl chainsaw with a power of about 3 kW, you can easily build a good device for clearing an area of loose snow. To simplify the design, some craftsmen refuse to install wheels and use conventional sled runners.

The chainsaw asks for the sky

The most daring inventors have long been eyeing the possibility of using a chainsaw as an engine for an aircraft. However, this instrument is not strong enough to master airspace. Therefore, no one has yet succeeded in making a backpack helicopter out of one chainsaw.

This device is useful not only when building a fence or foundation from screw piles, but also during winter fishing, when you have to drill dozens of holes in thick ice.

A motor winch is a very useful device, because with its help you can not only easily pull out a stuck car, but also lift a heavy load to a height, pull a boat onto land or move a cut tree.

The camping power station is assembled on the basis of Ural or Druzhba chainsaws. It consists of a frame, an engine with a gear reducer, a control panel, a generator and connecting electrical cables.

Beavers are serious competitors of chainsaws in the wild.

, which in addition to self-sharpening teeth have other advantages)

How to adjust the device - saw operating instructions

Before you start working with a new chainsaw, it is necessary to carry out a number of activities, namely:

Depreservation should be carried out as follows:

wipe the lubricant dry with a cloth soaked in a gasoline solution from the external working surfaces of the engine, gearbox and the saw itself;
take out the candle and rinse it thoroughly in gasoline, dry it and install it in its place;
Take a clean cloth and wipe the surface of the ignition wire.

Chainsaw assembly

Chainsaw assembly

If you have already started to disassemble your purchase, you will definitely notice that the gearbox is located separately from the engine. So, let's start assembling our tool:

First of all, disconnect the frame parts by removing the screw;
install the engine, which must be placed in a vertical position on the crankcase cover (flange). Install the gearbox using the flange, after which connect the engine and gearbox with a clamp located on the frame.

How to start one - let's talk about that now...

First, you need to activate the switch that starts the ignition by turning it to the operating position;

Before starting the chainsaw, you need to pump some gasoline into the carburetor unit;

Next, pull out the choke;

Pull the starter (pulling type) with a sharp movement;

Remember, if you pull the starter slowly, the engine will spin up slowly, and this will increase the likelihood that the spark plugs will be flooded and the engine will not start;

And with all this, you need to warm up the spark plug, as this will allow the excess fuel mixture to evaporate.

This is clearly seen in the video:

In our other article, read more about how to start a chainsaw.

Homemade boat motor from a Ural 2 chainsaw.

Re: Homemade boat motor from a Ural 2 chainsaw.

kinder-L » Nov 14, 2011, 05:02 pm

YES.

Of course, I was sure that my idea would infect someone. But what if the elder ZUBBER himself. So it was not in vain that the inflamed gray matter did not give rest to playful hands.

The main thing is to get involved in the fight, and then we’ll figure it out

Never be afraid to do what you know how to do. Remember, the ark was built by an amateur. Professionals built the Titanic.

Re: Homemade boat motor from a Ural 2 chainsaw.

ZUBBER » Nov 14, 2011 6:17 pm

Re: Homemade boat motor from a Ural 2 chainsaw.

kinder-L » Nov 15, 2011 00:41

Yes, damn it, I know how much these bourgeois 5-horse things cost. If it were not for our socially disoriented duronomics of the nationally known consumer goods, previously with a creak, but the family budget would have withstood it. But now all that remains is to dream. True, there is another side - the crisis spurs thought processes in the inflamed gray matter.

And what kind of eyes do I now see in my fellow fishermen’s eyes when I say that I have assembled (albeit not yet completely) a 5 hp PLM. .

Societies › This is interesting to know. › Blog › Friday chainsaw crafts!

Light weight and impressive power coupled with small dimensions make it possible to combine this “lumberjack’s dream” with an ice auger and auger, a sawmill and a winch.

Noteworthy homemade chainsaw products will be made at home by anyone who can confidently work with a welding machine, an angle grinder, and, if necessary, can even use a lathe.

In this case, knowledge of the basics of design and drawing will be very necessary, since the accuracy of all dimensions and quality of assembly are the main conditions for the production activity of a unit driven by a chainsaw.

Without going into technical details, let’s look at options for more exciting designs with its implementation.

Options for homemade chainsaws

The first thing that comes to mind when you think about what can be done with a chainsaw is its use in a sawmill. Many developers had to cut logs into beams using this equipment.

Under such circumstances, the log lies motionless and is neatly sawn along its entire length without wobbling or oblique seams. If you equip such a mobile carriage with 4 lifting screws, then there is an option to accurately set the thickness of the sawn timber.

A lightweight homemade snowmobile made from a chainsaw is more difficult in design than a sawmill, since here you need to move the gas and clutch to the steering wheel, and also take care of the shock-absorbing suspension of the supporting frame.

To increase traction, a “traction” gear is placed on the track drive shaft, the diameter of which is not just the size of the chainsaw drive sprocket.

Chainsaw Ural

The Ural-2T Electron chainsaw is a mechanized and highly productive tool that is used for felling, bucking and sawing trees, and this tool can also be used for harvesting firewood.
The Ural chainsaw consists of several main assembly parts, which we will look at right now in this article. On this website https://stroivagon.ru we recommend reading the following articles:

Photo-1. Chainsaw Ural-2T Electron, device.

The gas-powered saw Ural-2T Electron consists of the following main assembly units:

1-Throttle control lever, 2-joint, 3-strut, 4-throttle cable, 5-fuel line, 6-fuel tank,7-stop button,8-muffler,9-engine,10-starter,11- protective casing, 12-cylinder, 13-gearbox, 14-drive sprocket, 15-nut, 16-saw bar, 17-tensioner, 18-saw chain, 19-springs, 20-driven sprocket. The chainsaw sawing apparatus is equipped with a power system and lubrication, which significantly reduces the friction forces that arise during operation when the saw chain moves along the bar.

Photo-2. Ural chainsaw engine.

The engine consists of several basic assembly units, which I presented below for clarity. Photo 2 shows the following details:

1-crankshaft, 2-crankshaft bearing, 3-connecting rod, 4-piston.

Photo-3. Other engine assembly units.

The piston is made of aluminum alloy and there are compression rings on it, which are installed in special piston grooves. Photo 3 shows the following parts:

1-crankshaft bearing, 2-crankcase, 3-ignition wire, 5-compression ring, 6-piston groove.

The piston with compression rings are located in a cylinder, for which there is a cooling system and an exhaust gas exhaust system (muffler). The engine cylinder is made of aluminum alloy, and the internal working surface is chrome-plated. To reduce noise during operation of the chainsaw, as well as to extinguish sparks, the engine equipped with a muffler. Photo 4 shows the following positions:

1-cylinder, 2-cylinder cooling system, 3-muffler.

Photo-5. Drive friction clutch.

The friction clutch of a chainsaw is made of two parts - the driving part and the driven part. The driving friction clutch is installed on the shank of the crankshaft. The following positions are indicated in photo 5:

1-friction clutch driver, 2-spring, 3-weight in the form of ring sectors, 4-crankshaft shank.

Photo-6. Driven part of the friction clutch.

The driven part of the friction clutch (hub) is installed on the shank of the drive gear of the gearbox.

Malfunctions of the Ural chainsaw and how to eliminate them

When repairing a Ural 2t chainsaw, it is possible to eliminate any faults, including replacing the crankshaft, piston system, etc. Let's skip major and medium-sized repairs, and consider minor ones, which any untrained user can do.

Starts and stalls: what is the reason

There can be many reasons. But they always start looking from the simplest:

The fuel tank is running low.
The air filter is clogged with dust. A mixture that is too rich enters the combustion chamber and there is not enough oxygen to burn it out completely.
The breather - a tiny hole in the gas tank cap - is clogged. A vacuum is created in the tank, and gasoline is not pumped into the carburetor. The breather is cleaned with a thin needle.
The fuel filter at the bottom of the tank is clogged. It is pulled out with a wire hook along with the fuel hose attached to its fitting. But before doing this, you should remove the fuel supply hose from the carburetor. If gasoline flows out of it in a full stream, then the breather, hose and filter are clean.
Carburetor misadjustment. The fuel supply adjustment screw (not idle speed) is unscrewed a quarter of a turn and changes in the operation of the internal combustion engine are checked. If it gets better, unscrew it another quarter turn. If it gets worse, they twist it back. In any case, you need to remember how much the screw was unscrewed or tightened. It is better to adjust with the engine running and warm.

Repair and adjustment of the carburetor from the Ural 2T Electron chainsaw are presented in the following video:

Further problems with fuel supply are more serious:

the carburetor holes, filters, and channels are clogged;
The carburetor membrane has become unusable.

Diagnosing these problems will require disassembling the carburetor.

For reference: the Ural 2t Electron has a KMP 100 carburetor. There is experience when instead of it they installed a carburetor from the Chinese Viper Activia moped and even from the IZH Planet motorcycle. The difference in the volume of fuel supplied to the combustion chamber is stopped by adjusting the fuel supply screw. According to reviews, the Ural 2t Electron works better than with the original carburetor. Non-original carburetors do not fit the mounting studs. They are installed through adapters made of thick gaskets.

Poor contact with the spark plug in the spark plug cap.
When the internal combustion engine is running, the cap heats up and contact deteriorates. The temperature of the cap is tested by touch only with the engine turned off.
With other problems with ignition, the internal combustion engine either does not start at all, or “fires” due to an adjustment failure.
The cylinder exhaust ports or muffler are clogged with carbon deposits.

At low speeds there are few exhaust gases; they only need to exit through a narrowed passage. When the speed increases, the passage is small and the engine chokes. For a visual inspection, remove the muffler or the entire cylinder head. Contaminated parts are soaked in gasoline or special complex solutions and cleaned.

Carbon deposits in the exhaust system, on the spark plug, and coking of the piston rings are the weak points of old chainsaws. Their fuel mixture is filled with 2.5 - 3 times more motor oil (type M8) than in modern chainsaws: 15:1 during break-in and 20:1 during continuous operation. This large amount of oil does not burn out and forms carbon deposits.

Saw chain jammed

Poor lubrication can cause some or all of the chain links to become stuck. The gearbox or clutch may jam due to heavy blockage or mechanism failure. The internal combustion engine does not have enough power to turn the chain and it stalls. They try to reach it by hand, if it doesn’t reach out, they look for the reason.

Won't start, but there is a spark

If there is a spark, problems in the operation of the ignition system can only be due to misadjustment. Spark in the Urals 2t The electron should flash when the piston has not reached T.M.T. 3.66 mm. If the fastening of the ignition unit is loose and it turns, the ignition is interrupted. It is checked by matching the two factory marks on the block and the body. If there is a spark and the ignition is adjusted correctly, then the reason is the above problems with the fuel supply.

No spark on the Ural chainsaw

The prefix to the name of the Ural 2t Electron chainsaw indicates that this model uses non-contact electronic ignition. The previous Ural saw had a mechanical breaker. According to reviews, the electronic ignition unit is one of the weak points of this chainsaw. Its thyristors and transistors are filled with a monolithic compound and cannot be repaired.

The unit often fails due to overheating and when the engine suddenly stops at high speeds. Therefore, it is strictly forbidden to turn off the chainsaw with the “Stop” button or by removing the spark plug cap at high speeds.

Carburetor heating device

Photo-7. Device for heating the carburetor.

The device for heating the carburetor consists of a carburetor-1, a casing-2, a gasket-3, a carburetor casing cover -4. In the cold season, the carburetor is heated using exhaust gases. In the case of operating a chainsaw in the warm season, between the carburetor casing and the gasket- 2, install an aluminum damper.

Photo-9. Engine cooling system.

The engine cooling system consists of an impeller-1 (cast on the flywheel), a crankcase cover-2 and a deflector-3. The system works as follows: With the impeller, when the engine is running, an air flow is created, which is supplied to the cylinder through a channel formed by the crankcase cover and the deflector, thereby thereby cooling it. Air is taken from the atmosphere through slots in the crankcase cover. The frame of the Ural chainsaw consists of a stand-8, a steering wheel with handles-1, a throttle control lever-5 and a gas tank-7. The frame and the steering wheel are connected to each other by a vibration damping device, which consists of a spring-2 and a hinge-3. On the lower part of the rack there is a clamp-4 with which the engine and gearbox are connected and secured. The gas tank -7 has a built-in fuel valve -6, which is closed if necessary (for example, to remove the carburetor). When using a chainsaw, the carburetor throttle is controlled by lever-1. The lever is located at the right handle of the steering wheel and the throttle cable-2 is attached to it. When adjusting the idle speed of the chainsaw engine, the position of lever-1 is set by screw-3 and secured with nuts-4.

Photo-12.Choke lever.

Opening and closing the carburetor air damper is done using lever-1. The carburetor is filled with fuel before starting the engine by pressing button-2.

How to properly break in a new Ural chainsaw?

During the first start-up, excessive loads are applied to the moving elements of the gasoline saw. To reduce the pressure on them and avoid premature failure, you need to run in the tool.

This procedure is performed in the following sequence:

First you will need to prepare a fresh fuel mixture. For Ural chainsaws, the proportion of gasoline and oil used should be 10 ml of motor oil per 1 liter of gasoline. The type of fuel plays an important role. It is best to refuel Ural chainsaws with branded AI-92 gasoline. In this case, you need to pay attention to the seasonality of fuel, since many gas stations offer customers gasoline with different properties for summer and winter;
Next you need to add oil to lubricate the chain. For this purpose, a separate tank is provided in the factory configuration of Ural chainsaws;
The operator should then start the saw engine and begin cutting thin branches. In this case, you need to work with the tool at intervals of 2–3 minutes at approximately 2/3 of its total power. Every 15–20 seconds, the saw engine should be idling. Thus, it will be necessary to produce 5–6 full tanks of the fuel mixture;
After this, you can move on to sawing larger wood. At least 2 full tanks of fuel must be used for this;
Then you need to start sawing large logs.

A short run-in of the Ural chainsaw should be performed immediately after each long period of inactivity of the gas-powered tool. This will reduce the risk of engine seizure and significantly extend the service life of its cylinder-piston group.