# Mechanical saw



## Chinggis (Jul 10, 2021)

I finally finish my long lasting project, Mechanical Saw No. 1 . And it works, what is surprisingly )). Well, there is some room for improvement, and I have a question. I use electric motor from car windshield sweeper. How powerful must be electric motor. Windshield sweeper work fine, but it make be hot after 10 minutes of work.


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## markba633csi (Jul 10, 2021)

Chinggis:  You may find the windshield motor not suitable for long periods of operation- they are not designed for high duty cycle
Have you a plan for applying pressure from blade to workpiece? Perhaps a sliding weight would be a good approach
Good job on the frame however! 
You might consider an ac motor and reduction pulley design as a future improvement
-Mark


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## hman (Jul 10, 2021)

Nice looking saw!  I'd agree with @markba633csi and say that a wiper motor might not be suitable.  Is there any way you can add a cooling fan?

Obviously, I have no idea what kind of supply situation you're facing in Croatia ... finding a suitable AC motor here in the US is pretty easy.  But an AC motor (at least 1/4 horsepower) with reduction pulleys would improve the performance of your saw.  Unfortunately, you'll have to do some more fabrication work to mount the new motor, pulleys, shafts, and crank if you go to a different motor.


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## mpoore10 (Jul 10, 2021)

Power hacksaws usually use a 1" tall blade to prevent it from wandering. The good news is that they can be found in similar lengths to manual hacksaw blades, so you could use it without modification.


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## mpoore10 (Jul 10, 2021)

Wiper motors are used continuously in Indiana many days of the year. Getting maximum cut will require weight that might be more than the motor can handle. Nice job. I am sure it beats the alternative.


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## Chinggis (Jul 11, 2021)

Thank you, all! 
I try with windshield sweeper  motor because I have them and I think it will be powerful enough for saw, but it is not and it will need more power. I can buy new or used one electric AC motor but it is expensive around 1000 Kuna(250-300$). I will try to find sweeper from truck, maybe it it have more power, if I am lucky to find it.


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## Bi11Hudson (Jul 11, 2021)

mpoore10 said:


> Wiper motors are used continuously in Indiana many days of the year. Getting maximum cut will require weight that might be more than the motor can handle. Nice job. I am sure it beats the alternative.


Agreed, from a different perspective. It is normal for a motor, any motor, to run warm. When you can lay a hand on it for 30 seconds, it isn't *too* warm. In all likelyhood, the load is just too much for the small motor such as what you have. A truck wiper motor may be the solution, it may take something larger. (higher HP) Decreasing the force required to move the saw may solve the dilemma. HP is torque times speed. . . Shortening the eccentric (stroke) may solve the problem.

.


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## NC Rick (Jul 11, 2021)

Chinggis said:


> I finally finish my long lasting project, Mechanical Saw No. 1 . And it works, what is surprisingly )). Well, there is some room for improvement, and I have a question. I use electric motor from car windshield sweeper. How powerful must be electric motor. Windshield sweeper work fine, but it make be hot after 10 minutes of work.
> 
> 
> 
> ...


 I Unequivocally applaud your ingenuity and imagination as well as your fab skill at taking an idea into a working machine.  Nice going not giving money to horrible fright too! I love it.


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## jwmay (Jul 11, 2021)

I think both iterations were great.  I wonder how well a leaky air cylinder would work. I think I saw one in  a dumpster I frequent.


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## Chinggis (Jul 12, 2021)

Good evening gentlemen s! 
Today I finally be able to make video and post it. And I got from my friend electric motor with ideal power and gearbox with right ratio . But, (why in all life there is this "but"?) gearbox is broken and I need to make some new gear and motor have a bend shaft. Is it possible to level out shaft. I see on my own eyes two attempts in company where I working, and both are, let me say politely unsuccessful. Right word will be with F..... .


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## Chinggis (Jul 13, 2021)

Yesterday I was not able to load video, today I make new one video and I post it. About motor, it will go into garbage, because someone is shorten its shaft and then try to weld it again.


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## budd1000 (Aug 21, 2021)

G


Chinggis said:


> I finally finish my long lasting project, Mechanical Saw No. 1 . And it works, what is surprisingly )). Well, there is some room for improvement, and I have a question. I use electric motor from car windshield sweeper. How powerful must be electric motor. Windshield sweeper work fine, but it make be hot after 10 minutes of wor
> 
> 
> Chinggis said:
> ...


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## herscheltaylor (Aug 22, 2022)

Chinggis said:


> Yesterday I was not able to load video, today I make new one video and I post it. About motor, it will go into garbage, because someone is shorten its shaft and then try to weld it again.


The result is amazing. Good job! It reminds me of when I made my first *mechanical reducer* prototype using a reference factory model. But the result was not as good as yours hahah


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## phubbman (Aug 24, 2022)

That is a great project.  
Maybe a motor from a clothes laundry machine could be found used.  Or a motor from an old treadmill.  People often use both on machinery.  If you find a DC motor from something like a treadmill, be sure to get the motor controller with it to convert AC electricity to DC, and maybe to control the motor speed.
Congratulations on your engine it’s and progress.  Best of luck with the rest of it.


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## FOMOGO (Aug 24, 2022)

If you can find an old wash machine at the dump, that motor would do the job. Nice work on the framework. Mike

Edit: phubbman, you beat me to it.


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