Author Topic: Titivating a Warco Mechanical hacksaw!  (Read 2183 times)

Online mattinker

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #25 on: February 10, 2017, 12:15:58 PM »
Well done Matthew, but i want the mobility scooter.  :drool:  :lol:

Thanks Biggles, for the mobility scooter, you'll have to contact AdeV for that

Offline awemawson

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #26 on: February 10, 2017, 12:50:30 PM »
Matthew, I vaguely looked into this about 15 !years ago - I saw a very similar Taiwanese saw in a used tool dealer, and there was a knurled knob on the end of a shaft emerging from the hole in the top plate that you used as a jig for drilling

I suspect that there was a ball valve similar to yours, but with something pressing on the ball to give a controlled leak. If you think about it, if your ball valve is perfect, the blade will never descend ! The little cylinder just transfers enough oil into the bigger one to lift the blade off the cut on the return stroke, but re-admits in on the forward stroke controlled by the timing of the cam.

Happy experimenting
Andrew Mawson
East Sussex

Offline awemawson

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #27 on: February 10, 2017, 12:58:39 PM »
Here you are Matthew, a picture is worth a 1000 words  :lol:
Andrew Mawson
East Sussex

Online mattinker

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #28 on: February 10, 2017, 02:06:12 PM »
Matthew, I vaguely looked into this about 15 !years ago - I saw a very similar Taiwanese saw in a used tool dealer, and there was a knurled knob on the end of a shaft emerging from the hole in the top plate that you used as a jig for drilling

I suspect that there was a ball valve similar to yours, but with something pressing on the ball to give a controlled leak. If you think about it, if your ball valve is perfect, the blade will never descend ! The little cylinder just transfers enough oil into the bigger one to lift the blade off the cut on the return stroke, but re-admits in on the forward stroke controlled by the timing of the cam.

Happy experimenting

That is what I'd thought, but, there were no traces of anything in and around the hole, no threads, no signs of anything! The one thing that is certain, a ball valve is required to allow the oil in. The small piston rises and falls, pressurising the large chamber raising the blade. The cam then allows the blade to lower, by venting partially the large cylinder through the port in the small cylinder. that much is clear, the thing that is not clear for me, which may have to do with the nob is lowering the blade down to the working position!

The photo is not very clear! I just found this!

<a href="http://www.youtube.com/watch?v=mPyXDhgrW0Y" target="_blank">http://www.youtube.com/watch?v=mPyXDhgrW0Y</a>

Regards, Matthew

Online mattinker

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #29 on: February 10, 2017, 02:35:23 PM »
Andrew, I've also found a thread on an older structurally the same saw that appears on a thread here

http://madmodder.net/index.php?topic=3483.msg37356#msg37356

I've sent him an email, so I hope that the person is using the same email adress now!

Regards, Matthew

Offline awemawson

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #30 on: February 10, 2017, 02:43:13 PM »
Interesting !

The adjusting knob shows up quite clearly on several of his pictures
Andrew Mawson
East Sussex

Offline awemawson

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #31 on: February 10, 2017, 03:35:17 PM »
At a conceptual level you need a needle valve in parallel with your ball valve introducing a 'controlled leak' adjusted from a rod though the hole in the lid. How you implement it might be a bit more complicated.  :scratch:
Andrew Mawson
East Sussex

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #32 on: February 10, 2017, 04:16:52 PM »
Thanks Andrew, I can see a way of doing it, a needle that can apply pressure to the ball valve from the top. I need to experiment when I get it back together. There is one thing that I need to confirm before I do anything else, it's the flow of oil when the saw is on the cutting stroke. On the return stroke, the small piston goes down, sending oil to the big piston pushing up the arm. When the blade reaches the end of it's stroke, the cam allows the small piston to rise (under pressure from the weight of the arm pushing the piston down) uncovering the port on the side of the small cylinder (it's about half way up) which lets the oil out of the large cylinder allowing the arm to drop, the port is open throughout the cutting stroke. At least that's what I can see so far! The saw in the video doesn't have anything on the to of the cover. I've written to the poster in the Madmodder's thread on rebuilding the mechanical hack saw, it would be easier to have something concrete to work from!

Matthew

Offline awemawson

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #33 on: February 10, 2017, 04:54:56 PM »
The one in the video doesn't have the hole in the lid like yours - obviously an inferior model to your top of the range one  :lol:
Andrew Mawson
East Sussex

Offline 2nd Opinion

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #34 on: February 11, 2017, 05:42:00 PM »
That's a great find.


Sent from my iPad using Tapatalk

Offline krv3000

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #35 on: February 11, 2017, 05:47:55 PM »
brill nice to see the compact 8 in youse

Online mattinker

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #36 on: February 11, 2017, 06:00:41 PM »
2nd opinion, well, it was a really great gift from Andrew Mawson, I'm pleased to have it, looking forward to it running!

Krv, The compact 8 is really useful, it's in really good shape, it was missing the motor when I got it, it came out of a school, apparently the kids had deliberately locked the motor an left it running and burnt it out. It still had the "cosmolene" on the bed ways! It's a real complement to my other big lathes!

All the best, Matthew.

Offline krv3000

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #37 on: February 11, 2017, 06:11:14 PM »
well its a sham you is not in the uk as I have a motor

Online mattinker

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #38 on: February 11, 2017, 08:43:04 PM »
Thanks Krv,

Thanks for the offer, I have a three phase motor (from a V10 Emco I think) that cost me 70 shipping from Australia! It's a three phase, two speed that I mounted with a three to one reduction on a lay shaft with a toothed timing belt. I Also put a 1 to 1 gearing option, which I've never used as I've never needed it! It'll run  as slow as 33 RPM which I find great for threading up to a shoulder!

Thanks again, Matthew

Offline krv3000

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #39 on: February 12, 2017, 12:09:31 PM »
brill that's the one thing I don't like is its slowest speed is not slow inuf for thread cutting on the standard lath 

Online mattinker

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #40 on: February 12, 2017, 06:30:00 PM »
 :thumbup: :thumbup:

Online mattinker

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #41 on: March 29, 2017, 04:14:19 PM »
I've been a little distracted recently, too much going on! In this video, I fix a problem with the non-return vale sticking!

Something wierd happening with the sound, looks out of sync and slow!!

All the best, Matthew

<a href="http://www.youtube.com/watch?v=eUmHhBcPrr0" target="_blank">http://www.youtube.com/watch?v=eUmHhBcPrr0</a>

Offline awemawson

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #42 on: March 29, 2017, 05:24:12 PM »
Good progress Matthew  :thumbup:

In the good old days, motor cycle oil pressure relief valves were just a ball bearing pressed by a spring against a cast iron bored hole. The received wisdom (written into maintenance handbooks) was to put a bronze drift against the ball, and give it a firm clout with a hammer, thus deforming the seat to the sphericallity of the ball. Those of us without bronze drifts used a steel rod, then replaced the ball bearing with another identical one, and it seemed to work splendidly. (no lapping allowed as the oil galleries would become contaminated)

Andrew Mawson
East Sussex

Online mattinker

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Re: Titivating a Warco Mechanical hacksaw!
« Reply #43 on: March 29, 2017, 05:33:34 PM »
Well, I wasn't sure whether it was the seat or the walls of the valve hanging things up, this way I was able to cove both!

More adventures to come!

regards, Matthew