Wicksteed power hacksaw

I rescued one today, it was going into the skip.
I've been looking around it and it seems in very good order, a 2 horse 3
phase motor that stands testing with my AVO, and nice unworn bearings and
slideways. The oil pump lifts the arm if I spin the flywheel by hand and the
'creep' facility seems fine too. Tomorrow I'm off to purchase a 3 phase
socket and try it out!
However the coolant pump is a bit of a mystery to be. There's a link from
the crank eccentric to the pump piston that is AWOL. I can make one easily,
but wonder if it should maybe be adjustable so as to vary coolant quantity?
I wish I could take a look at a genuine one.
Also, I cant work out how the pump should work. There seems to be a total
absence of valves around the pump unit,(incorporated into the bottom of the
iron casting that is the coolant tank) and at the delivery end there appears
to be one ball bearing that has an inverted cup sitting on it. Does anyone
have any experience with these things and can suggest how it's supposed to
work? There seems very little stuff on the www about donkey saws, this
should be a very useful little (well about 1/2 ton!) tool when it's up and
running.
Julian.
Reply to
Julian
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Are you sure that the part you're talking about is the coolant pump? I have a Qualters & Smith power hacksaw, which I believe is fairly similar. Your description sounds much more like the hydraulic oil pump which raises and lowers the bowslide. Every time the pump's piston is pushed into the cylinder, it raises the bowslide slightly. This should happen on the return stroke. How quickly the bowslide falls depends on the rate of leakage that you control using a valve. If it's the hydraulic oil pump which is incomplete, the machine won't function without it.
I may be wrong here. I'm just guessing. But if you think I can be of more help, feel free to post here or to e-mail me at cdt22 AT cantabgold DOT net.
Best wishes,
Chris
Reply to
Christopher Tidy
Sorry, I skipped over the first part of your post. Obviously it's not the hydraulic oil pump. My apologies. I'm tired...
The Qualters & Smith uses a little vane or gear pump for coolant. It sounds like the Wicksteed pump is rather different.
Is your Wicksteed the one with the rounded front end? Glad you rescued it. Most of the old power hacksaws are great machines.
Chris
Reply to
Christopher Tidy
Thanks for the reply.
It has a hydraulic piston pump with two pistons, one big one small. One seems to provide the 'lift' for the return stroke and the other seems to be the one that powers the ''raise'' facility after cutting. I had to rebuild this pump because it was full of cack and not working well. It's now working perfectly and the saw blasts through RSJ material in double time. The two horse motor is a huge thing for its power - must be very old, but the machine is a brilliant bit of kit....
I'm now struggling with the coolant pump. As previously stated it is a piston pump driven by an eccentric on the end of the ''crankshaft.'' I machined up a bit of threaded bar to drive the piston from the eccentric and now when it pumps it tries to rival Niagara Falls and swamps the delivery cup and flex pipe. There must be a mechanism to regulate flow - it's not in the delivery system because that is intact, so I'm thinking that there must have been a mechanism to regulate piston travel?
Is anyone familiar with my old Wisksteed saw (weighs about 1/2ton) maybe has one lying around or knows of any machine shops or suppliers that would be happy for me to come along and take a look?
Cheers Julian.
Reply to
Julian
Sorry once again for the response I gave last night. I was tired and hurrying.
It sounds like the Wicksteed hydraulic pump is somewhat different to the Qualters & Smith pump. The Qualters & Smith pump has one piston and a valve (which is part of the piston which lifts the bowslide) which closes automatically when the bowslide reaches its lowest position.
When I was searching for a power hacksaw, I was told by a machine tool dealer that the Wicksteed and Qualters & Smith machines were of a similar quality, but that he thought the Wicksteed had the better hydraulics and the Qualters & Smith the better bow.
The Qualters & Smith also has a two-speed motor, which is why the motor is huge. I'm not sure if the Wicksteed motor is the same.
One thing to watch with the hydraulics is to make sure that the oil in the cylinder is of the right viscosity. My machine kept breaking blades until I discovered that the bowslide was falling too quickly because the oil wasn't viscous enough. It needs ISO 150 oil.
I've been thinking about your question today and the only way I can see to vary piston travel is to vary the eccentricity of the cam. The piston travel will be the same even if you change the length of the piston or connecting rod. Is there any way of changing the eccentricity of the cam?
If not, the "Niagara Falls" situation may be the way it's intended to operate. But it's difficult to judge without seeing it.
I'm intimately familiar with the Qualters & Smith hacksaw, but not with the Wicksteed. Is there any trace of the Wicksteed company to be found online? I found out that Qualters & Smith had become Birkett Cutmaster, and they sent me a very useful manual for my saw.
There were also at least three different Wicksteed hacksaws produced. Early machines had the front end supported on two legs. Later machines had a rounded front end. And the latest machines I've seen had a very angular appearance. What cutting capacity is your machine?
I did save a large number of pictures of power hacksaws while I was looking for one. I don't think they'll show the part you're interested in clearly, but if you want them, just let me know.
Best wishes,
Chris
Reply to
Christopher Tidy
The Wicksteed pump is a very elaborate affair. Two pistons, two eccentrics, a large rotary valve block, relief valves calabrated bleeds etc. A manual control that varies the speed the blade drops and a control knob, with ''drop, idle, lift and work'' functions. It's a fine bit of kit, these saws must have been very expensive in their day compared to the modern bandsaws and circular/chop saws.
My Wicksteed has a two speed gearbox, fast and slow (not surprisingly :-) )
The lid for the hydraulic tank says to use light hydraulic oil, so I've used some oil designed for digger hydraulics which seems fine so far. I notice that with mine the blade only drops when the machine is running, if you switch to ''work'' with it stopped the blade stays raised.
There doesn't seem to be. I'm wondering if there was a linkage something akin to the Stevenson linkage used for steam engine valves, travel could then be varied. I'm sure I could probably invent something but I'd prefer to replicate Wicksteed's design if possible - just for originality.
I've been looking all over the net and google images, I've not been successful finding an image. If I get a moment tomorrow I'll post a few pictures for you to look at. It's the design with front legs, I'm not sure what the cutting capacity is - that would be the length of stroke as opposed to the length of blade?
Julian.
Reply to
Julian
I uploaded a few pictures here:
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It looks like the vice opens up to about 8'' so I'm guessing that is the machine's capacity.
I'm particularly interested in comments regarding the coolant pump arrangement. I made a link from the eccentric to the piston with some threaded bar. Coolant delivery is far too much such that it floods the delivery upper chamber and cup and knocks the upturned valve cup off it's seat. Ideally I need to look at an original machine to see Wicksteed's arangement and how delivery was controlled.
Cheers Julian.
Reply to
Julian
I haven't seen one of these before (mine is a much smaller rapidor) but the angled pushrod 'looks' all wrong. Is there an anchor point at the same height as the eccentric but further along the machine ? Maybe the eccentric should move a roughly horizontal bar, and the pushrod couple to it vertically. So the pushrod movement would be reduced in proportion to the coupling point's position on that bar.
-adrian
Reply to
Adrian Godwin
I know what you mean, but I'm not sure because the pump piston bore is angled towards the eccentric - If the pushrod was vertical it would foul on the piston internally. Thanks for the thought though.
At the moment I'm working on the manufacture of a pushrod with a ''pogo stick'' portion in the middle - with a suitable spring I'm of the opinion that I can remove some of the travel from the piston.
Julian.
Reply to
Julian
Yes, it's the biggest piece of round stock that you can get in the vice (you can usually cut a larger piece of round stock than rectangular).
As far as I can tell from the pictures I have, your coolant delivery system, including the cups, is original. I presume the cups are intended to even out the flow, so that the coolant isn't supplied in a series of squirts.
In all but one of the pictures I have, the pump connecting rod is missing. Which suggests that perhaps it wasn't the best part of the design. But I've got one picture showing the connecting rod, and it looks like you've got it pretty much right. Here's the picture:
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Best wishes,
Chris
Reply to
Christopher Tidy
Incidentally, the two-speed 1 3/4 hp motor on my saw is even bigger than that. It's all relative :-).
Chris
Reply to
Christopher Tidy
Looking at that picture more closely I notice what look like tiny oil pipes on the bowslide. Presumably there's an oil pump somewhere in the machine?
Chris
Reply to
Christopher Tidy
That picture of yours either shows the ''posh'' version of my model or maybe a slightly later one, it seems to have an ''autolube'' system similar to a truck chassis. My saw just has oil holes for an oil can all with nice spring loaded lids.
Thanks for the picture, it's certainly the best one that I've seen so far on the www and shows the coolant pump arrangement up well.
Yes, I'm sure it is original, there's nothing to suggest that anyone has messed with it. The cups must be to even out the flow, however the lower cup is on a flexible mount so you can angle the thing in whatever direction you desire - thus giving the flex delivery pipe an easier time!
I'll let you know how I get on with it.
Cheers Julian.
Reply to
Julian
I modified the pushrod to incorporate a spring link:
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It seems to work fine now. When the pump is priming itself the spring hardly deflects and full piston travel ensures rapid priming. When coolant reaches the delivery NRV at the top of the pipe pressure rises and the spring deflects by about 1cm thus reducing piston stroke. Now I get a good coolant flow and the little cups don't overflow.
When I'm happy with the design I'll probably loose that cheap galv Screwfix threaded bar and use something that makes it look a little less codged together!
I'd still love to take a look at the genuine Wicksteed arrangement though - maybe I've improved upon the design?
Julian.
Reply to
Julian
Are they just holes, or do the openings go through to a reservoir? My saw has a hollow bowslide which forms a reservoir holding a couple of pints of oil. I didn't discover the reservoir until I got a manual. Probably the Wicksteed is different, but it's just a thought.
Chris
Reply to
Christopher Tidy
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It looks like you've come up with a perfectly functional solution. Just one more thought, though: is there any chance there was a porous element of some kind in the top cup, maybe a sponge or a mass of metal wool or something, to smooth out the flow?
Best wishes,
Chris
Reply to
Christopher Tidy
I would suggest skimming the tramp oil off the top of the suds in there before too long.
regards Mark Rand RTFM
Reply to
Mark Rand
Dare I ask why? I thought it made the surface of the coolant look rather pretty :-)
Julian.
Reply to
Julian
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The flow is smooth now, (well enough as makes no odds) I'll see if I can do a little video of it working this weekend if I find a minute.
Julian.
Reply to
Julian
You could well be correct, the thought hadn't occurred, I'll have a good look, cheers.
Julian.
Reply to
Julian

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