JonL
Elder Statesman
WWSME (Wiltshire)
Posts: 2,990
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Post by JonL on Dec 26, 2018 21:58:00 GMT
Might be a daft suggestion but it doesn't normally stop me... In the college workshop we had a fishtank air compressor which was enough to dust the swatf out the way when working, it had a flexible nozzle like a coolant hose.
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Post by Roger on Dec 26, 2018 23:34:56 GMT
Might be a daft suggestion but it doesn't normally stop me... In the college workshop we had a fishtank air compressor which was enough to dust the swatf out the way when working, it had a flexible nozzle like a coolant hose. I don't believe in daft questions, lateral thinking is often helpful! Although removing swarf is desirable, it's by no means essential. A small compressor is more acceptable than a big one though. Getting a little cutting oil in the right place is of more benefit in my opinion. |
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Post by ilvaporista on Dec 27, 2018 8:18:57 GMT
An idea I knicked from my fretsaw was a small air bellows pump. A wooden cam on the power feed motor depresses the bellows every rotation and gives a puff. It works best on cast iron with no cutting fluid. Sticky swarf needs a good blast to remove.
My coolant system is very basic but almost foolproof. Take two 5 litre plastic containers (mine are ex screen wash) drill a hole close to the bottom and fit a tap, mine are 1/4" BSP. On the other side of the tap use a push on or screwed connector to feed some 6mm plastic tube which runs to the delivery nozzle on the machine. From the drain hole in the machine run a tube which empties the used fluid (with a gauze filter) in to the top of the second container.
The feed bottle obviously needs to be higher than the delivery point, mine is on a shelf behind the machine. With all in place set the desired flow rate ( and here a screw down valve might be better than my ball valves) and off you go. Once the top container is empty just swap them round. The system is portable between machines, if you are feeling flushed multiple systems can be built, but I am a tight fisted soul...
You know I said almost foolproof? Well one day you will change the containers round and forget to close the tap. It will only be obvious when you step in a puddle of cooling fluid... I have a plan to make the handle on the taps bigger and a dedicated holding location for the bottom container. The handle of the tap in the open position would not allow the container to be located in the collection position.
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Post by andyhigham on Dec 27, 2018 9:54:00 GMT
Another thought on swarf clearing
A paint brush could be clamped say 100mm from the spindle. At selected parts of the program extra lines of code could be added to retract the tool and move the job past the paint brush sweeping the swarf away before returning
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Post by Roger on Dec 27, 2018 11:21:30 GMT
An idea I knicked from my fretsaw was a small air bellows pump. A wooden cam on the power feed motor depresses the bellows every rotation and gives a puff. It works best on cast iron with no cutting fluid. Sticky swarf needs a good blast to remove. My coolant system is very basic but almost foolproof. Take two 5 litre plastic containers (mine are ex screen wash) drill a hole close to the bottom and fit a tap, mine are 1/4" BSP. On the other side of the tap use a push on or screwed connector to feed some 6mm plastic tube which runs to the delivery nozzle on the machine. From the drain hole in the machine run a tube which empties the used fluid (with a gauze filter) in to the top of the second container. The feed bottle obviously needs to be higher than the delivery point, mine is on a shelf behind the machine. With all in place set the desired flow rate ( and here a screw down valve might be better than my ball valves) and off you go. Once the top container is empty just swap them round. The system is portable between machines, if you are feeling flushed multiple systems can be built, but I am a tight fisted soul... You know I said almost foolproof? Well one day you will change the containers round and forget to close the tap. It will only be obvious when you step in a puddle of cooling fluid... I have a plan to make the handle on the taps bigger and a dedicated holding location for the bottom container. The handle of the tap in the open position would not allow the container to be located in the collection position. I love that wooden cam and bellows, a good puff could clear most things. The only trouble with it is that swarf goes everywhere. I presume you're using pretty thin 'suds' type coolant? Coolant seems to get everywhere however hard we try to contain it. This is one reason why I'm thinking of using very small quantities, applied exactly where it's needed to about it getting thrown everywhere. I'll probably live with the swarf piling up, it doesn't cause too many issues and I can vacuum it up from time to time. |
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Post by Roger on Dec 27, 2018 11:24:32 GMT
Another thought on swarf clearing A paint brush could be clamped say 100mm from the spindle. At selected parts of the program extra lines of code could be added to retract the tool and move the job past the paint brush sweeping the swarf away before returning Now that's lateral thinking! I guess you could use the same concept but to bring the work to a vacuum head. I suppose you could just lift the head up clear of the work and then swing in a vacuum arm that would be set relative to the height of the surface. It could get interesting if it snagged up and failed to retract though! |
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Post by jon38r80 on Dec 27, 2018 11:31:34 GMT
you could use a cam squezing a pvc pipe to release a small amount of oil in the same way that some printers meter colours. Size of cam and rotation period could be altered to deliver smsll mesurable amounts of cutting oil.
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Post by terrier060 on Dec 27, 2018 11:36:33 GMT
A vacuum cleaner or vacuum pump does seem to be the best idea. I found using an air jet from the compressor just spread the swarf everywhere even though I have 3 sides protected. I have made a shield out of cardboard stuck on to the table with Gorilla tape. Easy to remove and adjust and stops all the swarf from getting on the bellows, jogger and keyboard.
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Post by Roger on Dec 27, 2018 12:20:09 GMT
you could use a cam squezing a pvc pipe to release a small amount of oil in the same way that some printers meter colours. Size of cam and rotation period could be altered to deliver smsll mesurable amounts of cutting oil. Hi Jon, That's a simple idea, but I think I'm going to need a way to propel the oil to the place it's needed. I suppose that could be done with a very small pipe and a quick rotation of the cam though. |
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Post by Roger on Dec 27, 2018 12:26:12 GMT
A vacuum cleaner or vacuum pump does seem to be the best idea. I found using an air jet from the compressor just spread the swarf everywhere even though I have 3 sides protected. I have made a shield out of cardboard stuck on to the table with Gorilla tape. Easy to remove and adjust and stops all the swarf from getting on the bellows, jogger and keyboard. I can see experimenting with a few 3D printed vacuum attachments that shroud the nose of the spindle. You can dream up all sorts of long bristled curtains that surround the work too, but that makes it hard to see what's going on. I like the idea of just an occasional turning on of the vacuum, that might work ok, but it's still noisy. In the end, I'll probably end up living with the swarf on the job. It's easy to get paranoid about keeping the area clean so it doesn't keep ingesting and re-cutting swarf, but for roughing, that's really not important. If you clean up before finishing, the last pass produces very little swarf and I've not found that to be an issue. |
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Post by terrier060 on Dec 27, 2018 12:42:32 GMT
There must be a way of using small puffs of compressed air to create a vacuum cleaner? I favour this because I don't like to keep switching on electrical equipment in case it effects the Tormach. Their instructions say it should have its own mains connection to the fuse box with no RCD device. Mine is just on the main ring main.
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Post by Roger on Dec 27, 2018 13:31:31 GMT
There must be a way of using small puffs of compressed air to create a vacuum cleaner? I favour this because I don't like to keep switching on electrical equipment in case it effects the Tormach. Their instructions say it should have its own mains connection to the fuse box with no RCD device. Mine is just on the main ring main. Hi Ed, There are 'air movers' available commercially in a large range of sizes so that's definitely achievable. I think it's worth exploring just how sensitive the Tormach is to interference, I suspect it's nowhere near as bad as you are lead to believe. I think I'd do a similar test to the one you were using for the repeatability measurements to see if the machine comes back to where it should. Then run a program that moves say 1 inch in X/Y/Z all together back and forth then try to upset it by turning on compressors and fan heaters, electric drills and hoovers. After you've done that a few dozen times, stop the machine and see if it goes back home. It will either still be running and in the right place or it won't. Once you've given it hell, you won't be concerned about it any more. |
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Post by Roger on Dec 27, 2018 21:24:57 GMT
This is how the hook looks on 1501, it's got a huge hole for the chain link which is why I've made that part slightly wider than scale to make is strong enough.  DSCN5611 by Roger Froud, on Flickr I decided to make a fixture that would hold the blanks both ways round and in two ways so I could machine the link hole radii and the hook faces.  20181226_182824 by Roger Froud, on Flickr The link hole radius was machined with a 3mm radius mill which has a 0.5mm corner radius. You can select that type of milling cutter from the library.  20181226_190954 by Roger Froud, on Flickr The same program is used, I just mirrored it in the X-axis.  20181226_201509 by Roger Froud, on Flickr The central screw is M3 and the one through the pin hole is M2. Between them, and the fact that the hook is in a pocket, it's plenty to hold it down.  20181227_113427 by Roger Froud, on Flickr Again, the same corner mill was used so that I'd get a decent finish. Since there isn't a lot of metal to remove, I've used the same cutter for roughing and finishing.  20181227_114928 by Roger Froud, on Flickr  20181227_121725 by Roger Froud, on Flickr  20181227_122642 by Roger Froud, on Flickr Here's they're rough off the machine with sharp corners everywhere...  20181227_201018 by Roger Froud, on Flickr ... and here they are with blends and appropriate radii.  20181227_211141 by Roger Froud, on Flickr |
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Post by delaplume on Dec 27, 2018 21:47:54 GMT
Hello Roger,
I'm loving the authentic "look" of the hook but would like to ask a question}---- Have you also incorporated the reducing thickness of the hook as measured from the slotted hole position when moving around to the tip ??
I can't quite make it out from the existing photos----- perhaps that's what that "staircase" effect is all about when roughing the hook ??
Surprising to think that anything up to 1,000 tons could be tugging on that in full size !!
Alan
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Post by Roger on Dec 27, 2018 21:55:16 GMT
Hello Roger, I'm loving the authentic "look" of the hook but would like to ask a question}---- Have you also incorporated the reducing thickness of the hook as measured from the slotted hole position when moving around to the tip ?? I can't quite make it out from the existing photos----- perhaps that's what that "staircase" effect is all about when roughing the hook ?? Surprising to think that anything up to 1,000 tons could be tugging on that in full size !! Alan Hi Alan, Yes, the staircase shows the roughing process which gives a flavour as to where the metal is being removed from. The bottom of the hook starts to become narrower as the curve progresses to the open part at the top where it's at its narrowest. I've blown up the best photos I have from the front to get an idea of how it looks on the real thing and I think it's pretty close. I've made the hole in the rear part slightly smaller than scale and I haven't been quite as extreme with the blend so as to preserve a bit more metal there. It's pretty massive, so I'm sure it's strong enough. I did contemplate making it out of Gauge Plate, but decided it didn't need the extra strength. I presume it's a forging in full size, but I suppose it could be a Steel Casting. |
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Post by delaplume on Dec 27, 2018 22:24:29 GMT
Hi Roger-- Forging is the preferred method .............Have a look at this}--- vimeo.com/272156179Don't forget to make provision for a bar coupler between the loco and the first truck ( probably your driving truck )....The use of scale couplings is decidedly a no-no for Public running... Alan |
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Post by Roger on Dec 27, 2018 22:36:41 GMT
Hi Roger-- Forging is the preferred method .............Have a look at this}--- vimeo.com/272156179Don't forget to make provision for a bar coupler between the loco and the first truck ( probably your driving truck )....The use of scale couplings is decidedly a no-no for Public running... Alan Thanks Alan, I'll probably lash up something that comes up from under the buffer for those clubs that require it. We run all our club locos with a just a chain at the Fetes. They've been doing it for decades without incident. It would be interesting to know what various clubs have to say about it. I would have thought that a scale coupling and additional safety chain would have been adequate? |
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don9f
Statesman
Les Warnett 9F, Martin Evans “Jinty”, a part built “Austin 7” and now a part built Springbok B1.
Posts: 961 
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Post by don9f on Dec 28, 2018 0:50:01 GMT
This is the sort of thing that we can use at our track....note I hadn’t finished it when this photo was taken. It was spark eroded from gauge plate by a fellow member. For steam locos and battery powered ones that do not have a deadman’s feature, there also has to be a safety chain attached to the first vehicle. All our trucks have clevis type drawbars with a 1/4 inch pin.  The type of “scale” screw couplings available from suppliers that I have seen are certainly not very strong and are not used at our track, but some do use a piece of commercial chain....but our trains are not long or heavy. Under steady running conditions, depending on gradients etc. the actual drawbar pull required is not that great, but the coupling must obviously be able to withstand the force required to accelerate maybe a heavy train plus importantly, withstand a “snatch” that can suddenly increase the force by many times. I’ve never measured these forces so can’t give any figures for models but recall from my BR day’s that diesel loco drawbar hooks and couplings were rated for a “pull” of 56 tons. These days they might be even more! Roger your hooks look very good, have you worked out a method of attaching them to the buffer beams? Cheers Don |
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Post by delaplume on Dec 28, 2018 2:24:13 GMT
Anyone who remembers the dubious art of "Fly coupling" loose coupled wagons in freight marshaling yards will certainly know just what a "snatch" is --- or more appropriately what it sounds like!!....Look lively Mr Guard.... here it comes !!
I should have clarified a point earlier on..... I meant that the use of loose chains within a scale coupling is a no - no......The adapter shown by Don is lovely !!
I was witness to a run-away train at the now-defunct Rugeley track..........Chrome-plated Brass chain had failed between loco and tender just after climbing the long bank and coming alongside the Steaming Bays, so the safety's were lifting with a 3/4 boiler, a full fire and 75% on the reverser..
Off it went like Cassanova on a Promise !!..........All the way down to the far end of the track and the Bob Moore Halt where 2 of our club members had stopped their train for smoke and a chin wag.....I shouted and waved both arms above my head but all they did was to wave back !!........and they soon stopped doing even that as around the approach corner like a Black Spanish Bull snorting Heroin came this 5" gauge Black 5 fully out of control.....
I heard the resulting "Smack" and witnessed the 5 trying to "maul" the last passenger truck.........Next week the owner of the 5 bought the front buffer beam along to show hoe 1/8" of frame steel had buckled under the onslaught !!
Fortunately it wasn't a Public day !!
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Post by Roger on Dec 28, 2018 9:11:31 GMT
This is the sort of thing that we can use at our track....note I hadn’t finished it when this photo was taken. It was spark eroded from gauge plate by a fellow member. For steam locos and battery powered ones that do not have a deadman’s feature, there also has to be a safety chain attached to the first vehicle. All our trucks have clevis type drawbars with a 1/4 inch pin. The type of “scale” screw couplings available from suppliers that I have seen are certainly not very strong and are not used at our track, but some do use a piece of commercial chain....but our trains are not long or heavy. Under steady running conditions, depending on gradients etc. the actual drawbar pull required is not that great, but the coupling must obviously be able to withstand the force required to accelerate maybe a heavy train plus importantly, withstand a “snatch” that can suddenly increase the force by many times. I’ve never measured these forces so can’t give any figures for models but recall from my BR day’s that diesel loco drawbar hooks and couplings were rated for a “pull” of 56 tons. These days they might be even more! Roger your hooks look very good, have you worked out a method of attaching them to the buffer beams? Cheers Don Hi Don, Thanks for sharing that, I really like that kind of idea that makes it impossible for the link to jump off. I'll probably do the same rather than have a separate link that has to be substituted in place of the hook. If you look at the back of the rectangular section, there's a 2mm hole which will take a piece of Silver Steel. The idea is to compress the spring on the back of the buffer and then slide the pin through. There's a retainer for the spring which has a recess to prevent the pin from sliding out once it's in place. I'll make that shortly |
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