Brad93
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Does your VFD allow for wiring a two speed motor?
The problem as I would see it is most VFD ask you to choose RPM and Poles as a set variable.
- Thread starter Pete.
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The problem as I would see it is most VFD ask you to choose RPM and Poles as a set variable.
Pete.
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I'm not using the speed for switching Brad I want to re-wire it permanently for 4-pole 240v (just like a normal motor in delta).
Brad93
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Oh perfect yes that will work fine
Brad93
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You'd be asking a lot of an old? motor to get double the speed out of the 4 poles.
The TEC motors I've been using (cheap I know) are rated for 70Hz continuous over speeding. 120Hz for short bursts I believe.
Worst case though as you say put a new quality motor in that can be sped up to 100hz continuos.
The TEC motors I've been using (cheap I know) are rated for 70Hz continuous over speeding. 120Hz for short bursts I believe.
Worst case though as you say put a new quality motor in that can be sped up to 100hz continuos.
The fast rising edges of inverter drives can create havoc with older types of motor insulation, and at lower speeds the internal fan may not provide sufficient cooling.
it’s not entirely straightforward driving an old motor from an inverter, but most newer ones are designed to be ‘inverter compatible’
it’s not entirely straightforward driving an old motor from an inverter, but most newer ones are designed to be ‘inverter compatible’
I think almost all are as (copied from else where)
"From Jan 1st 2017, three phase electric induction motors with a rated output of 0.75kW to 375kW and efficiency less than IE3 must be equipped with a variable speed drive (Inverter Drive). For exceptions, see EC Commission Regulation 640/2009."
dobbslc
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That's interesting! It might explain why Kone lifts keep banging out our site temps with high earth leakage these last few years!
Bring back switch start motors!
dobbslc
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Kone lifts are asking for 500ma PER lift!
That's not possible on a big site as we can't get the discrimination back through the system to the mains!!!
They can't get it through their thick skulls the reasons we won't risk half a 50 story tower block tripping out due to their gear
That's not possible on a big site as we can't get the discrimination back through the system to the mains!!!
They can't get it through their thick skulls the reasons we won't risk half a 50 story tower block tripping out due to their gear
Last edited:
Pete.
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I haven't posted this week but that doesn't mean I haven't been doing stuff. The machine arrives tomorrow and I've been getting the last bits done on the attachments.
I painted the motor and belt guard on the high-speed milling head. I went for a VW silver because Ithought that it would be too much 'sea of green' if I made it all one colour. Not sure if I like it I will have to see it on the mill. I also connected the jumpers in the junction box for delta so it can run from a VFD, put a new piece of 4-core SWA on it and fitted the plug. The original wire was a bit of rubber 3-core wire and they used the earth for the 3rd phase leaving the motor with no earth protection. Now it's wired properly. The VFD will be housed in one of the electrical cabinets on the machine.
Yesterday I brush-painted the milling head and slotting head slide. It has come out passably well, no big runs and it will do for now. I expect I will be painting much of it againbecause no matter how carefully I handle the parts they are very heavy and the paint gets knocked.
Here it is part-assembled on the mount. I can't do any more because the cold weather means the paint is still soft and I know that fitting the clock spring is going to be a battle. I'll leave it a few days and do it next week.
I fitted up the slotting slide and it does now go full stroke. I took this photo to show the really dumb arrangement of having the oiling groove become exposed on the longer stroke letting the lube oil just run out. For slotting gear keyways it would be OK as they are short but anything over about 50mm stroke and the end of the groove gets uncovered. Dumb idea.
Slotting head all finished now.
Nice shiny parts lined up on the bench. Looking forward to the machine's arrival tomorrow (well, today now actually).
I painted the motor and belt guard on the high-speed milling head. I went for a VW silver because Ithought that it would be too much 'sea of green' if I made it all one colour. Not sure if I like it I will have to see it on the mill. I also connected the jumpers in the junction box for delta so it can run from a VFD, put a new piece of 4-core SWA on it and fitted the plug. The original wire was a bit of rubber 3-core wire and they used the earth for the 3rd phase leaving the motor with no earth protection. Now it's wired properly. The VFD will be housed in one of the electrical cabinets on the machine.
Yesterday I brush-painted the milling head and slotting head slide. It has come out passably well, no big runs and it will do for now. I expect I will be painting much of it againbecause no matter how carefully I handle the parts they are very heavy and the paint gets knocked.
Here it is part-assembled on the mount. I can't do any more because the cold weather means the paint is still soft and I know that fitting the clock spring is going to be a battle. I'll leave it a few days and do it next week.
I fitted up the slotting slide and it does now go full stroke. I took this photo to show the really dumb arrangement of having the oiling groove become exposed on the longer stroke letting the lube oil just run out. For slotting gear keyways it would be OK as they are short but anything over about 50mm stroke and the end of the groove gets uncovered. Dumb idea.
Slotting head all finished now.
Nice shiny parts lined up on the bench. Looking forward to the machine's arrival tomorrow (well, today now actually).
Pete.
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Moving day has come and the machine is now home. Big thanks to Bob for fetching it on his lorry and lifting it over the wall from the school grounds. The guy at the school said we should have waited 'till Easter then it would all be tarmac'ed over as the were making a new car park. We all tied in together to deliver my machine, take away the Herbert and transfer Brad's Beaver mill from the lorry to the trailer so it was a day well spent.
Only got one crappy photo as we were so busy and had a lot to do. Perhaps one of the other guys might have some pics.
Much better than dragging it up that alleyway
Only got one crappy photo as we were so busy and had a lot to do. Perhaps one of the other guys might have some pics.
Much better than dragging it up that alleyway
Brad93
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Just got in after blowout on M2. Safely delivered @Shiny Steve machine though once the spare was on, and then had to try 4 petrol tstations trying to find a pump.
Big thanks to @8ob, pleasure to meet you in person.
Big thanks to @8ob, pleasure to meet you in person.
Shiny Steve
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Thank you very much gent's. All sorted, in the end that when quite well apart from the tyre.
The little Herbert is now under cover until I clear a space for it in the workshop
The little Herbert is now under cover until I clear a space for it in the workshop
Pete.
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Okay, so I mixed up some of the degreaser reccomended by @8ob with hot water and jetwashed the living heck out of the whole machine. I wasn't too careful about where it all went because the electrics are all getting torn out so I just went easy around the motors but I basically got everything including the coolant sump in the base. The coolant tank filled up with some ugly brown greasy mush which I sucked out with my wet vac and gave it a couple more blasts through until it was clean.
After that I dumped a whole tin of Wurth's finest water displacer on it which is why you can see dirty streaks all down the machine here.
Plus I found the serial number and build date - 1960!
Once it was dried off I took some time to look over the ways and other bits. The table ways were a surprise because they showed extensive scraping marks. The scraping isn't surprising but the fact that it's still there after 62 years is! Worth noting that this machine doesn't have a knee it has what they call a console table. There's a narrow vertical slide that has horizontal ways for the console table. The machine table bolts to the console and as mentioned before you can swap and change the table for fixtures and stuff.
Apart from the scraping marks you can see the end of the tapered jib is still flush with the end of the dovetail - it's probably never been adjuster for wear because there isn't any.
The lower way looking down behind the screw in the above pic. There's some scoring on it which I presume is from trapped debris because this way is not carrying the table. I'll have to scrape that.
The other side is the same. The rusty patch isn't a working way so it never sees use - it's just a reference surface.
Lower way has some scratches in it that look like someone has used emery to remove rust or something. Definitely not wear.
Upper way which is carrying the weight of the table and doing the most work. Scraping is still faintly visible which is nice to see.
One reason why the table ways are so good is because it contains an oiling pump . You pull the plunger every once in a while and it pumps oil into the table ways. Normally these are sprung so you pull them out and the spring slowly pushes them back in, but this one doesn't appear to be sprung. I will investigate that when I service the table and vertical slide.
After that I dumped a whole tin of Wurth's finest water displacer on it which is why you can see dirty streaks all down the machine here.
Plus I found the serial number and build date - 1960!
Once it was dried off I took some time to look over the ways and other bits. The table ways were a surprise because they showed extensive scraping marks. The scraping isn't surprising but the fact that it's still there after 62 years is! Worth noting that this machine doesn't have a knee it has what they call a console table. There's a narrow vertical slide that has horizontal ways for the console table. The machine table bolts to the console and as mentioned before you can swap and change the table for fixtures and stuff.
Apart from the scraping marks you can see the end of the tapered jib is still flush with the end of the dovetail - it's probably never been adjuster for wear because there isn't any.
The lower way looking down behind the screw in the above pic. There's some scoring on it which I presume is from trapped debris because this way is not carrying the table. I'll have to scrape that.
The other side is the same. The rusty patch isn't a working way so it never sees use - it's just a reference surface.
Lower way has some scratches in it that look like someone has used emery to remove rust or something. Definitely not wear.
Upper way which is carrying the weight of the table and doing the most work. Scraping is still faintly visible which is nice to see.
One reason why the table ways are so good is because it contains an oiling pump . You pull the plunger every once in a while and it pumps oil into the table ways. Normally these are sprung so you pull them out and the spring slowly pushes them back in, but this one doesn't appear to be sprung. I will investigate that when I service the table and vertical slide.
Pete.
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I stripped off the axis scales and stops. The machine comes with three ways to measure the travel on the y-axis. The graduations on the handwheel, a scale on the slide and a gauge block holder with adjustable stop rod. You can also fit a dial gauge if you wanted instead of a stop bar.
The scale is on the left with a zero-mark that can be adjusted a short distance and locked with a thumbscrew. The stop bar on the right can be fitted into either of two holes on the mount, the bottom one will stop it against gauge blocks that you would put on the little ledge below, the upper hole will cause it to trip the auto-feed lever. The graduated handwheel is on the right with thou divisions that count in both directions on two separate scales.
The Z-axis also has a scalewhich is a vertical rod with thou graduations. It also has an adjustable zero-makr but this one incorporates a vernier scale. Also at the top is an adjustable clamp with a stop rod that can be swapped out for a dial gauge.
On the other side are the trips for the z-axis auto feed. These are adjustable same as x and y by loosening the tee slot and sliding them up or down. They added a second unused tee nut into the slot above the lower limiting screw I haven't investigated why yet. It might be a later addition to prevent over-travel.
The scale is on the left with a zero-mark that can be adjusted a short distance and locked with a thumbscrew. The stop bar on the right can be fitted into either of two holes on the mount, the bottom one will stop it against gauge blocks that you would put on the little ledge below, the upper hole will cause it to trip the auto-feed lever. The graduated handwheel is on the right with thou divisions that count in both directions on two separate scales.
The Z-axis also has a scalewhich is a vertical rod with thou graduations. It also has an adjustable zero-makr but this one incorporates a vernier scale. Also at the top is an adjustable clamp with a stop rod that can be swapped out for a dial gauge.
On the other side are the trips for the z-axis auto feed. These are adjustable same as x and y by loosening the tee slot and sliding them up or down. They added a second unused tee nut into the slot above the lower limiting screw I haven't investigated why yet. It might be a later addition to prevent over-travel.
Pete.
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I wanted to check out the gearbox and make sure that I didn't soak all the gears and bearings with the jetwash. I had to drain the oil out first. A surprising amount came out - a whole gallon exactly.
I took off the inspecton plate and could see the tide mark inside that was the top of the level. It was miles above the sight glass, not that you could see anything in the glass itself. The drain plug is the bottom of the tank, the middle of the sight glass should be the level and the top of the clean red paint mark was the actual level. At least it wasn't empty!
I popped the sight glass out and found the cause of the over-filling - it was full of black gunge.
Cleaned up and ready for fresh oil.
At first glace the gears look pretty good but I wanted a better look
I took off the inspecton plate and could see the tide mark inside that was the top of the level. It was miles above the sight glass, not that you could see anything in the glass itself. The drain plug is the bottom of the tank, the middle of the sight glass should be the level and the top of the clean red paint mark was the actual level. At least it wasn't empty!
I popped the sight glass out and found the cause of the over-filling - it was full of black gunge.
Cleaned up and ready for fresh oil.
At first glace the gears look pretty good but I wanted a better look
Pete.
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I had to remove the gearbox 'cover' the other side which houses the gear selector. After removing all of the cap screws it wouldn't budge - it was held on two dowels.
The dowels had a grub screw in them that you remove and screw in a m6 bolt to drift out the taper pin. I popped both pins out and the whole gearbox came out!
Such a good design you can pull the whole unit complete, do any servicing, set up the selectors and fit the whole thing back in the hole.
The gearbox and selector mechanism is allin great condition but there is one sloppy bearing in there so I am going to change them all.
The dowels had a grub screw in them that you remove and screw in a m6 bolt to drift out the taper pin. I popped both pins out and the whole gearbox came out!
Such a good design you can pull the whole unit complete, do any servicing, set up the selectors and fit the whole thing back in the hole.
The gearbox and selector mechanism is allin great condition but there is one sloppy bearing in there so I am going to change them all.
Pete.
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I pulled off the y-axis slide for inspection. Unlike a knee mill the y-axis is a large casting on top of the machine that slides in and out carrying the head with it. The benefit is that it can be made much heavier than your average knee mill table with large slideways plus just like the console table you can swap out attachments. First I had to pull the taper gib, it's held in by a single push-pull screw.
The gib is in good condition and is still showing some scraping marks in the centre. This is a good example of how you over-scrape the middle of a way to prevent them rocking when the ends wear. You scrape the middle a bit more and then when the ends wear down a bit it starts bearing more towards the centre. It also allows a reservoir of oil in the middle of the way.
Once the gib was out I had to release the leadscrew so the slide could come off. I just unbolted the bearing and wound the screw out. I also had to remove the nut before I could get the slide off, it just plugs in with a firm sliding fit in the carrier. Once that was all off the slide could be removed. Once again I was pleasd to see a lot of scraping still evident.
The ways on top of the machine also showing scraping marks. This will be easy to scrape back in needing very little work. Note the 2-way bevel box for the auto feed. The dogs have sqaure edges one way and ramps the other so it knocks itself out of gear when you turn the handwheel.
The gib is in good condition and is still showing some scraping marks in the centre. This is a good example of how you over-scrape the middle of a way to prevent them rocking when the ends wear. You scrape the middle a bit more and then when the ends wear down a bit it starts bearing more towards the centre. It also allows a reservoir of oil in the middle of the way.
Once the gib was out I had to release the leadscrew so the slide could come off. I just unbolted the bearing and wound the screw out. I also had to remove the nut before I could get the slide off, it just plugs in with a firm sliding fit in the carrier. Once that was all off the slide could be removed. Once again I was pleasd to see a lot of scraping still evident.
The ways on top of the machine also showing scraping marks. This will be easy to scrape back in needing very little work. Note the 2-way bevel box for the auto feed. The dogs have sqaure edges one way and ramps the other so it knocks itself out of gear when you turn the handwheel.
