01-09-2013, 09:34 AM
Hi,
What a busy week I've just enjoyed. I already had a stock of heavy gauge steel sheet so decided to use some of this to make a new metal enclosure for the VFD in order to separate it from dust and debris. This steel sheet was too thick to cut with tin shears and after a couple of cuts had been made on the big Startrite bandsaw the band started to complain as it was shedding teeth. Not wanting to use a hacksaw I resorted to using the angle grinder which is my least favourite power tool but its effective; with ear muffs and gloves worn for protection the grinder produced a big display of red hot sparks.
The sheets were large enough to cut down for each panel but not large enough to bend so an angle iron framework was cut and welded. I used offcuts throughout; the front frame was made from 1" angle the rest from 1.5" angle. Care was taken to align the angle iron during welding and making the frame was a time consuming job. Each panel in turn was fully welded to seal all the joints. I was making it up as I went along; the manual gives minimum air spacing for the VFD so anything larger would be acceptable; I knew I wanted the enclosure to have some kind of air filter to the bottom and at first I considered adding a simple sheet filter but left this alone whilst I gave it more thought. The top of the enclosure would be openly vented but covered by an extended cowl; this cowl would allow the VFD fan to exhaust warm air freely but prevent dust and debris from entering the enclosure. The cowl was made 1/2" larger all around but also would have a 1" deep lip folded so the cowl was cut out an extra 3" longer and 3" wider than the enclosure top in effect I was adding the cowl which would be raised 1/2" using machine screws and nuts for simplicity. I copied the cowl idea from the drip proof cowls which used to be fitted to some motors.
The dimensions I settled with are; 16.5" maximum height; 10.5" wide and 8" deep. The cowl dimensions 11.5" x 9.5" plus an extra inch all around for the folded lip height excluding the filter.
The welding was straightforward but a bit time consuming using my 140A SIP arc welder. With the welds completed the angle grinder fettled the joints. All during this I kept thinking about how to filter the air supply to the VFD and was even thinking about this in bed at night then suddenly it occurred to me to use a car engine air filter? I browsed eBay for a suitable filter and at around £8.50 each they were cheap enough but I thought why not pop into our local auto accessory store? Visiting the store I bought a nice big air filter for under £6 so all I now had to do was to install it. This sounds easy enough but how the heck can I cut a large hole in a thick sheet of steel? After considerable thought I remembered I had recently bought a brand new Erbauer jigsaw which came with a selection of blades including metal cutting blades so I thought I'd give it a try? I drilled a hole in the waste to accept the blade and was amazed just how easy it was to cut the large hole with the saw set at number two on the speed control; a file cleaned the edges of the hole so now I needed means of securing the filter.
Having lathes is a huge asset and I soon turned an 18mm thick MDF air filter base support adding a location rebate; the support was turned at maximum diameter to suit the diameter of the filter and the rebate was turned to suit the inner diameter of the filter thereby locating it in position; a central hole was added at 6mm clearance. A steel square off-cut was cut to length and tapped on centre at 6mm this in turn was tack welded to the inner bottom panel. Next a suitable length of steel rod was cut and a 6mm die run down adding a thread at each end; a washer and wing nut would secure the filter in position. Now at last it was all coming together. Next job was to sort out a front door and how to attach it? I settled on a plain sheet of the thick steel sheet and decided to use a stainless steel piano hinge kindly given to me by a friend ages ago for mounting the door. A lot of time was spent in aligning the hinge because I wanted the door to be as air tight as possible. Access to the VFD wouldn't be needed once it was installed because of the remote controls so the door could be screwed closed. I had 20mm cable glands in stock so used the big drill press to bore 18mm diameter holes then opened the holes using a file which was hard work. Short lengths of 1.5" angle iron were cut and drilled then welded into place as mounting brackets ensuring these protruded sufficiently to clear the cowl overhang.
The top cowl at first posed a problem because I wanted to fold the four edges over at 1" deep each? What a pure stroke of luck when my chum David (Yorkie) sent me an email asking if I had use of a metal folder he was about to dispose of; boy did I have use for it and what perfect timing. David very generously gave me not only the metal folder seen below in the picture but also very kindly gave me a lot of very useful kit and a lovely selection of wooden turning blanks ready for when I start using the lathe during winter; thank you so much David. I soon had the metal folder in action; two edges were simple to bend but the other two required the metal to be packed out which wasn't a problem after a bit of thought as to what I wanted to achieve.
The weather was perfect and allowed me to use the big compressor and spray gun. I had a look around and found a tin containing spraying grey primer which was only about 12 years old and being tight I thought this would be ideal so opened the tin and gave the paint a very good stirring using a screwdriver adding thinners. I set everything up and wearing my respirator soon blasted the grey primer on. I was surprised by the vast cloud of fumes this kicked up; it's ages since I used the spray gun and it being an HVLP type I didn't recall it ever causing such a fog? Whoops I had forgotten to adjust the compressor air pressure. it was running in excess of 100psi; WOW I'm not surprised it caused so much fog. When the fog cleared I was appalled as I inspected the newly painted surfaces; it looked like I had applied anti-slip paint as it was absolutely covered in bits; these bits obviously were lumps of paint which had not thinned out. Not to worry though; the paint quickly dried and was flatted with abrasive paper. Next job was to filter the paint then try again which was a success; the few lumps this time were quickly flatted.
I didn't have any paint for the top coat so nothing for it but to get my hand in my pocket and buy some. I didn't want this enclosure to stand out or contrast with the red workshop walls so I took along a paint sample which I had used whilst painting the walls and bought half litre of gloss cellulose getting the guy to match the colour. Once again I set everything up for spraying but what a shock as soon as the top coat was applied; it looked extremely bright to me and I'm colour blind? Not wanting to drive over to Dewsbury again and spend another £11 I'll live with the colour.
At last I now had a heavy metal VFD enclosure which would withstand a nuclear explosion; it's heavy. The door whilst being a good fit would still admit dust so the door and frame were drilled and tapped at 5mm to accept machine screws which would pull the door into close contact. Mounting the enclosure to the wall was easy enough but the new cable glands were too big and needed packing out in order to seal and grip the cables. I had taken careful details of the connections so now all that was needed was to connect up. On Friday morning I got out of bed early intending to get into the workshop but problems with the post office and sending emails took care of the morning. After dinner though I spent a lot of time running the cables and checking and double checking each connection that it was in the right place and tight. Just before tea time I was ready to power up and with great anticipation pressed the start button; the lathe was very ill indeed with its mandrel revolving in jerks and very little control from the speed pot; after concentrating so hard and feeling tired I walked out of the workshop in disgust; I knew if I started in this frame of mind to resolve the problem I would most likely make it a whole lot worse and these VFD's are easily destroyed by playing around with them by a novice?
In bed I was awake thinking about the problem and knowing I had gone to such lengths with all the connections was certain the problem lay elsewhere? I knew the VFD and lathe both worked well together because I had already had them connected but since installing the enclosure I added a remote start/stop button control and also an emergency stop button control but apart from these nothing else had been changed; what a dilemma? I was in the workshop very early yesterday morning; I ignored the computer and I was on a mission being fully charged ready to tackle anything and full of determination. Five minutes later I had a big smile on my face and the lathe was once again running perfectly but this time with a proper start/stop and an emergency stop control added. Thinking about the problem in bed I considered all kinds of weird problems such as the 3 phase and signal cables running in close proximity cross talking? The new controls could also be at fault with possibly a faulty switch contact or even the pot might have been cooked during soldering the connections? The fault however was extremely simple to resolve; even though I had taken so long to ensure everything was correctly connected I still managed to cross a pair a pot connections wiring the end connector to the wiper and the wiper to the end connector; ah well I'm only a novice at this sort of thing but what a huge relief to have the lathe running and now with the new remote controls fully working.
At the lathe I had used an old electric motor "T" box as a small enclosure for the new remote controls; I've had this box since I scrapped a D132 W series Book Motor for the laminations whilst I was installing the three phase so at last it has come in very handy; I cleaned the box up and drilled the relevant holes then sprayed it with undercoat and gloss black using spray cans; I also used these cans to spray the MDF filter support. Labels were printed using the computer and the electrical "danger" logo was found by browsing the web then transferring the logo into "Paint" allowing me to play around with its size before printing off. Sellotape was added to the front of the labels for protection and Bron kindly gave me some double sided self adhesive tape to attach the labels with.
I hope this information is of use because a lot of my time was taken up browsing the web for remote control connections and the enclosure design although looking simple now completed took quite a bit of sorting out in trying to exclude dust but allow clean cooling air to enter.
The Emergency stop control button stops the lathe in three seconds and really isn't needed but it is big enough to hit if something untoward does happen. (Please kindly note this addition Big Al) I believe there is an emergency stop parameter added to the VFD but for my own safety and wishing to retain my good looks I certainly don't want to be near any lathe spinning at 2,000 or 3,000rpm with a screwed heavy chuck installed which stops dead; in such a situation the chuck could remove my head as it breaks free? The start/stop and emergency stop controls are simply wired in series between the VFD DCM and toggle switch centre connections but anyone having problems please just ask and I'll be happy to add the circuit diagram.
With the enclosure in position the paint colour actually blends in quite well; it is still bright but a perfect colour match to the walls; it looks different because the cellulose is gloss so the light hits it differently; I'm happy with it.
Kind regards, Col.
What a busy week I've just enjoyed. I already had a stock of heavy gauge steel sheet so decided to use some of this to make a new metal enclosure for the VFD in order to separate it from dust and debris. This steel sheet was too thick to cut with tin shears and after a couple of cuts had been made on the big Startrite bandsaw the band started to complain as it was shedding teeth. Not wanting to use a hacksaw I resorted to using the angle grinder which is my least favourite power tool but its effective; with ear muffs and gloves worn for protection the grinder produced a big display of red hot sparks.
The sheets were large enough to cut down for each panel but not large enough to bend so an angle iron framework was cut and welded. I used offcuts throughout; the front frame was made from 1" angle the rest from 1.5" angle. Care was taken to align the angle iron during welding and making the frame was a time consuming job. Each panel in turn was fully welded to seal all the joints. I was making it up as I went along; the manual gives minimum air spacing for the VFD so anything larger would be acceptable; I knew I wanted the enclosure to have some kind of air filter to the bottom and at first I considered adding a simple sheet filter but left this alone whilst I gave it more thought. The top of the enclosure would be openly vented but covered by an extended cowl; this cowl would allow the VFD fan to exhaust warm air freely but prevent dust and debris from entering the enclosure. The cowl was made 1/2" larger all around but also would have a 1" deep lip folded so the cowl was cut out an extra 3" longer and 3" wider than the enclosure top in effect I was adding the cowl which would be raised 1/2" using machine screws and nuts for simplicity. I copied the cowl idea from the drip proof cowls which used to be fitted to some motors.
The dimensions I settled with are; 16.5" maximum height; 10.5" wide and 8" deep. The cowl dimensions 11.5" x 9.5" plus an extra inch all around for the folded lip height excluding the filter.
The welding was straightforward but a bit time consuming using my 140A SIP arc welder. With the welds completed the angle grinder fettled the joints. All during this I kept thinking about how to filter the air supply to the VFD and was even thinking about this in bed at night then suddenly it occurred to me to use a car engine air filter? I browsed eBay for a suitable filter and at around £8.50 each they were cheap enough but I thought why not pop into our local auto accessory store? Visiting the store I bought a nice big air filter for under £6 so all I now had to do was to install it. This sounds easy enough but how the heck can I cut a large hole in a thick sheet of steel? After considerable thought I remembered I had recently bought a brand new Erbauer jigsaw which came with a selection of blades including metal cutting blades so I thought I'd give it a try? I drilled a hole in the waste to accept the blade and was amazed just how easy it was to cut the large hole with the saw set at number two on the speed control; a file cleaned the edges of the hole so now I needed means of securing the filter.
Having lathes is a huge asset and I soon turned an 18mm thick MDF air filter base support adding a location rebate; the support was turned at maximum diameter to suit the diameter of the filter and the rebate was turned to suit the inner diameter of the filter thereby locating it in position; a central hole was added at 6mm clearance. A steel square off-cut was cut to length and tapped on centre at 6mm this in turn was tack welded to the inner bottom panel. Next a suitable length of steel rod was cut and a 6mm die run down adding a thread at each end; a washer and wing nut would secure the filter in position. Now at last it was all coming together. Next job was to sort out a front door and how to attach it? I settled on a plain sheet of the thick steel sheet and decided to use a stainless steel piano hinge kindly given to me by a friend ages ago for mounting the door. A lot of time was spent in aligning the hinge because I wanted the door to be as air tight as possible. Access to the VFD wouldn't be needed once it was installed because of the remote controls so the door could be screwed closed. I had 20mm cable glands in stock so used the big drill press to bore 18mm diameter holes then opened the holes using a file which was hard work. Short lengths of 1.5" angle iron were cut and drilled then welded into place as mounting brackets ensuring these protruded sufficiently to clear the cowl overhang.
The top cowl at first posed a problem because I wanted to fold the four edges over at 1" deep each? What a pure stroke of luck when my chum David (Yorkie) sent me an email asking if I had use of a metal folder he was about to dispose of; boy did I have use for it and what perfect timing. David very generously gave me not only the metal folder seen below in the picture but also very kindly gave me a lot of very useful kit and a lovely selection of wooden turning blanks ready for when I start using the lathe during winter; thank you so much David. I soon had the metal folder in action; two edges were simple to bend but the other two required the metal to be packed out which wasn't a problem after a bit of thought as to what I wanted to achieve.
The weather was perfect and allowed me to use the big compressor and spray gun. I had a look around and found a tin containing spraying grey primer which was only about 12 years old and being tight I thought this would be ideal so opened the tin and gave the paint a very good stirring using a screwdriver adding thinners. I set everything up and wearing my respirator soon blasted the grey primer on. I was surprised by the vast cloud of fumes this kicked up; it's ages since I used the spray gun and it being an HVLP type I didn't recall it ever causing such a fog? Whoops I had forgotten to adjust the compressor air pressure. it was running in excess of 100psi; WOW I'm not surprised it caused so much fog. When the fog cleared I was appalled as I inspected the newly painted surfaces; it looked like I had applied anti-slip paint as it was absolutely covered in bits; these bits obviously were lumps of paint which had not thinned out. Not to worry though; the paint quickly dried and was flatted with abrasive paper. Next job was to filter the paint then try again which was a success; the few lumps this time were quickly flatted.
I didn't have any paint for the top coat so nothing for it but to get my hand in my pocket and buy some. I didn't want this enclosure to stand out or contrast with the red workshop walls so I took along a paint sample which I had used whilst painting the walls and bought half litre of gloss cellulose getting the guy to match the colour. Once again I set everything up for spraying but what a shock as soon as the top coat was applied; it looked extremely bright to me and I'm colour blind? Not wanting to drive over to Dewsbury again and spend another £11 I'll live with the colour.
At last I now had a heavy metal VFD enclosure which would withstand a nuclear explosion; it's heavy. The door whilst being a good fit would still admit dust so the door and frame were drilled and tapped at 5mm to accept machine screws which would pull the door into close contact. Mounting the enclosure to the wall was easy enough but the new cable glands were too big and needed packing out in order to seal and grip the cables. I had taken careful details of the connections so now all that was needed was to connect up. On Friday morning I got out of bed early intending to get into the workshop but problems with the post office and sending emails took care of the morning. After dinner though I spent a lot of time running the cables and checking and double checking each connection that it was in the right place and tight. Just before tea time I was ready to power up and with great anticipation pressed the start button; the lathe was very ill indeed with its mandrel revolving in jerks and very little control from the speed pot; after concentrating so hard and feeling tired I walked out of the workshop in disgust; I knew if I started in this frame of mind to resolve the problem I would most likely make it a whole lot worse and these VFD's are easily destroyed by playing around with them by a novice?
In bed I was awake thinking about the problem and knowing I had gone to such lengths with all the connections was certain the problem lay elsewhere? I knew the VFD and lathe both worked well together because I had already had them connected but since installing the enclosure I added a remote start/stop button control and also an emergency stop button control but apart from these nothing else had been changed; what a dilemma? I was in the workshop very early yesterday morning; I ignored the computer and I was on a mission being fully charged ready to tackle anything and full of determination. Five minutes later I had a big smile on my face and the lathe was once again running perfectly but this time with a proper start/stop and an emergency stop control added. Thinking about the problem in bed I considered all kinds of weird problems such as the 3 phase and signal cables running in close proximity cross talking? The new controls could also be at fault with possibly a faulty switch contact or even the pot might have been cooked during soldering the connections? The fault however was extremely simple to resolve; even though I had taken so long to ensure everything was correctly connected I still managed to cross a pair a pot connections wiring the end connector to the wiper and the wiper to the end connector; ah well I'm only a novice at this sort of thing but what a huge relief to have the lathe running and now with the new remote controls fully working.
At the lathe I had used an old electric motor "T" box as a small enclosure for the new remote controls; I've had this box since I scrapped a D132 W series Book Motor for the laminations whilst I was installing the three phase so at last it has come in very handy; I cleaned the box up and drilled the relevant holes then sprayed it with undercoat and gloss black using spray cans; I also used these cans to spray the MDF filter support. Labels were printed using the computer and the electrical "danger" logo was found by browsing the web then transferring the logo into "Paint" allowing me to play around with its size before printing off. Sellotape was added to the front of the labels for protection and Bron kindly gave me some double sided self adhesive tape to attach the labels with.
I hope this information is of use because a lot of my time was taken up browsing the web for remote control connections and the enclosure design although looking simple now completed took quite a bit of sorting out in trying to exclude dust but allow clean cooling air to enter.
The Emergency stop control button stops the lathe in three seconds and really isn't needed but it is big enough to hit if something untoward does happen. (Please kindly note this addition Big Al) I believe there is an emergency stop parameter added to the VFD but for my own safety and wishing to retain my good looks I certainly don't want to be near any lathe spinning at 2,000 or 3,000rpm with a screwed heavy chuck installed which stops dead; in such a situation the chuck could remove my head as it breaks free? The start/stop and emergency stop controls are simply wired in series between the VFD DCM and toggle switch centre connections but anyone having problems please just ask and I'll be happy to add the circuit diagram.
With the enclosure in position the paint colour actually blends in quite well; it is still bright but a perfect colour match to the walls; it looks different because the cellulose is gloss so the light hits it differently; I'm happy with it.
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
