Here is a list of all the postings Absolute Beginner has made in our forums. Click on a thread name to jump to the thread.
|Thread: Convertor Issues 240V 1 phase to 415V Three Phase|
Well I thank you all for your advise. I will aim to continue to use the device in "Plug and Play Mode" a scenario that many are obviously unfamiliar with, and will install a so called daft soft starter, and will let those who might be interested know how I get on. It just might come in helpful to others in the future.
Sorry to those that think I must use the functions of the VFD, its just not an option that I wish to pursue
I will make it clear whilst I have asked for opinions and advise, unfortunately the advise given by some is pointless as they hacve mis understood the question being asked, sorry but fact.
However I will say as always its interesting to sift through some of peoples thoughts, opinions and advise as on occasion a real jem appears.
Again thank-you. Now where do I find the so called daft soft starter?
Sorry I don't understand what you mean. The soft start would be inserted between the contractors output and the motor.
As for the independent supply to the cofactors and control switchgear, that is via 240V single phase into a transformer on the machine which provides 110v supply to the contractor coils
Many thanks for your replies.
For those few that understand my dilemma many thanks. Jon, again many thanks for your comments however I would stress the following.
Currently the Convertor starts the lathe, in any gear, and with no assistance every time. my only thoughts are that it probably dosent like it due to the high inrush current and that it will be counting down the time to failure.
I cannot see why a soft start won't work hence my question. Unfortunately no one has provided me with a reasonable explanation as to why the soft start won't work. Jon your explanation about the chattering of the contractors is not relevant in my case as I have supplied the control circuitry with an independent supply. Hence the soft start has no effect on the contactor coil voltage that pulls the contractors.
Therefore my question comes down to ......I assume with 415V ramped up slowly to the motor supplied by a soft start device the inrush current should be limited and hence the load on the convertor reduced and its life elongated? and save me £2000 for the price of a new device!
So whilst I am awaiting contact from JBCuttingtools. I thought I would ask for views on my latest update of my underpowered convertor situation.
Having established, and understood by some, that the convertor changes 240V single phase to 415V three phase in plug and play mode and that the convertor (5HP) is underpowered for my lathe Colchester Student 2500 2.2KW + 3HP on start up.
It was suggested to me that I insert a soft starter between the Converter and motor supply.
So I cant see why the convertor would not be able to power the motor as the soft starter would limit the inrush current on start up, and take the strain away from the convertor
Anybody have any constructive thoughts???
I Cant see why it wouldn't be an OK solution!!!
|Thread: JB cutting tools .com|
So does anyone have a phone number for them as nothing listed on Website. As they they were ordered on the 11th October its been 7 days without any news!!!
I wonder if anyone else has had dealings with JB Cutting tools.com
They seem to suggest that they supply British made Lathe cutting tools.
Have placed an order, they have taken my money,,,,No goods received and no reply to emails sent.
Staring to get a little concerned. Order placed 11th Oct no contact or goods since!
|Thread: Sustainability of under powered VFD on Initial motor starting|
Thank you all for your comments. Bill has hit the nail on the head and replied accordingly and for that I am most grateful. Yes my device indeed is connected to a suitably rated circuit. One of the benefits of plug and play mode is as Bill has correctly pointed out... the ability to run more than one single voltage motor per machine, i.e. lathe drive + suds pump + Low voltage transformer for Men type light, + workshop ring main and in addition also allows me to take off a 240v volt supply for my newly installed DRO.
In addition because it has EMC filtering, and a sine wave filter installed it is capable of driving all the inbuilt contractors and any other electronics as required.
unfortunately the drive you link to is only 230v, not 415v and is incapable of running all the control switchgear. Hence the need for a higher cost plug and play device in this instance that coverts single phase 230V to 3 phase 415V and has inbuilt EMC filtering and sine wave filtering to produce a cleaner PWM sine wave capable of operating contractors and relays etc so that the lathe can be controlled from its intended original controls.
Because of this as per my original post the 5HP unit, I am guessing is put under considerable strain starting the 3HP motor....
In plug and play mode the VFD just supplies a nominal 415V at 50Hz, so unfortunately some of the benefits usually associated with VFD's is lost. The device I have is rated at 5HP, although it can cope with a 50% overload for 30 secs or so. My Colchester Lathe has a 2.2KW motor approx 3HP which when switched on utilising the VFD in a plug and play mode will need many times this, so the soft start protection is not applicable...at least I think this is the case...hence the strain of the VFD?
Now why didn't I think of that, thats a link in the right direction, again. Thanks
I have a 5HP Drives Direct VFD which I currently use in a plug and play mode to power my Bridgeport Mill. No problems at all. I have recently purchased a "new to me" Colchester lathe a Student 2500 and have wired my VFD in a ring main configuration to provide power for it, No they will not be run together. Yes my lathe now seems to run ok but the convertor is somewhat underpowered at 5HP to cope with the initial start up inrush current on the Colchester lathe at 2.2KW.
I just wondered if anyone else had ever done the same, and if my VFD will continue to cope with the initial inrush current requirements of the lathe? The option to purchase another VFD is an option but having initially spent around £1400 on the original 5HP device I want to try and get some use out of it. Yes I can purchase another VFD but understand I will need a 10HP device at around £2400...eek
So maybe I will have to if the 5HP fails, hope it lasts a bit??? Just wondered if anyone else had any experience in doing the same or else any alternatives as to a cheaper solution?
|Thread: How much do Colchester spares cost ?|
I purchased some spares for my "New to Me" Colchester Student 2500 Lathe Manufactured Yr 2007 today.
I have listed these prices for general info
They were always rumoured to be expensive but these prices take the biscuit.
|Thread: Indexable Lathe tooling|
Many thanks for taking the time to post a detailed succinct reply. Much appreciated.
Many thanks for the Link, looks to be some great info here. I will study with great interest. Again. Thank you.
Just a couple of questions. Having only turned my, new to me lathe, on for all of 5 mins and having finally worked out what the knobs and levers do I started to look at lathe tooling feeling very happy!. That was until I got completely lost with tooling holder types and Insert variants. I have a Dickson QCTP fitted to the lathe nd can accommodate 20mm tooling.
So I just wondered if a few of you helpful chaps might be able to point me in the correct direction. I have decided to plump for indexable rabid Tooling and holders and have come across the Cutwell site on the internet which hols a host of variants and information.
I have researched and now am starting to understand the ISO labelling and part numbers ref holders and Inserts.
What I need help with is which variants should I purchase, ie 95 degree, 75 degree R hand Left Hand..or do I just purchase a starter set fro Chronos or the like. I think I understand parting tools to get me going.
In particular could anybody assist me with which angle should I leave the Compound table/slide when using the holders and inserts. I presume at 90 Degrees to the saddle is OK??? Do really need to move to 30 degrees for thread cutting with thread specific inserts?
Finally, do I understand that the cutter inserts are specific to the threads that are being cut, and I will need a different insert for each pitch...seems a lot of inserts will be needed?
I have been googling and have ordered a few books for more Lathe tooling/ operating reading when they arrive, but had just hoped that someone might be able to assist me to get me going with ordering some tooling.
Many thanks in anticipation
|Thread: Confused abut the oil?|
I am sorry to ask such a basic question but I have finally taken delivery of my first Lathe, A colchester Student 2500 Year 2007.
Unfortunately, I cant seem to get my head around the correct oil to use. The user manual suggests DTE Extra Heavy amongst others but the lubrication diagram points towards the headstock, but it is unclear, as the diagram also seems to indicate A Energy HLP 37 toward the same place, which I assume is the two oil filler spouts when the headstock cover is removed.
Is there anyone who might be able to point me in the correct direction please?
|Thread: Aluminium thread strength|
Well again you are right on target. One of my other hobbies is Ham Radio. For years I have made various antenna towers and mast like you have described. There was once a company here in the uk who manufactured steel telescopic towers. They were based upon triangular lattice sections 6 meters long, of differing dimensions. 16 Inch, 13 Inch and 10 Inch, with some even including a 7 inch section. Raising to approx 75ft. They slid and telescoped within one another. I have made countless copies of these type towers over the years. They will on "Limit" hold a HF yagi with rotator and having a wind area of some 2 square meters and weighing up to 150KG unguided up to 50MPH. I have done so. They are no longer manufactured. There are still loads about "Versatower" is the name of choice, however they are getting old now and also expensive.
The one disadvantage of these towers is the weight. Made of steel they weigh close to 1000kg with the ground post typically another 150KG and needing 2cubic meters of concrete foundation, minimum.
I am looking into fabricating a similar type tower but out of Aluminium. They are made in the States, but not here in the UK. I haven't played around with aluminium much and an a steep learning curve. 6082T-6 seems to be the off the shelf, readily available structural stuff in various tube wall thicknesses.
Hence my somewhat stupidly sounding questions. I am considering and looking into bolting the aluminium tube sections together, with horizontal and diagonal struts, as welding Aluminium is a real art, and welds that cosmetically look good are typically not structurally sound.
Still playing around with ideas, and welcome comments from the forum which has such a wealth of information and knowledgable people, such as yourself.
Many thanks for your thoughts and suggestions, I am going to try a few ideas and see how they look, feel and stand up to some of my testing.
What as super drawing. If only I could do that. I can only just about manage a few lines on Autocad.
Your drawing is spot on. Spot on. If you imagine a mirror image of the tube and plate approx 500mm apart and a piece of aluminium tube 30mm diameter connecting from plate to plate you have the whole picture. Its a truss like structure and the plates are at approx 500mm intervals along the length of the 5 meter tube and the aluminium tube links are both horizontal and at 45 degrees like you would see on an aerial mast. As essentially that is what I am trying to make.
Well, I didn't expect quite that number of replies. So again many thanks for all answers. All read and greatly appreciated. Perhaps in some areas my description was lacking somewhat as its always difficult when describing things on forums. To try and put some minds at rest, for those still wondering, I will try and provide a more exact explanation for completeness.
I have a 2 inch diameter 5 meter long Aluminium tube approx 1/4 inch thick - think of Aluminium scaffolding pole
I need to fasten a piece of aluminium bar to its surface, i.e two the surface of the 2 inch diameter on the 5 meter length. The aluminium bar measures 150mm Long x 40mm high x 8mm wide/thick
I was referring to bolting through the 2 inch tube into the bar, the interface with the bar is onto the 8mm face of the aluminium bar, so as a few people have pointed out not much meat left in 8 mm thick Aluminium bar after either tapping through or making clearance holes and a nut to secure it via the 8mm face/thickness. Though there is some 40mm height of material. Hence the need perhaps to go to 10mm thickness, or reduce the bolt diameter.or both smaller bolt and 10mm material. Unfortunately, I am unable due to other restraints, to increase the bar thickness above 10mm.
I hope that clears up any discrepancies. From the kind answers provided I think I will try and tap the aluminium bar with two M5 threads, one close to each end of the ends 135mm apart in the 150mm length to accept stainless bolts with about 18 - 20mm thread engagement in 10mm thick aluminium. All the aluminium is 6082-T6.
I hope that will be job done. The bar provides an interface bracket for another aluminium tube 30mm diameter, which forms a horizontal joint in a horizontal Truss Beam. ( I know thats as clear as mud now!) Will give it a go and see what happens under some crude testing. Its not a critical truss beam, so no life threatening disaster should it fail.
Many thanks, and again very much appreciate all the replies
What a fanatic concise reply. Thank you. The material is 6082T-6 not anticipated to have to remove the thread once assembled. I had no appreciation that 2 D insert length + approx 8.8 bolt strength. I wish all structural engineers could produce such readable and understandable answers. Again many, many thanks.
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