By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for Les Jones 1

Here is a list of all the postings Les Jones 1 has made in our forums. Click on a thread name to jump to the thread.

<< First < Prev 104 105 106 107 108 109 110 111 112 113 114 Next > Last >>
Thread: Chester Mini Mill - X2?
19/07/2010 12:44:55
Hi Deril,
                 I think a 12 - 0 - 12 V transformer will probably be correct. With a capacitor input filter (Which is what the circuit  is.) the DC output will be near the peak voltage of the sinewave which will be 1.414 x 12 = 16.97 The actual value will be a little less than this due to the voltage drop across the diodes and winding resistance. I think you are correct that the 7 and 9 are transposed.
Les.
18/07/2010 15:14:53
Hi John,
               Here is a web page with some information as to which boards have been used in which machines.
 
Also I have traced the schematic for the board in the X3 mill. Let me knoe if you would like a copy of the schematic.
Les.
18/07/2010 12:47:14
Hi all,
           Here is a link I found with some information on the X2 controller board.
 
I think I have seen somewhere that there are several versions ov this board so Deril will need to check that this information is reffering to the version he has. Also he does not say what the fault is with the transformer. (ie open circuit primary or secondry etc) I think he should be sure the transformer is faulty before trying to fit a replacement.
Les.
Thread: Demagnetiser
25/06/2010 09:24:04
Hi Terry,
                 I just did a search for the word "demagnetise" and found the thread you are looking for. (How do I demagnetise tools and parts of machines)
In the past I have also had problems finding old threads.
Les.
Thread: Low rev. dynamo
10/06/2010 20:28:27
Hi Johan,
                   You could try to find a magnet that could be placed between the pole pieces of rotor of the car alternator. This would remove the need for it to generate the power to magnetize the rotor. Possibly a magnet from a loudspeaker would do if you can find one of the correct dimensions.  I have not tried this myself but it may work.
Les.
Thread: Propane Cylinder Size - Choosing
22/05/2010 18:08:25
Hi Steve,
                  To get more than the maximum output of one cylinder you need to connect a number of cylinders to a manifold. Even if you can get the 43 KW output from a 3.9 kg cylinder (Possibly by putting it in a tank of warm water.) then it will not last very long. look on the web to convert 43 KW to KG per hour of propane. It would not be very good to run out of gas part way through the work on your boiler.
Les.
21/05/2010 20:15:48
Hi Steve,
                 The title of the thread I mentioned in my last reply  is "Boiler making hearth"
Les.
21/05/2010 19:05:41
Hi Steve,
                  I wave just done a search on the web for maximum take off rates. I found that a 13 kg propane cylinder has a maximum recommended take of rate of 15  KW Even a 47 KG cylinder is only recommended for 34 KW I have used a 3.9 KG cylinder with a blow torch for many years but I think the largest burner would be about 10 KW. You could try to find a 6 kg cylinder on Ebay to save on the deposit.. It might be worth considering using insulating fire brick or ceramic fibre blanket  to insulate the boiler rather than use 43 KW of heat. There has been on ongoing topic on silver soldering boilers but I can not remember the thread title. There is some useful information there if you can find it.
Les.
Thread: Hobbymat MD65 needs assistance to start
20/05/2010 08:54:51
Hi Clive,
                I am assuming the motor is a fixed speed induction motor. Based on this assumption I suspect the contacts on the reversing switch which connect the start winding in the forward direction are faulty. I cannot find a wiring diagram on the web to tell you which connections on the switch to check. If you have the manual I think that contains the wiring diagram. If so then if you scan it in and attach it to your next post I will be able to tell you which contacts to check.
Les.
Thread: Back to the Workshop
17/05/2010 22:42:47
Hi William,
                       I think the jet you are using is too large or the total cross section area of the holes in the ceramic grill part is too small. I found a web site with information on the burner design you are using and it suggests a number 8 jet. I then tried to fined what the hole size is in a no. 8 jet. I found this website  Gas jets  It suggests that a no. 8 jet is 0.25 mm diameter. you do not say what size jets you have tried so if your jet is this size or smaller I do not know what to suggest.
Les.
Thread: Anodising
15/05/2010 20:49:19
Hi Ramon,
                    I seem to remember in the distant past reading that to get the anodising thick the voltage had to be increased during the process. This is because the anodising is a partial insulator so as it builds up the voltage required needs to be increased to keep the current constant. You should be able to verify this by watching the current as the anodising progresses. If it decreases (With the voltage constant.) then my memory is correct. If it does not decrease I must be talking rubbish.
Les. 
Thread: Automate Paper Guillotine Back Fence
03/05/2010 22:42:14
Hi Peter,
                 After making the suggestion about the "DivisionMaster" I had a look at the web site of the designer. I found that the source code was not available so it could not easily be adapted. To use it you would have to write the code from scratch. I did not realise the ELS was so versatile. All of the hardware you require is in both devices. The advantage the ELS has is that the source code is available so you could modify it to do exactly what you want. I cannot offer any help to modify the ELS code as it is written in "C" and I have not yet learned to program PIC's in "C" (I work in assembler.)
Les.
03/05/2010 18:38:14
Hi Peter,
                 I do not think the electronic leadscrew would serve your requirements. I works like an electronic gearbox. It senses one pulse per revolution from the headstock spindle and generates a string of pulses to drive the stepper motor at speed which is a set ratio to the spindle speed. For example if the leadscrew  has 10 threads per inch and you want to cut a 26 TPI thread then the lesdcrew needs to be rotated 10 times for every 26 revolutions of the spindle. So if the stepper was coupled directly to the leadscrew  and the stepper requires 200 steps per revolution (Which is a fairly common value.) 2000 step pulses would be required for every 26 revolutions of the spindle. It also needs to be kept in phase so that the thread is cut accurately. I imagine that you want to be able to key in the required distance between the blade and the fence and the stepper motor to move the fence to the required position. This could be done with a PC or a microcontroller. If this is what you require each time the equipment was switched on it would have to set its zero position using a sensor or driving to a mechanical stop. The "DivisionMaster" rotary table controller could probably be adapted for your purpose. Here is a link to some information on the DivisionMaster. DivisionMaster
Les.
Thread: Stepper Motor General/Basic Question
25/04/2010 19:36:46
Hi Peter,
                 As Martin says a lot depends on your exact requirement. For example the torque requirement and how critical missing a pulse would be. The inertia of the system would also influence the design. Your requirement does not rule out using a DC motor but it would require using a position encoder. There is a design called the "UHU servo" that may fit your requirements.  Here is a link to it.  UHU Servo
Les.
25/04/2010 09:40:22
Hi Peter,
                  I do not think there is a simple answer to your question. A lot depends on the design of the driver electronics. As you run a stepper motor faster the inductance of the windings has more effect which means that a higher supply voltage is required. This then means that a way is required to limit the current at lower speed or when the motor is stopped. This can be just series resistance but this is very inefficient. Pulse width modulation is normally used to control the current. From what I have read it is normally recommended to buy the stepper motor drivers rather than design your own. Here is a link to some good information on stepper motors.
Les.
 
Thread: Can Anyone Name this Engine?
20/04/2010 09:38:05

Hi Neil,
               Here is the picture of the Suffolk Colt engine.
 

 
 If you would like a higher resolution picture send me a message on this forums mail system with a normal email address so I can attach the photo.
Les
19/04/2010 22:56:27
Hi Neil,
                 I think the engine may be from a "Suffolk Colt" lawnmower. Next time I have a look in the garden shed I will have a closer look to see if it is the same as the engine on my lawnmower. I have just had a look at the manual and it looks very similar. I will scan the picture of  the engine in the morning and put it on another reply.
Les. 
Thread: Re-wiring a forward/reverse switch
08/04/2010 08:53:26
Hi John,
                 I agree with David (Engine builder.) The two pairs of wires from the motor will be the start and run windings. The start winding will probably have a capacitor connected in series with it. (At motor end.)  Label the four wires from the motor with the switch terminal number / letter. (As you have two blacks and two reds) Disconnect these from the switch to avoid paths through the switch causing confusion. You will either find two pairs showing continuity of a few ohms or one pair showing continuity and the other pair open circuit  (Or a vary high value of a few hundred K ohms if there is a safety discharge resistor  across the start capacitor.) I you are using an analogue meter it will flick when first connected as the capacitor charges.  If you do get one of these results then connect one pair to their original terminals and connect the other pair to the original terminals but swapped over.
If you cannot identify the two pairs for any reason then DO NOT SWAP ANY WIRES OVER but reply with the results for further thoughts or suggestions.
Les.
 
Thread: Anodising
30/03/2010 09:47:56
In the process of aluminium dissolving caustic soda (Sodium hydroxide) hydrogen is given off which would be a fire / explosion risk. I would think a brief dip in the caustic soda would be OK.
Les.
Thread: Brazing torch
24/03/2010 08:42:27
Hi Bill,
            If you choose the "Sievert" torch option I bought mine from Millhill Supplies
Millhill Supplies   But have since found that  that "Hamilton Gas Products" are cheaper
Hamilton Gas Products   I went for the 3486 handle and the 3525 cyclone burner. (10.2 KW)  I found there is a large variation in prices from different suppliers.
Les.
<< First < Prev 104 105 106 107 108 109 110 111 112 113 114 Next > Last >>
Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Shopping Partners
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate