Thanks: 0
Likes: 0
Picture(s) thanks: 0
Results 16 to 30 of 50
-
11th Jul 2012, 03:11 PM #16Most Valued Member
- Join Date
- Jul 2010
- Location
- Melbourne
- Posts
- 9,088
-
11th Jul 2012, 05:10 PM #17Senior Member
- Join Date
- Jun 2008
- Location
- Newport, Victoria
- Posts
- 117
Stuart,
Hopefully not the last question, questions are what make the threads interesting )
Agree nothing wrong with a little over engineering. I would have gone for the three leg setup like your stand but i'll get around to putting some drawers in the stand to make use of the space. I also made the stand so that the surface plate will overhang by 5mm on all sides. I thought it may come in handy if I ever have to scrape or measure the inside faces of something "L" shaped.
Below is a diagram of the cutting path.
Attachment 215293
It was two passes the last one was a finish pass at 0.1mm. 19.5mm DIA cutter, Initial pass: 775 RPM, feed rate 243mm/min.
Christian
-
11th Jul 2012, 11:48 PM #18Senior Member
- Join Date
- Dec 2011
- Location
- South East Queensland, Australia
- Posts
- 355
Hi CGroves, All looking good, coming along nicely.
Regarding a gasket at the duplex bearing end, if it's the set up I think it is then it's probable that there was no gasket on that end. If you put a gasket in you may not be allowing the spigot on the end plate to push the outer races of the bearings together thus effecting the correct preload and also holding hold them tight in the housing. Usually there is actually a small air gap between the housing end and the flange of the end cap thus ensuring that the bearings are being clamped by the spigot, one can use a soft compressible gasket "goo" or some such to take up the air gap.
Cheers.If I'm not right, then I'm wrong, I'll just go bend some more bananas.
-
12th Jul 2012, 11:30 PM #19Senior Member
- Join Date
- Jun 2008
- Location
- Newport, Victoria
- Posts
- 117
The motor is the last piece of the surface grinder to be disassembled. I
The motor plate says:
Mc Coll Electric Works Ltd.
Refer No. 35409 XD316
F.R. 3524 Type 0ZX31
RPM 2850 0.5 HP 3PH 400V
Here's a couple of pictures of it in pieces, not exactly pristine.
Attachment 215451 Attachment 215452
It looks like the fan side bearing has been replaced at some stage. As it has a metal side and other side open (the pulley end is completely open). The fan bearing is also a newer bearing. The pulley side bearing is not real good. I can only assume whoever previous changed the bearing couldn't remove the pulley to get to the bearing on that side. The bearings are numbered 6202.
Here's the connection block. I assume from the connectors that I won't be getting away with getting it reconfigured to 240volts
Attachment 215453
As I mentioned the surface grinder is now completely disassembled. Most of the components have been degreased and cleaned up. Now to see about getting the paint removed so that I can respray it. My current plan is it to get it sand blasted off, although I'm yet to investigate that.
Christian
-
13th Jul 2012, 12:03 AM #20
OK, Christian, that motor won't be much of a problem. And if it is, I will happily give a 1/2hp 3-phase replacement motor (I have several, but can't recall if any of them are 2800rpm.
Firstly, you will need to thoroughly clean the coils and wiring. Do NOT use any solvents. Used compressed air in the first place, using paint brushes to move most of the dust and crud. There are special motor cleaner liquids but I haven't seen any for a while. I would try 'oil and wax remover' that spray painters use. I don't believe it's a solvent - others here may know better. A cheap degreaser may be OK too.
The 6202 bearings are cheap off the shelf bearings - you can afford to buy brand name ones and don't use a hammer to mount them on the shaft - press them on. Same with the motor end shields when you reassemble: don't hit anything with a hammer.
Incidentally, the play you felt in the spindle bearings: they are angular bearing which are ALWAYS 'loose' until they are fitted in pairs and loaded in the direction of their angular contact. When you mentioned that they had some play, was that on the spindle, still installed or seperately in your hand?
The reconfiguration of your motor for 240V is fine. I'll post a photo shortly with some explanations for you. It is currently wired in 'star' shape and needs to be wired in 'delta' shape. So there is a 'star point' connecting the three sets of windings together - the other ends of the coils which are not connected to the terminal block.
Whoever changes this - maybe you - brings three new wires out into the terminal box - probably through the same holes of the current wires - and connects them to the three wires in the box into the same terminals.
Joe
-
13th Jul 2012, 12:52 AM #21
Here is a picture of your motor stator with an indication of what's going on.
The following is a description of what a motor rewinder will do - and I have done several times. It is NOT an instruction to anyone not familiar with the hazards of electric motor windings.
If anyone attempts this on their own motors, they take full responsibility for their own actions! The work itself is not dangerous, but if mistakes are made, the insulation could deteriorate or be damaged and make the motor and/or the machine it is attached to fatally dangerous once in use - even much later on!
After everything is cleaned, one will have to look very closely at the spagetti tubes I indicated in white and see how many wires go into them at each end. It looks to me that one or two of them near the top of the picture have wires going in at just one end - an idication of a likely junction point.
When one finds the one that has 3 wires going in - possibly two from one end and one from the other - very gently slice open the spagetti tubing. Once the wires inside are visible, and it can be confirmed that there are 3 wires twisted and soldered together, they can then be freed completely - maybe by trimming off some of the string bindings - without scratching the lacquer of any adjacent wires. These three wires are then lifted clear of the coil and either unsoldered while untwisting, or - if enough wire can be freed of each - the twisted bit can be cut off.
Next one needs to solder 3 new flexible insulated wires (preferably nice soft silicone insulated flex) onto the now separate and free ends. These flexible wires only need to be around 1mm2 or less cross section - quite thin - because each doesn't carry much current all in a 1/2hp motor.
The next step is routing these three wires - safe from possible contact with the spinning rotor, once reassembled - back to the terminal block.
Slide some new spagetti tubing over these joints to insulate them, bend the coil wired back tight to the coils and fix them there with epoxy adhesive - e.g. 5 minute Araldite or better. Since epoxy doesn't actually stick to silicone and some other insulation, it needs to encapsulate the whole wire to hild it in place one cured. Epoxy is also a good insulator for the soldered joints, the spagetti tubing covering it can be sealed with it at both ends.
Each of the new wires needs to be identified to be the 'mate' to one of the original wires in the terminal box with a multimeter.
The new wire connected to the coil wired to terminal 1 should be pulled through the hole adjacent to teminal 2, the new wire 'mate' of terminal 2 is pulled through to terminal 3 and that mating with terminal 3 pulled through the whole next to terminal 1.
By then connecting the 3 new wires to their nearest terminals, the delta configuration is completed.
At every construction step along the way, a check should be done to confirm that NONE of the coils have any continuity with each other or the motor frame. There should be NO continuity between any coils until the final connections in the terminal block are made - when all three coils are connected to each other.
Hope that explains the process and allows members to ask intelligent questions off a rewinder - or the knowledgable adventurers amongst us to do it ourselves.
Joe
-
13th Jul 2012, 09:04 PM #22Senior Member
- Join Date
- Jun 2008
- Location
- Newport, Victoria
- Posts
- 117
Hello Log,
I was having trouble getting my head around exactly how the spindle head is put together. So I decided to measure it. Below is a section view of the spindle head assembly:
Attachment 215547
It seems you're right about the air gap. Based on the measurements once its all assembled there will be an air gap ~1.3mm. The end caps are slightly different the wheel end cap loading the bearing outer rim and the pulley end cap loading the bearing in ring.
I still don't understand why the end caps have a curved groove on them (indicated by the ???). I also don't understand how the oil is going to stay in the spindle head. Its not exactly a tight fight between the end caps and the spigot and the bearings aren't sealed.
Thanks, Christian
-
13th Jul 2012, 09:40 PM #23Pink 10EE owner
- Join Date
- Aug 2008
- Location
- near Rockhampton
- Posts
- 6,218
I wonder if your grinder is supposed to have an oil drip feeder on top where you currently have an oil cup, like in this picture from a 1949 catalogue.. it would be a total loss oil system design.... Also those bearings are not thrust bearings, they are angular contact bearings.. Also the bearing on the other end is a precision bearing as well, I think I can see the high spot mark on the outer race in the picture... It looks like an arrow, the same mark is on the two angular contact bearings.. Fafnir number for a 6205 precision bearing is MM205, if you wish to search for one..... My Macson Tool and cutter grinder has the similar spindle bearings in it as your surface grinder uses (they are a bit bigger).... I got precision bearings from US ebay for it... They were not cheap, but a lot lot cheaper then I expect they would have cost here...
Gold, the colour of choice for the discerning person.
-
13th Jul 2012, 09:48 PM #24Senior Member
- Join Date
- Jun 2008
- Location
- Newport, Victoria
- Posts
- 117
Hello Joe,
Thanks for the detailed information on the motor. Glad to know there's a possibility, although its not as simple as changing the bridges between the leads. Given the possibility of stuffing up the coils and that its not exactly an item that easily replaced with like I think i'll be taking it to a motor rewinder.
With respect to movement in the thrust bearings I don't know to quantify the movement but a new bearing whilst having some play in still feels "tight" the existing bearings felt really loose. Even when on the spindle with the spigot installed there was some play.
I don't believe in cheapo bearings so i'll be putting in decent ones and will be avoiding the use of a hammer. When I was at high school I used to work at a place recycling plastics pulling apart shrink wrap bales to feed onto a conveyor belt. One of the fitters would take pity on me and take me to help him. One day he asked me to remove a motor flange and left me to my own devices... my tool of choice a "hammer". Didn't know what a gear puller was. Needless to say the reaction of the fitter to "hammer finished" flange has meant to this day the hammer sits safely in the tool box for these sorts of operations
Christian
-
13th Jul 2012, 10:08 PM #25Senior Member
- Join Date
- Dec 2011
- Location
- South East Queensland, Australia
- Posts
- 355
Hi, Regarding the wear marking on the pulley end end cap as shown in earlier pics this is probably because the "spigot", as you have called it has been loose at some stage and allowed the bearing inner ring to rub against that section of the end cap. You won't need to remove that damage just dress off any burrs. The bearing is clamped on the shaft by the spigot(as you said) and as the shaft expands lengthwise the outer race of the bearing can slide in the housing.
Regarding oil; from your earliest pics it appears(?) that the oil sight glass level line is lower than centre line of the shaft, the line is maybe/possibly in alignment with the lowest periphery of the shaft, if this is so then you should not lose oil when the spindle is stationary and during running you will lose oil slowly. As pointed out by .RC. there was originally an oil drip feeder, maybe that is what was on yours before the flip lid oiler that is now on yours(as per earlier pics).
Cheers.If I'm not right, then I'm wrong, I'll just go bend some more bananas.
-
13th Jul 2012, 10:11 PM #26Pink 10EE owner
- Join Date
- Aug 2008
- Location
- near Rockhampton
- Posts
- 6,218
-
13th Jul 2012, 10:20 PM #27Senior Member
- Join Date
- Dec 2011
- Location
- South East Queensland, Australia
- Posts
- 355
If I'm not right, then I'm wrong, I'll just go bend some more bananas.
-
13th Jul 2012, 10:35 PM #28Senior Member
- Join Date
- Jun 2008
- Location
- Newport, Victoria
- Posts
- 117
Hello Rc,
Sorry about the terminology... the bearings have "thrust" on them so that's what I was using.
I've got a 1955 catalogue and it doesn't show the oil drip feeder. I've got pictures of other Macson bench surface grinders that show the same oil cup that I have. The spindle housing also has a sight glass in it.
Although I think I know how the oil stays in, geometry. Oil level lines in the sight glass are fairly narrowly space. Measuring the height of the lines, the top line corresponds to exactly the same height as the inner diameter of the end caps.... So maybe this circular groove is catching oil thrown to the top when the spindle is turning and returning it to the bottom? If one looks closely the groove isn't entirely circular there's an angle on the outside of it. So the top half would collect oil and the bottom part would allow the oil to flow out. Clever designer....
ChristianLast edited by CGroves; 13th Jul 2012 at 10:38 PM. Reason: oil drip feeder not oil cup.
-
28th Jul 2012, 08:33 PM #29Member
- Join Date
- Mar 2012
- Location
- adelaide
- Posts
- 91
I liked the look of your grinder so much i went out and got one, well sort of
i have a 3A Hercus tool and cutter grinder i got a while ago, surface grinding was what i was after and it seemed a bonus that i could allso do cylindrical grinding etc it came with a magnetic chuck but sadly the vertical feed is way to course to do a good job as a surface grinder
So when the macson showed up i grabed it, but allas its missing the counter balance springs and mech, could you include some pics and some dimension so i can chase up some springs and sort it out, i gather the springs are anchored in the base with the cross pin (missing on mine) dont know if the pully is there will try to see during the week, whats at the top of the springs ? had any luck with a manual ? what are you going to use for spindle oil ? Vactra 2 for the ways ?
yep another machine, might sell the Hercus see how i go
Cheers
Fred
-
30th Jul 2012, 03:12 PM #30Senior Member
- Join Date
- Jun 2008
- Location
- Newport, Victoria
- Posts
- 117
Hello Fred,
Any chance of you posting a photo of the grinder? It would be good to see how it compares to the one I have. I now know of 10 grinders. There seems to be a couple of design variations.
Unfortunately I haven't been able to find a manual. I've contacted the Melbourne model engineers society and found another owner but no manual. I've managed also to track down two Macson ex-employees. One is still checking with his contacts, fingers crossed he comes up with something.
In terms of oil, the for slideways I'm intending on using a Vactra 2 or equivalent. For the spindle I haven't worked that out yet. I'm open to suggestions on this one.
With regards to the spring balance mechanism, I've attached a PDF that should have all the details you need. I didn't include anything on the wheel. Let me know if you need that.
Attachment 217645
ChristianLast edited by CGroves; 30th Jul 2012 at 03:14 PM. Reason: Fixed attachment
Similar Threads
-
VICTORIA Surface grinder
By ersbruce in forum METALWORK - Machinery, Equipment, MARKETReplies: 0Last Post: 5th Jun 2012, 02:19 PM -
Tripet Surface Grinder
By Anorak Bob in forum METALWORK GENERALReplies: 62Last Post: 16th May 2011, 04:57 PM -
surface grinder
By China in forum METALWORK GENERALReplies: 0Last Post: 19th Feb 2008, 12:48 AM -
surface grinder
By Arron in forum METALWORK GENERALReplies: 9Last Post: 16th Sep 2006, 11:43 AM -
Surface grinder
By steptoe in forum METALWORK GENERALReplies: 0Last Post: 10th Jun 2005, 12:21 PM