|Thread: Is a hand scraper pulled or pushed?|
Posted by Pete Rimmer on 21/08/2020 22:11:13
Bill, use a 1500 grit disc at 400rpm or less. You'll get a great cutting edge. your 3000 grit disc is too fine and the 1500 will give a huge improvement IMO.
Cheers Pete, I was running about 350rpm from what I remember.
I'd used a 1500 grit to shape it originally and then swapped to the 3000 for a final finish and to touch up/re-hone the edge.
Genuine question, as I'm very much learning, but why are you suggesting a 1500 for the final finish?
I'd actually read elsewhere to lap even finer after 3000 with diamond paste to a mirror finish.
I spent a good proportion of lockdown pushing a couple of homemade ones; I'm certainly no expert, and had never really tried scraping before.
This was the setup I used for sharpening them on a 3000 grit diamond lap; They really do need to be sharp to cut without too much effort.
As I learned to my cost, the grade of carbide is quite important too; the smaller one worked well and held an edge OK, whereas the left hand one in the top photo is a carbide milling insert, which took an edge OK, but didn't hold it for long at all.
I later made a 3rd one using the same type of carbide blade as the right hand one, but cut in half and silver soldered across the end of a piece of stainless bar, to give a 25mm, rather than a 10mm cutting edge.
The rest of the album is HERE
p.s. Here's quite a good video of the basics
Edited By peak4 on 21/08/2020 22:06:21
|Thread: My wife broke the internet|
The other alternative, to preclude a future problem, would be to replace the master socket faceplate with an ADSL one, assuming you have conventional copper broadband, and your ADSL router is plugged into the master socket.
This new faceplate includes a filter, so all downstream phone wiring no longer requires a filter.
Further to that, the incoming cable pair terminates in the backbox and has a test socket; the new faceplate plugs into that test socket. The internal house wiring to your extension socket(s) is connected to the faceplate.
This means, that should you suspect a line fault, i.e. no dial tone, you can remove the ADSL faceplate, and plug a test telephone directly into the test socket. If the phone now works, the incoming wiring is OK and your fault is internal to the house.
If you just called out an engineer to fix the line, and the fault proved to be internal, you would likely be charged for the visit.
Also when fault finding, note that the ADSL will work down one leg of the phone line, albeit at reduced speed, whereas dial tone needs both legs.
|Thread: TurboCAD Forum - Has It Gorn?|
The last snapshot taken by the internet archive was December last year.
The latest post in that snapshot was August last year.
Not entirely sure what that tells you though as It could have still been active, with new contributions, later than that, but no archive taken.
On the other hand, maybe it was dormant from August, hence no further snapshots taken.
|Thread: Sharpening Files|
Posted by Speedy Builder5 on 14/05/2020 17:11:49
Peak 4 Bill, that link brings me back to the current post, but I do remember a post was written about a year ago on this same subject, but I can't find it.
A bit of a thread resurrection, but I found this one whilst trying to find the one to which I was actually referring.
Looks like I added a duff link this time, THIS is where I had intended to re-direct.
Only added this to clear up a duff link in case anyone else comes across it when searching.
|Thread: Height Gauge|
Depending on what style you want and budget, there's This One on ebay at the moment.
|Thread: Large left hand tap|
Split post as the previous was too long.
I also have a couple of wheels with a 2" bore, which will allow me to use a simpler design of two parts held together with a ring of bolts, as there should be space within the 2" bore to accommodate them.
These are actually 1" thick, which is oversize for this machine really, but it also means that they won't fit the existing holder, even with a bore spacer.
Similarly I have a couple of diamond wheels, with 32mm bore, which are obviously solid aluminium, so I can knock up a permanent adaptor for each. I've got a large lump of alloy in stock somewhere.
Hope this clears up the various queries;
I'll probably just do it all the normal way on the lathe, but thought someone might know of a source of L/H 7/8" BSP taps, or similar alternative but with a finer thread ideally, which would come in just undersize for the 1¼" as per existing, albeit with a coarser thread. Certainly isn't worth me shelling out £85 for a convenience factor, or even £30-£40 for a lump of silver steel, the rest of which I'd likely never use.
Sorry folks, I thought I'd been clear enough in my initial description, but the problem is the same as always without a proper proofreader.
I can visualise what I was saying, I've got the parts to which I was referring as well as a mental picture, but it's obviously not clear the way I worded the question(s)
Firstly, I've never suggested tapping anything from scratch, merely cleaning up a roughed out thread(s) I'd already cut in the lathe, to make sure it's not "drunken"; I'm quite happy cutting left hand internal threads, though it's not something I've had the need to do very often.
Oily, or Mr Rag if you prefer, on my Clarkson, as you say, there is a left hand ½" BSF thread, which you use with appropriate spacers etc to fix the wheel, exactly in the manner you describe.
I've actually made several extended carriers, duplicating the main spindle, so I can have several different wheels ready mounted.
The little Herbert surface grinder works slightly differently; probably more akin to other surface grinders, and the wheel is held in a demountable carrier.
It's only got a 6" wheel capacity, and the normal bore size seems to be either 1¼" or 32mm, depending on the wheel material and source. Unfortunately, some vendors seem to think the two sizes are interchangeable, and don't always supply what's expected/advertised.
Keith, many thanks for your link, most useful.
My intention is to make a number of carriers, so I don't have to re-balance the wheel/carrier combination every time I change wheels. There will be more than one design, but for the time being I'll more or less duplicate the one which came with the machine in both 1¼" and 32mm.
Here's the disassembled wheel carrier;
Left to Right; wheel carrier/rear flange - front flange - securing ring/nut
The "Top Hat" on the left has a parallel section 1¼" to suit the bore of the wheel, the front flange/washer is keyed, and also has a different depth recess each side to accommodate either ½" or ¾" wheels.
The washer/flange is actually a very loose fit on the bore size; I don't know if it's original, intentional, or just poor engineering.
That said, I've found that by offsetting it slightly from central, I can use it for balancing the wheel; this design of carrier doesn't allow any other obvious method, and I'm not experienced enough, or comfortable doing it the old way with a masonry bit.
The right hand item holds everything together. I've actually made a spacer so I can use a ¼" thick wheel as well.
The thread twixt left and right parts is undersize from 1¼" and actually measures at 1.22" @ 22tpi
This is the left hand thread I'll be cutting on both parts, as many times as the number of carriers of this style that I make.
The only reason for a tap was to smarten up and standardise the ID of the thread internal to the ring nut, so it's hardly essential, just time saving.
The rear of the top hat carrier also has a concentric ring cut into it, to act as a very basic labyrinth dust shield for the main spindle.
It has a through bore to suit the ¾" main spindle
The parts assembled ready to fit to the spindle;
As you can see, the main spindle has a step at the end, and the assembled carrier/wheel is retained by a single ½" L/H BSW nut and plain washer. (annoying as I already have a L/H BSF tap from when I made the Clarkson adaptors)
You can also see the triangular annular ridge which forms the other half of the dust excluder, this is on a static part, and doesn't rotate with the spindle.
Edited By peak4 on 13/08/2020 21:19:04
|Thread: Drill Sharpeners Compared.|
Posted by Clive Foster on 12/08/2020 23:21:47
Not quite. The grinder table angle is irrelevant. All that matters is that the drill is at the right angle to the grinding wheel to give the desired point angle.
The factory Clarkson set up has the table at 15° for drill sharpening because that makes calibration easier for the tap grinding function which has the table at a different angle anyway.
I sort of meant that, as I thought the base of the attachment was keyed to the slot in the table, with the photo showing the casting edge at apparently right angles.
Thanks for that Clive, the top view makes things a bit clearer.
I do have a Mk1 Clarkson T&C grinder that I obtained from a neighbour who runs the local skip hire company.
I've never seen their drill sharpening gizmo in real life, nor spotted one at a justifiable price for hobby use.
I've also got a Speetol tap lead attachment completely separate, so no real need for incorporating it into a drill sharpener.
We've discussed this before, but I'll post a link for other readers.
I've still not used it properly yet as I spent most of the local lockdown fettling the Herbert.
I get the idea roughly now, in that you set the drill cutting edge's included angle on the top table of the grinder and the pivoting action of the chuck off-axis provides the curved relief.
A short reply as I'm between courses of our tea.
|Thread: Cup grinder application|
Posted by Derek Lane on 12/08/2020 20:42:15
I could use a diamond on this machine as it has one grey wheel running at full grinder speed and a larger wheel running much slower which is for wet grinding. In which case I could run a diamond on the slow side and a white cup wheel on the higher speed side.
My next problem would be where to put it as three grinders in my small workshop could be a bit tight as it is only a 12' X 8' Shed it has got to the point that my two woodworking bandsaws now live in another shed.
If two of your grinders are the same, or similar, how about bolting them together, either side of a flip over shelf. That way it will only take up the worktop space of one, with the other stored hidden underneath, but without the need to fetch one from storage and swap them over.
Clive, not wishing to drag Derek's post too far off topic, but I was trying to find a K13 from a UK supplier like Chronos, but they, and others, only seem to sell the K12-4 jaw.
It is available on Amazon, but again ships from the far east.
Have you seen any designs around for a Clarkson style of the type you're thinking of?
By all means continue the discussion on a thread I started ages ago, to save swamping Derek's post.
|Thread: Large left hand tap|
Posted by Tony Pratt 1 on 12/08/2020 18:31:18
Yes I just re-read your post,I must be getting old
Don't worry, I know I am.
Just taken my glasses off to type this.
Posted by Brian Wood on 12/08/2020 16:43:38
Have you tried Tracy Tools in Dartmouth?
They are maybe your best bet for an unusual size and in left hand
Cheers Brian, but the closest are some metric ones @ £85 a pop
Other suppliers are also more expensive than I can justify for a one off job, albeit of several similar components.
The difficulty is the left hand aspect, a plain old 7/8" BSP is £9, but I think I have one of those anyway.
I appreciate I could use RH threads with a locknut, but was really looking to more or less duplicate my existing arbor.
I also have a couple of wheels (that came with the grinder) with a 2" bore, but I can sort them out with two flange plates and some bolts as there is enough space around a 2" wheel bore and a ¾" spindle diameter.
Edited By peak4 on 12/08/2020 17:06:12
Posted by Tony Pratt 1 on 12/08/2020 16:41:30
You could go the other way around & make the male 'bits' first all the same size & then use them as 'gauges to finish the females, I personally would use full form inserts on the threads & check the males with thread wires.
As for heat treat I wouldn't do it but leave the carriers/arbors soft, any heat treat is likely to add some distortion to your components, your really don't want this in grinding wheel arbors.
Tony, the comment about heat treating was intended to relate to a home made tap, rather than the wheel arbor.
I still need to make a trip over to Sheffield to collect some steel for the arbors.
|Thread: Cup grinder application|
I was looking to use one of these wheels on the little Herbert Junior I've just reassembled, again for drill sharpening, but probably with a reliance jig.
I did notice that some of the Chinese origin 6 jaw chucks have the long tapered, rather than stepped jaws, which might make them quite suitable for your Clarkson idea. I think they are Sanou K13,
I was looking at K13s for a different purpose, but none seem available with external jaws.
Edited By peak4 on 12/08/2020 15:56:24
|Thread: Large left hand tap|
Hello folks, I recently almost finished fettling a Herbert Junior surface grinder, and need to make some more wheel carriers, in both 32mm & 1¼".
The existing one is the normal "top hat" with a ¾" bore and a 1¼" parallel part to locate the wheel, all secured together with a left hand threaded "C spanner" collar and a large loose washer.
I thought the loose washer was just poor machining, until I realised it could be used for balancing the wheel with a bit of care.
Clearly I can cut both internal and external L/H threads in the lathe, but figured it would be easier to rough cut the internal one and finish off with a tap, so they were all the same size, and then use these to get the thread on the external parts OK as I make each one. (yes I'm being lazy).
The actual thread isn't important, other than on diameter and not too coarse.
Finding a tap at a reasonable price is the problem, and a lump of suitable steel to make one might not come cheap either, as well as the issues around heat treatment.
A 7/8" BSP Left Hand would probably do as well as a conventional 1¼" thread, but locating anything affordable seems to be an issue.
Anyone any thoughts?
|Thread: Cup grinder application|
Posted by Clive Foster on 12/08/2020 10:58:52
I added a spindle extension to the Clarkson to take one of these relatively inexpensive Axminster wide white wheels **LINK** for drill grinding duties. I'm well pleased with the results. Unfortunately out of stock for the next couple of weeks.
I was looking at those a little while ago, but currently been out of stock for some time, though I signed up for a re-stock update ages ago.
Unfortunately there's no actual spec for them on the web site.
Is there anything actually written on the wheel label please?
I'm thinking max RPM, and the actual grit size, bond etc. e.g. A46K7V
Edited By peak4 on 12/08/2020 14:30:16
|Thread: Thread identification|
From what I've read elsewhere, some of the threads used were specials.
It was argued that it was so that you had to buy spares from the manufacturer.
It seems to fall in between two model engineering 40tpi threads, so if you have Herbert chasers for one or the other, you could probably use the head itself to make them.
There's a table HERE
|Thread: Clarkson T&C grinder motor stopped|
I guess the two obvious questions are;
Does the motor spin OK by hand?
Does the Clarkson spindle spin OK by hand?
That should eliminate duff bearings
As regards the motor wiring box; I presume it;'s a dual voltage motor.
If it has the little brass bars to select the voltage, try removing them and measure the resistance on each coil individually.
That should give you some idea if there's one coil down.