Here is a list of all the postings DC31k has made in our forums. Click on a thread name to jump to the thread.
|Thread: Mystery Inspection Item|
Perhaps you might look at this auction:
Pay particular attention to the position, colour and design of the rule in the picture and the drainpipe on LHS. You may have seen them before...
Used for very small woodworking joints then?
The pieces differ in length by 120mm. I would be interested to see a micrometer that has this range of motion as the usual ones operate over 25mm or 1".
The head off one would be good for a lathe carriage stop or a milling machine length or depth stop.
|Thread: Motorising the feed screw|
Using a stepper motor for this is rather overkill, especially as you say your Arduino skills are developing.
The whole point of a stepper is that it gives you positional/angular control. All you need is variable speed. This is more simply achieved using a DC motor (coupled to a reduction gearbox as necessary) and the ubiquitous PWM speed controller.
If you really want to go Arduino, take it in small bites. Put a potentiometer on the analogue inputs to the chip and work out how to send from 0 to 255 to your screen.
Then investigate how to drive a stepper motor at a fixed speed from the Arduino (there are pre-written libraries that do this - all you have to do is give them two numbers: direction and speed).
Then glue the first and second together.
|Thread: Height Gauge|
Where it says:-
might be slightly at odds with his requirement for an imperial one.
Is the eBay one imperial?
|Thread: Mystery Inspection Item|
Somebody else has one anyway
(seller has quite a few for sale. The numbers appear to be half their length).
|Thread: power feed for miller|
If it is AC, it does not matter which you connect to live or neutral, but US wiring uses black for live.
As John says, you need a transformer. A standard yellow building site one is cheap.
|Thread: Pinnacle bench drill chuck key|
Have a look at:
to see if they help.
Also, if the keys you have either mesh too tightly or too loosely, you can press the sleeve on or off to adjust. See:
|Thread: Rotary Table Choice 36:1 o 90:1|
I have just picked a rusty M6 bolt from my stock and welded a 70mm dia. piece of steel to the end of it.
The piece of steel happens to have 200 equally-spaced marks around its perimeter.
This means it has a resolution of 0.005mm so it must be more accurate than my Mitutoyo micrometer as this only has a resolution of 0.01mm...
If (and I repeat, if) you go down the route of adding dividing plates to it, you will almost surely have to calculate all the plate and hole numbers for the 36:1 ratio table.
In contrast, you can find many published/printed information tables for a 90:1 ratio device (though some have errors).
The maths is not hard but if it is not your desire to do the calculations, that might be a small point against the 36:1 device.
|Thread: Bantam thread cutting set-up?|
I am assuming it is a native imperial machine (i.e. 4tpi leadscrew).
When screwcutting imperial threads, you use only one of the 120/127 pair. It is used only as an idler gear so does not change the ratio. Thus either one of the two is OK to use.
When screwcutting metric threads, you need to use both gears as a compound gear. This provides the necessary imperial to metric conversion factor.
|Thread: Facing bar ends parallel on the lathe.|
Have a look on the Stub Mandrel site for Schlessinger's work and then you will know rather than merely believe.
|Thread: Colchester chipmaster variant|
If you call the item by its correct name, a variator, you will have more success in your online searches.
There is a madmodder thread on disassembly and fettling, as well as one on Practical Machinist.
Two commercial sources, should you need them, are Allspeeds and Nottingham Electrical Transmissions.
As well as the factory manuals which Stuart will no doubt avail you of, download the Harrison 10AA manual from
as this has a section on variator maintenance.
|Thread: Colchester master gear 56T|
The gear you require surely has to mesh with at least one other gear.
You can find the details of the one you want from the one you have.
The width will be the same as the meshing gear.
If you tell us the number of teeth and outside diameter of the meshing gear, we can calculate the gear specification and tell you the measurements for the one you need as well as the cutter that will produce it.
|Thread: Milling Insert Clarification|
|Thread: CNC Gear Hobber|
Put 'stevenson gear hobber' into Google.
Read and digest everything you find (including the back issues of MEW).
Then you will be in a better position to understand the state of the art and crucially the boundaries/limitations of the method. It is this understanding, more than anything else, that will determine the success or failure of your venture.
Look at the electronic leadscrew thread here and on YT. Same basic principle of electronic gears rather than mechanical gears.
Software and encoders are 'industrial Lego' and are easily replaced.
|Thread: Wohlhaupter UPA4 Boring and Facing Head Operation|
That is why the manufacturer produces two manuals only. The first covers UPA1, 2 & 3. The second covers 4, 5, 6 & 7.
Maybe less brief:
Possibility of help:
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