Here is a list of all the postings Nick Hughes has made in our forums. Click on a thread name to jump to the thread.
|Thread: Hemingway Dynamic Toolpost Grinder|
This morning was Large Motor Pulley (For when internal grinding) time:-
A straight forward facing, turning, boring and reaming job.
Face aprox half the total stock, off what will be the back face,
After centre drilling for tailstock support, turned the O.D. to size and formed the belt groove. Followed by drilling, boring and reaming.
Then held in the 4 jaw and clocked true, faced to width, finish turned/faced the boss and recess,
On to broaching the 4mm keyway (Also did the smaller pulley machined earlier),
Always a relief when it fits,
Final job was to set the pulley up on the mill, and drill two 9.5mm holes, for access to the motor mounting bolts during belt tensioning.
Clock/Align to the spindle (Rotating the DTI around the boss) and set both X and Y to Zero, either on the machine dials (But remember the direction you approached the Zero point, so that you can allow for any baclash when pitching over to drill one of the holes), or on the DRO (no need to worry about backlash with a DRO)
And then simply pitched over both directioins in X, to Centre drill and then drill through,
That completes all the castings and so tomorrow (hangover permitting again) will be the Spindle.
Edited By Nick Hughes on 16/02/2019 16:24:21
Last weeks mission was the Cup Wheel guard and motor pulley:-
The single casting supplied makes the inner guard, outer guard and a small motor pulley.
Centred and rough turn the pulley
After boring and reaming, the belt grooves are cut (yes I do use HSS sometimes),
Then part off the motor pulley and reverse the casting in the chuck, to bore the outer guard,
Part off the bored outer cover and the remaining casting produces the inner guard,
The inner guard casting is turned to a sliding fit in the outer cover, faced to length and then parted off the chucking piece,
Setup the inner guard in the dividing head, to drill and tap the two outer cover clamping screw holes,
Then the outer sliding cover slots,
Checking the alignment before taking the outer guard off the dividing head, just in case there was some "adjustment" required to the slots.
The cutouts and mounting holes are then done in the same way as the previous External 3" wheel guards,
Lining up the cover for the rotary Zero degree starting point (after clocking the cover in to the rotary table and spindle) for the cutout. The inner guard was lined up in the same way,
Just the screws to shorten and then a radus to file on the open ends,
The final casting provided is for the Large motor pulley, but that will have to wait until next weekend.
Edited By Nick Hughes on 10/02/2019 13:24:49
Sunday afternoon, only slightly hungover:-
Clocking the inner guard bore, concentric to the rotary table axis, (the DTI is stationary and the table rotated),
Then clocking to the spindle axis (this time the DTI is rotated around the bore),
Next the outer 3 tapped holes. This used the DRO Circular Hole function for the positons and the hole to boss balance was achieved by lightly spotting each position and if needed, the table was used to rotate the part, the hole positions re-spotted and when an acceptable balance has been reached, the rotary table is clamped and the holes drilled, tapped and countersunk,
Without changing the angular position of the the rotary table, the inner countersunk mounting holes were completed, once again using the DRO function,
The outer cover was setup and drilled with clearance holes in the same manner (but without the inner countersunk holes).
On to the cutouts. The chuck jaws would foul the cutter and so the covers are clamped directly to the rotary table, then aligned in the same way as previously,
The outer cover has a 0.5" radius at the intersection/bottom of the cutout, so this was bored first,
Then one of the clamps is re-positioned and the sides milled to blend in with this radius,
The assembly so far,
Edited By Nick Hughes on 04/02/2019 19:04:14
|Thread: Where have all the C/S Copper rivets gone?|
For the UK, try contacting:- http://www.sapphireproducts.co.uk/index.htm
|Thread: Hemingway Dynamic Toolpost Grinder|
On with the External 3" Wheel Guard castings:-
Two identical castings are supplied and the machining converts one to the inner guard, by removing the boss,
Held internally, just to get started quickly,
A light facing cut (after the boss has been machined off), just enough to clean up the whole face.Then the casting is measured to work out how much to remove off each face (in this case the light skim was enough for this face)
Reversed and held externally, faced to length, then the internal features machined,
The outer guard is machined in the same way, only this time the boss is left on the casting,
Drilling and milling tomorrow, IF the hangover after tonight is not too bad!
Edited By Nick Hughes on 02/02/2019 12:59:57
Drilled and tapped for the lubrication nipple this morning:-
To centre the hole in a boss, I use a washer that is close to, or slightly smaller than the boss dia and with a drill shank or rod, that is a close fit in it's hole held in the chuck (use an ER Collet chuck if using a drill, as it holds on the drill flutes better), put the washer on the boss, lower the drill shank/rod into the washer hole (but keep it just clear of the boss face) and then simply move the table around until you are happy with the position, then drill as usual.
As my plan is to machine all of the cast items first, the next on my list are the Wheel Guards and I should be starting on these tomorrow.
Edited By Nick Hughes on 01/02/2019 10:55:15
This morning before setting off for my afternoon shift:-
Drilled and tapped the mounting holes for the Belt Guard/Motor Mount.
Clamped to the previously aligned angle plate (a bit higher this time to make access easier). Then clocked in the main bore and set this as both X and Y axis Zero,
The holes are drilled, tapped and chamfered using the DRO oblique line of holes function, in the same way as the cover previously.
Note the two types of Machine Taps. The Bright one on the right, is a Spiral Flute for the two furthest Blind holes and the Dark one on the left, is a Spiral Point, used on the nearest two through holes,
Thankfully the holes lined up,
Just the lubrication nipple hole boss, to face, drill and tap and another part will be finished,
Edited By Nick Hughes on 29/01/2019 12:14:27
Fridays job was to screwcut the thread for the retaining collar:-
Then using this expanding mandrel in the 28mm bore,
Finish faced the second face to achive the final overall length (used the power cross feed),
Then the height from compound slide face to spindle centre line was measured, using a turned bar and gauge blocks (slips),
Today was on to the compound slide mounting face:-
Clamped to a small angle plate and the cast face leveled,
Then after roughly centering the face with the spindle, the face was skimmed enough to clean up and provide a true face for the next operation,
After skimming, the part is clamped on to the machine table and after centering the boss under the spindle to a scribed centre point, the clamping stud clearance hole is drilled through into the cavity seen in the previous photo,
Next was to determin the amount of material, that needed to be removed, to bring the bore centreline in line with the lathes centreline.
This used the expanding mandrel from earlier, gauge blocks and a precision ground block to clamp the part down onto (V block in this case) and some arithmetic.
Then re-mount the part on the angle plate, level the face as before, centre under the spindle by clocking in the drilled hle from earlier, touch on the face and then remove the amount determined previously from the face,
After the face was completed, a smaller tool was fitted in the boring head, the cavity bored to diameter and faced to depth (clearance for the Myford four way toolpost ratchet if it's fitted),
Final operation for today:-
After clocking the angle plate parallel with the X axis (left to right), to act as the alignment datum for the next two operations. The previous mounting face is now held against the angle plate and the part clamped down on to the machine table, the bore aligned with the spindle by clocking in again.
Then the three M5 tapped mounting holes were machined using the machines DRO Circular Hole Pattern function.
Edited By Nick Hughes on 26/01/2019 18:13:15
Today was finish bore the two bearing bores (28mm & 32mm Dia).
Semi finish boring of both bores was checked for size, using a Telescopic Bore Gauge, leaving 0.2mm for finish boring :-
Set and lock an External Micrometer to the (28mm in this case) bearing outside diameter :-
Then use this to set the Bore Gauge ready for finish boring :-
Checking the finished bore for size (Bored to Bearing Dia plus 0.005mm), for the drawing stated "Tight push Fit" :-
The front 32mm bore was done in the same way and then a final skim of the front face :-
Edited By Nick Hughes on 22/01/2019 18:21:53
Started on the Spindle Housing this afternoon.
Only had enough time to rough bore though:-
|Thread: New collets. Bankrupt now.|
|Thread: Hemingway Dynamic Toolpost Grinder|
Last Saturday mornings initial hand work:-
Fettled the Inner Cover cast appeture (this is slightly out of position, but not enough to cause a problem). The two 3.2mm drills, are just acting as temporary aliignment dowels between the two covers and will be replaced once the covers are painted,
Then the Outer Cover (Removed the Logo, to make painting easier),
Followed by dressing the assembled covers,
There's a bit more work to do and some dinks to fill before painting. This will be done when all the remaining castings are machined.and finished to the same level.
Edited By Nick Hughes on 15/01/2019 11:10:35
I've had this kit for about 9 months and finally made a start on Jan 1st 2019.
First off the outer cover, clamped down lightly on 3 blocks, to machine the bosses.
After machining the bosses, the 3 blocks are clamped to the machine table and then the inverted cover stuck on to them with superglue
The joint face was then machined down to the drawing dimension, using 0.5mm/0.020" cuts and some breath holding
The inner cover was machined in a similar way, but no need for any superglue this time on the second face
As most of the holes in the inner cover are dimensioned using Polar Coordinates, I used the DRO functions for these and again to mill the radius slot.
This meant that (even though I have both a CNC mill and a 10" Rotary table for this manual mill) only the one setup was required.
More to come!
Edited By Nick Hughes on 10/01/2019 19:51:08
|Thread: What Did You Do Today 2019|
Started on my Dynamic Toolpost Grinder Kit from Heminway:-
(More immages in my "Dynamic Toolpost Grinder" Album)
I'll post progress on here and update the Album at the same time.
Edited By Nick Hughes on 01/01/2019 23:15:42
|Thread: Form tool to cut big end / main crank bearings.|
Relieve the centre of the tool, as shown in the first 3 min of this video:- **LINK**
Edited By Nick Hughes on 01/01/2019 19:36:07
|Thread: Wall Storage Recommendation|
Machine Mart have a range of all steel small part storage, with either 16, 25 or 36 drawers. An example:- **LINK**
Don't know if they can be directly wall mounted or not though.
Edited By Nick Hughes on 27/12/2018 19:05:25
|Thread: Bearing puller from hell|
Direct link:- **LINK**
|Thread: Learning CAD with Alibre Atom3D|
Check your "Inbox" I have sent you a message that might interest you.
|Thread: toolpost motor|
The Dynamic Toolpost Grinder kit I have from Hemingway, has a 250W, 2 pole motor.
|Thread: Any ideas anyone|
Roundhouse Engineering have a Steam Regulator, that may fit the bill.
On the website here:- http://www.roundhouse-eng.com/
Have a look in the drop down menu Roundhouse Products, then click on Parts and scroll down the Parts List to REGRC
Edited By Nick Hughes on 21/11/2018 11:56:19
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