Learners Project - Simple Grinding Rest

[Cogsy]

I like to leave just a little of the taper unless thread engagement is going to be low, just for looks - not that anyone can see when the engine is assembled anyway. Here's the head bolts on my Rupnow Vertical, somewhat styled after red Holden head bolts, these are M5 as well:

 

[goldstar31]

James
I notice that you have 'discovered' the failings of dies which are really designed to re-furbish worn threads. Ah well?

Probably the only wise solution is to screwcut and then use the incorrect die.

It does beg the question of whether your intended tool and cutter grinder will correct the small taper lead on dies or grind the proper cutting edges to worn dies.

If I recall, I DID suggest that you read Chaddock on his Quorn which deals with such matters. Of course, there are other solutions that come to mind.

Laughingly, I'm one of Imperial guys and metric screwcutting on an imperial lathe with an imperial gear box is- well, a so and so. Yea, got a 63 tooth and a pair of 21's and a metric banjo-- and no music for it:hDe:

Norm

 

[joco-nz]

Norm - The game plan is to get some proper button dies not these crap die nuts I have. That should help solve things. The grinding rest is not going to be of the capabilities of the Quorn, the casting for such a machine being rather pricy. But it should do well for the bulk of what I am looking to achieve in the tool grinding/sharpening space.

In the area of screw cutting, fortunately I have a metric lathe so metric threads are pretty straight forward. Imperial on the other hand seems to be a bit more approximate.

Cheers,
James.

 

[goldstar31]

Norm - The grinding rest is not going to be of the capabilities of the Quorn, the casting for such a machine being rather pricy. But it should do well for the bulk of what I am looking to achieve in the tool grinding/sharpening space.



Cheers,
James.

Surprisingly, the Quorn has been fabricated many times and in addition, the Bonelle is designed to replace the Quorn which is expensive- for what it is.

Probably( ?), the trick is to make up a Quorn spindle or failing this, the one for the Bonelle, or the Stent or in deed the Kennet.
All are a nominal 1" and will interchange--- and no castings!!!

Years before all this, I made up a tool post grinder which I had bought as a wood router. Further examination revealed that Robert Bosch had actually produced it as a tool post grinder. I'm not always unlucky!

Writing on a bit, there are several home made t&c's which have/had a router as the motive power.

It's an interesting subject

Regards

N

 

[joco-nz]

Norm - thanks for that as I was unaware of the Bonelle. Now I sourced metric plans and a build guide. Another project on the "must do as it's interesting" list. :thumbup:

 

[joco-nz]

I managed to borrow an nice HSS M5 button die from Bruce and decided to redo the last two threaded rods which had the nasty stripping of the thread on the first 5mm or so of the thread.

So here a series of pics of the first one I re did.

Pic #1:
Setup of the 6mm stock with support to be turned down to 5mm.


Pic #2:
Turned down and ready for threading.


Pic #3:
And a threading we will go.


Pic #4:
And the results. You can see the new part on the left. Nice clean thread with a good start right from the beginning. The one of the right is the original and you can see how rubbish the first ~5mm is. Stripped and just yuk.


Cheers,
James.

 

[joco-nz]

The final threads in all their glory. :thumbup:

Finished the long one tonight with my brand new HSS M5 button die. But after some TIG practice it just got too dang cold in the garage. So have to wait until tomorrow night for the next lot of stuff.

j.

 

[bazmak]

years ago I had a lathe I bought at home in the shed specifically to do
jobs for the co I worked for on the side.Paid for the lathe in no time
One particular repeat job was to put an M6 thread x 30mm lg on pieces
of 6mm round bar nom 400mm lg.Tried all ways to get good consistent threads
With a dieholder in the tailstock I pushed on the job and let it pull the die and tailstock the reverse and push off.Also tried with the die holder in the toolpost
and fed on to the bar at the correct screwcutting feed then reverse off.The carbon steel dies did not last long before stripping threads.Had to use HSS dies
which lasted longer.Learned very quickly the difference between Carbon steel dies and HSS. Now where possible I use HSS but for limited work CST sometimes suffices

 

[joco-nz]

A short update of some of the fiddly bits.

Pic #1:
Shows the threaded rods with their retention sleeves in place. These now need to secured properly in place. A mix of loctite and a pin should see these being pretty solid. Although I do have a half formed idea that a little TIG Brazing on the threaded side will hold stuff in place forever. But we shall see I'm probably at risk of over engineering things again. oh:
You can also see the locking rod with its little brass cap. That was a pain to make. Its 4mm wide with a 2.4mm shaft that inserts into the rod. The other rounds are the beginnings of the knobs that will go on the ends of these shafts.


pic #2:
This is a close up of the locking shaft with the brass insert installed.


Cheers,
James.

 

[joco-nz]

Okay I just couldn't stop. The knob blanks were sitting there in a very accusatory way. "Machine me ... machine ME ... MACHINE ME DAMMIT!!!"

Pic #1:
This is the setup used to machine the knobs. The toolmaker clamp provides a stop so I can turn the ER32 Hex block and reposition in exactly the same spot. The mill tool is an 8mm bull nose HSS bit. The knob blanks are 1215 engineering steel, 19.90mm round.


Pic #2:
The knobs all done other than the set screw holes. Things were getting a bit dang cold in the garage so that can be a tomorrow job. You might notice that the indents don't go all the way down the sides. There is a 3mm band still left intact, The idea is that at some point I will have the setup to put marks on the knobs. Given the threads is M5 x 0.8mm which means if I put 40 divisions on this I get 0.02mm travel per division.


Pic #3:
"Dry" fit up of the knobs with the various shafts. Starting to look more and more real. :thumbup:

 

[joco-nz]

Okay an update with the latest parts made.

This pic shows:
[1] The equal angle which will be the base. 32x32mm angle with a 110mm slot cut in it using standard chain drilling approach to remove the bulk of the material.

[2] three washes that are 3mm thick

[3] The M3 set screw visible on the knob

[4] The spacer between the black plastic ball and the central dovetail.

Cheers,
J.

 

[joco-nz]

A little bit done over the course of the week and today (Saturday). Progress while a bit slower than I would like, blasted work has a lot to answer for, but my learning curve hasn't helped either. Anyway on to the pics.

Pic #1 Setting up for drilling the cross pins to hold the 7mm retaining ring in place on the threaded shafts. The rings have been secured with loctite as will the pins be.


Pic #2: WIN - 1/16" holes drilled ready for the 1/16 Piano Wire I'm using to make the pins.


Pic #3: The raw pins in place


Pic #4: Pins ground back ready for a proper sanding


Pic #5: The bearing blocks that will hold the long fence feed screw in place.


Pic #6: The bearing block that will secure the dovetail feed screw positioned and ready to locate the drilling position of its securing screws.


Cheers,
James.

 

[joco-nz]

Managed to get some nice progress on the transport block that the fence will be mounted on and which will allow small adjustments of the fence position. Todays achievement was to get the blocked drilled and tapped to run on the M5 lead screw.
General process was:
[1] to get the block mounted in the mill vice vertically then aligned for drilling
[2] drill with 11/64 all the way through (total hole depth is 45mm)
[3] drill 25mm at 4.5mm to a depth of 25mm
[4] ream to 5mm to 25mm depth
[5] tap M5 all the way through on the remaining 11/64 sized hole using a tap wrench

The setup was not changed through the entire operation to ensure no alignment issues.

Pic 1 & 2:
Dry assembly showing the transport block on the lead screw with the knob and mounting blocks.



Pic 3:
Dry assembly on the underside of the grinding rest.


Cheers,
J.

 

[joco-nz]

A nice evening distressing in the garage. Decided to stop once it got to the point each breath was a puff of steam.

Pic #1:
The holes drilled, tapped M3 and the everything mounted up properly.


Pic #2:
The top of the table. You can see the transport block pocking through the slot. It now needs to have the fence mounting holes drilled and tapped.


Pic #3:
This shows how much the transport block is sticking through. This is intentional. I need to blue the sides and run a scrip along the sides flush with the top of the table. I can then mill down to that line and have the block nicely flush and ready for the fence to be mounted.


Cheers,
J.

 

[joco-nz]

Bit of an update from the last few days of making chips.

Basically we have the fence transport completed having the mounting holes for the fence drilled and tapped.
The full assembly of the grinding rest.
The completion of the fence other than the needed M5 screw to mount it to fence transport that I had forgotten to order but are now on their way.
The locking thumb screw on the fence that I made today. Just turned down from 10mm round then grips made with a 4mm end mill.

Pics 1 to 4: The grinding rest assembled. Still in need of a cleaning bath to get all the blue off. But that will happen soon enough.





Pic 5: The basic blank for the fence. You can see the M3 screw on the side at the front which acts as a stop.


Pic 6: The fence cleaned up and the locking thumb screw in place.


Pc 7: Close up of the thumb screw to try and show off the milled grips. Could probably do with a final cleaning facing pass to really clean up the top. But its perfectly functional and smooth as is.


Cheers,
James.

 

[joco-nz]

Oh and the ball clamping stand-off is currently getting "right sized" as at the moment it is clearly to big.

 

[joco-nz]

And here is the completed fence mounted on the grinding rest. Next will be nice mounting of the bench grinder along with the mounting positions for the grinding rest.

 

[joco-nz]

These are mockup pics of the grinding station. The base is 16mm thick melamine board cut to 600x600mm and a sandwich of two sheets glued together. The grinder is raised up by 18mm to get a better position for the rest and to allow more options on the vertical adjustment. Next will be to finalise the position, market for holes and the threaded inserts.

 

[goldstar31]

Hi James

Not seeing anything in your last posting either in Windows7 or my Mac.

My thoughts are about what can be deduced suggest that you will be frustrated with the nuts and bolts clamping which could be improved.

Meantime

Regards

Norman

 

[bruedney]

Yes I can see them