Living with the Worden

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Background

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I have been the proud owner of a Worden Tool and Cutter Grinder, Ref.1 for some time now and, as with most tools we use, various things are done over time to make for easier use or to provide added facility.

What follows is by no means meant as a criticism of the tool, its accessories or of its design, but is a description of what I have done to satisfy my personal requirements. These findings are passed on for the information of other users who might find some aspects of interest, or worthy of consideration for their own use.

Dust control

One of the first considerations was to address the dust problem caused by the motor fan blowing air forward onto the table parts, photo 1.

This wheel guard was described in Model Engineers’ Workshop Issue 104. Although successful, a slight modification has since been made to facilitate my frequent changes of grinding wheels, photo 2.

This was merely attaching the front cover only and allowing the now open back to rotate about a hardboard disc pressed onto the boss at the front of the motor, photos 3 & 4.

This allows the guard to be simply pulled off to gain access to the wheel, or to replace it with an alternative, shorter guard for use with a disc type of wheel. It is easily rotated to either side of the wheel and the rear disc effectively stops any undesirable airflow.

Table control

The next modification was to provide controlled lateral movement of the table with a feed screw. This was described in Model Engineers’ Workshop Issue 122, photo 5. Although Hemingway Kits do provide such a screw adaptation, I preferred to use a quicker method of positioning the table to either side of the wheel and for the initial setting. As already stated, this method provides 4in. of instant movement and 4in. of controlled movement.

Accessories

I have made some of the supplied accessories for the grinder, namely the four-facet drill jig and the slitting saw jig, Ref. 1. It was whilst seeking advice on making these jigs from Kirk Burwell of Hemingway Kits that we discussed why it was necessary to make another work slide to accommodate the four-facet jig. He suggested that as I had all the bits in front of me, I could explore the possibility of using only one work slide for all of the accessories.

Common work slide

The original work slide uses a 40 tpi screw against an inserted button to push the tool holder forward, photo 6, whereas the drill jig uses a captive 40 tpi feed screw working in a nut in the jig base, photo 7. As can be seen in the photos, there is a considerable difference in the location of the feed screw bearing block on these work slides.

The conclusion was to adopt the feed screw held in a bearing block as in the drill jig. This replaces the threaded block of the original work slide, and also to replace the button in the tool holder with an adapter to hold the nut for the feed screw, photo 8. Although ideally turning the knob clockwise should increase the cut, the thread would have had to be made left handed. In practise, turning the ‘wrong’ way isn’t really a problem as only tiny increments are used during grinding. Is this any different from the subtractive cuts put on when boring in the lathe; which we all do without any problem ?

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It was also decided to incorporate a Zero adjustable scale on the feed screw knob, photo 9. The numbers on the collar were stamped in the appropriate direction. It will be noted that due to the design of the various accessories, the distance from the bearing block varies. This variation is accommodated by making the respective adapters of a length to suit.

Once made and fitted, it is only necessary to release the grub screw in the adapter to allow the accessory to be slid off the feed nut which remains in place on the feed screw, and slide the next accessory onto the nut, locking it with the grub screw. The slide locking bolt fitted to the left-hand guide of the drill jig slide was also transferred to the work slide, as the normal lock screw strap has to be removed to fit some of the attachments. In fact this could now be left off altogether. The feed screw locking method was retained.

Having passed my conclusions on to Kirk, he very kindly adopted my modification and produced a CAD drawing for an adapter kit, which he intends to supply (HK 1300W).

The slitting saw jig

The slitting saw jig, Figs. 1 to 7 used a piece of 1in. x 1/4in. flat stock to provide the tenon guide in the Work Slide. It was found on completion that with the work table horizontal and a saw blade fitted, the teeth were a significant distance below the centreline of the grinding wheel.

This was easily overcome by replacing the tenon with a piece of 1in. square material to bring the saw to centre height, photo 10. The tapped holes for the blade-retaining stud were replaced with a slot and a rebate to hold an M6 hex bolt captive, Fig 1.

This allows the teeth to have the closest support for various blade diameters, ranging from 3/4in. to 4in., photos 11-13.

Drill Grinding Jig

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When I started using the four-facet drill grinding jig, it was found that the table had to be pulled right forward and there was a conflict with the drill clamping screw and the grinding wheel, photo 14.

Reducing the height of the clamp screw bracket and moving the V block back level with its support plate resolved this, photo 15. Although reducing the effective length of the drill clamping arrangement, this has not detracted from its use with large drills. I did however find the indexing collars a bit tedious as when rotating the drill for the next lip, any slight movement of the collar caused one of the screws to loosen and the length setting was lost. The insertion of a small steel ball between the lock screw and the V pad with some firm tightening cured this tendency.

Alternative Drill Jig

Although the jig is effective for the intended purpose, it is limited to a single angle and will not cope with short drills or centre drills. While wondering what to do with the triangular off-cut from the drill jig body, I came up with a jig adjustable to any angle from 0 to 90deg., photo 16, that will hold and index anything from a centre drill, photo 17 to a 1/2in. drill, photo 18, Figs 8 to 20.

Following the advice of ‘Blind Pugh’ in his excellent articles on Tool-Room Topics, I have since produced a set of both countersink and flat bottom drills with this jig for use with the Allen screws I commonly use, photo 19.

Vertical Slide

It was felt that there was a need for some form of controlled height adjustment to ease some grinding operations, and a vertical slide type of attachment was made, which was also quickly interchangeable, photo 20, Figs 21 to 41 and vertical slide GA.

The original Spindle had a 1/2in. bore to take various split adapters and drill chucks on suitable arbors, photo 21. This has now been supplemented with a spindle bored to take the Collets from my Cowells lathe, photos 22 & 23.

The controlled and full free rotation of the spindle, allows the grinding of such items as end mill side teeth, a new lead on a broken/worn tap, accurate punch and scriber points or any item requiring accurate rotation against the grinding wheel.

	Vertical slide parts list
Fig 21	Base slide	BMS – 1in. x 1/4in
Fig 22	Feed screw bearing block	BMS – 1in. x 3/4in
Fig 23	Slide base	BMS – 1 1/2in. x 3/4in
Fig 24	Feedscrew bearing plate	BMS – 1 1/2in. x 1/4in
Fig 25	Feed screw	FCMS – 1/4in. diameter
Fig 26	Feed knob	Brass – 1in. diameter
Fig 27	Slide block	BMS – 1 1/2in. x 1 1/4in
Fig 28	Spindle	PGMS – 5/8in. diameter
Fig 29	Spindle knob	Brass 1in. diameter
Fig 30	Slide lock screw	Brass 1/2in. diameter
Fig 31	Tooth rest lock screw	Brass 1/2in. diameter
Fig 32	Spindle lock screw	Brass 1/2in. diameter
Fig 33	Cam plate lock screw	Brass 1/2in. diameter
Fig 34	Cam plate	BMS 1in. x 1/8in.
Fig 35	Tooth rest block	BMS – 1/2in. square
Fig 36	Tooth rest block spindle	FCMS – 5/16in. diameter
Fig 37	Tooth rest spindle	FCMS – 5/16in. diameter
Fig 38	Tooth rest	Hacksaw blade
Fig 39	Index ring	FCMS – 1in. diameter
Fig 40	Cam follower	FCMS – 1in. diameter
Fig 41	Cam follower	FCMS – 1in. diameter

Second Lathe Tool Holder

When making or sharpening the ends of lathe tools I found that when the Work Slide was set at 90deg. to the wheel, there was no means of applying a controlled in-feed to the tool bit. This has been resolved with a new Tool Holder with the slot extending along both sides to allow the cut to be applied with the feed screw, photo 24.

Radius Table

In order to grind radii of a known dimension on the end of lathe tools, I produced an auxiliary semi circular table to fit onto the Work Slide, photo 25. In use the table is brought up to the grinding wheel and the feed collar zeroed. The table is then withdrawn by the required radius with the feed screw and the tool mounted to just touch the wheel. When grinding is started, the tool holder is moved back and forth following the curve of the table.

The radius at the point of contact with tool to wheel remains constant and further cut is applied with the screw bearing on the rear of the tool, until the amount of radius required is formed on the end of the tool. This sounds fiddly, but in practice accurate radii can be imparted onto form tools very quickly. Figs 42 to 53 and radius table GA.

	Radius table parts list
Fig 42	Slide Base	BMS – 1in. x 1/4in.
Fig 43	Feed screw bearing	BMS -1in. x 3/4in.
Fig 44	Table pillar	FCMS – 1in. diameter
Fig 45	Table	3mm Sheet – 3in. x 1 1/2in.
Fig 46	Table guide	BMS – 1 1/2in. x 3/4in,
Fig 47	Tool holder	BMS – angle 1in. x 1/8in.
Fig 48	Tool clamp	BMS – 1/2in. x 1/4in.
Fig 49	Feed nut	FCMS – 1/2in. diameter
Fig 50	Clamp screw	FCMS – 3/8in. diameter
Fig 51	Feed screw	FCMS – 3/8in. diameter
Fig 52	Tool holder clamp	FCMS – 1/2in. diameter
Fig 53	Clamp handle	FCMS – 1/8in. diameter

4 facet Drill Grinding Jig HK 1310

Slitting Saw Grinding Attachment HK 1306

The above items are available from Hemingway kits.

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