Member postings for Oily Rag

Martin - I have sent you a PM.

These taps are, I suspect, as used in some BSA gunsight mechanisms.

To set centre height accurately bring the tool up to contact the outside diameter of the work, back it off and slip a 6" rule (metric optional!) or a piece of old hacksaw blade (after the teeth have been ground off) between the tool tip and work. If the rule/blade is vertical you are 'on centre', if it is pointing away from you the tool is too high, if it points towards you then the tool is too low. This refers to the upper part of the rule/blade obviously.

This is a quick, easy and simple test for tool height taught to me when doing my apprenticeship - I always use this method. It can also be used for centreing work under a pedestal drill for cross drilling round bar. In this instance the rule/blade should be horizontal.

Whoops - Stuart beat me too it!

Edited By Oily Rag on 22/08/2023 18:14:58

One more photo showing all the components stripped out:-

Here are the photo's as promised!

I see you maybe looking for something a little less robust than this unit though, it transmits about 3 hp!

This is the original .unit, my replica is virtually identical but has some modifications and is made in EN40B and nitrided

I recently made a 3/16" 'sprag' clutch using 5 off 3/16" rollers 1/2" long. Fairly easy to make with a rotary table offset from centreline to generate the roller ramps. This was to replicate a starter system on a Jaguar XJR15, I was unsuccesful in discovering the original suppliers but suspect it was an American helicopter part (it utilised a 'helicopter shaft' coupling to connect the remote mounted starter motor to the Bendix starter gear)

Pictures to follow

Try Midland Abrasives Ltd, Hockley, Birmingham (0121 687 1135) - Very helpful people and will modify wheels to your requirements. I needed a new wheel for my toolpost grinder and they sent me one they had cut down from a metric size wheel as the original o/d was obsolete. This they did at no extra cost. They also recommend the grit and bond you require if you tell them what you are mainly interested in grinding.

No connections other than a very satisfied customer.

Martin

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Edited By Oily Rag on 11/08/2023 20:53:25

Edited By Oily Rag on 11/08/2023 20:53:59

OM - Yes I go along with that, by swoping the cutter around I should get the identical angle for second set of helical teeth. The Clarkson can cater for the helix angle with no problem.

BD2 - That is a good video on the basics. I've previously sharpened similar cutters to that in the video with no problems; its the catering for the helix that caused me to hesitate and ask for any advice that others may have been here and done it. My Clarkson has a range of spindle detents formed on the rear retainer ring for varying numbers of teeth but as you say some cutters have non uniform teeth for chatter prevention and to stop tri-lobing of reamed holes where 6 teeth can create a problem. I've never seen the page, shown in the video, with the information chart for cutter wheel size vs grindstone diameter and off sets to apply for land and angle. Does anyone have a scan of that page by any chance??

TP1 - I have the ability to index off the cutter teeth, or as mentioned previously, off the cutter arbor spindle retaining ring. the tooth stagger does look even though.

Thanks all for your inputs

Martin

Thanks DMB for your thoughts.

Your description matches what I was considering. I think I need a small cup wheel and set the cutter up with the 'nose' down at the helix angle and then traverse the cutter across the cup. after sharpening 15 of the teeth I can then turn the cutter around on itself and repeat for the alternate teeth.

I'll give it a go and report back!

Martin

View of the cutter showing the reversed 'helix' on alternate teeth. 15 x 2 teeth on the cutter. Note the lack of primary clearance where the cutter is rubbing in the bottom of the slot it is forming. Cutter is 3/16" wide x 3" dia x 1" bore.

Any one had the pleasure of regirinding a stagger toothed S&F milling cutter where the stagers have a very slight helix angle - each alternate tooth has the helx angle reversed? I have a Clarkson T&G so I should be able to accomodate the angles required (I hope!)

It apprears the primary clearance is insufficient at present, the tools is dragging at the bottom of the slot it is cutting and the primary land is showing this.

I can post a picture which may help in understanding my problem.

OM - That SP tool looks just like mine! the saw has to go over 4" through the head and it is impossible to seal it against water (coolant) as the lower end of the stud is within the block waterways.

Here is a picture of the tool and the job it did:-

It broke during use at the point where the 7/16th" drill ended, so we silver soldered it back together after turning a register on the solid part of the shank. The teeth were reground about 4 times on a Clarkson T&C grinder, so it finished up about an inch shorter than it started out.

This is a picture of the block with two of the sawn studs showing (this is 'A' Bank - we didn't have to cut any studs on 'B' bank after using the saw ). We used penetrating oil, acid, heating and cooling - all to no avail. As you can see the studs 'live' in with the coolant which doesn't help matters any!

Thanks for all your suggestions guys.

Regards,

Martin

Thanks everyone for their inputs.

Just to clarify the studs are sliding fits through the head being screwed into the block at their lower portion and they hold the head down by way of nuts bearing down on the external upper head face. There is no threading involved (other than the nuts which remove with no problem and the lower end of the studs which thread into the block - and hopefully stay there! )

Old Mart - the studs are 7/16th dia (~11mm) and the nominal clearance hole in the head is just slightly over 12mm. I'd forgotten about Sykes Pickavant. Can you tell me what the o/d is on the 7/16th tube saw please?

Hopper - we did look at a Rotabroach and we purchased their 12mm o/d broach but the internal dia was just 6 mm! I considered grinding it out to 11mm but decided there would not be much left as the flutes would disappear leaving just 'legs' - the tube saw needs to be about 4 1/2" long to get through the head.so any Rotabroach would need mounting on an extension tube.

J Hancock - we do not want to remove the studs or damage them as they are hard to replace, both physically (extracting them from the block is precarious ) and purchase wise ( £11.50 per stud ).

Jeff Dayman - novel idea! Again I had considered EDM and water cutting but as there are 14 studs per bank we would have to make a multi tool to attack all 14 studs in one go. Will an EDM system work solely on the front end of the tool and not 'short out' as the sleeve goes deeper between stud and head?

Again thanks to all for responding to my question - all food for further thought.

Martin

David George - That sounds like a promising avenue to investigate. glass diamond hole cutter! Have you got a link please to a manufacturer / supplier?

One of the problems of working on older IC engines is in removing the cylinder head where a steel stud passes through the head casting. There is a heavy tendency for the stud to corrode through galvanic action and this is not helped by the seepage of coolant into the stud passageway.

Recently we were removing a head from a Jaguar V12 engine and had to resort to sawing through 4 of the 14 studs on one of the cylinder banks when the head refused to lift more than an inch or so. We have at our disposal a 'head puller' which consists of two one inch thick steel plates which bolt onto the head in place of the cam carrier and this then uses rods to press down on the exposed stud ends, thereby lifting the head away from the cylinder block.

Thinking back to my time working at Triumph Cars we had similar problems with the Triumph Slant 4 and V8 Stag engines and I remembered one of the fitters made a tube saw which went over the stud and into the stud hole in the casting to remove the corrosion.

This led me to make a stud 'tube saw' which was made from a 12mm silver steel bar with a 7/16" hole drilled up it - leaving a ~0.5mm wall thickness! After re-sharpening the teeth several times we eventually cut through the crud on all 14 studs on the other cylinder bank and the head released easily.

I am now considering making another tool from a higher grade of tool steel (D2?) and also considering a diamond plating on the tip of the saw to replace the tooth form.

My question is - has anyone knowledge of a company that can diamond plate a tool? Is there any known supplier of D2 tool steel in tube form (it doesn't have to be exact sizes as we can machine to finish size )?

Martin

Thanks for the responses guys.

I sort of thought it was a graphite grease, but it has a very sticky consistency which is more akin to an 'anti seize' compound rather like the American product 'Never Seze' as mentioned by OM.

The Bakers Fluid tin is in surprisingly good condition - it was wrapped up in a paper bag inside a plastic bag so has not had much exposure to 'dew points' I'm assuming. I might use a picture of it as my Avatar seeing as there is a connection with my 'handle'.

Martin

I was recently given the contents of a shed by a friend whose Father In Law had passed away. Among the treasures such as Whit nuts and bolts, machine washers, unused paint brushes (artists type) was a selection of old tins. Of the tins I was pleased to find a new unopened tin of Bakers fluid, some solder flux and solder paint and a Rocol tin of Ragoline.

It looks like a graphite grease but maybe someone here on the forum remembers this product as a cutting compound or anti seize product?. The tin is very old (probably by the style of writing mid '50's ) and I have never seen anything similar. Any ideas?

Martin

Roger, Howard, Ian,

The ring gear to starter ratio is 5.7:1 - this is because the flywheel / clutch assembly is a 5" diameter multi plate unit and the ring gear has just 57 teeth (starter pinion being a standard 10DP 10 tooth item ). It is therefore impossible to tuck the starter motor in close enough to the flywheel, hence the remote mounting of the SM.

We have now sourced the parts which will allow us to replicate the original. I found a Ball & Claw UJ at a local Engineers Suppliers which was gathering dust on their shelves and it appears to be a far more robust item than the cross pinned Hook(e) joint [Thanks Ian for reminding me of the correct spelling of that]. The new UJ is very slightly heavier than the original (+ 25grm ) but the mass of the system is low as the shafts are High Tensile tubes not solid shafts. This keeps the mass of the connection low to allow the rotational and for and aft movements.

The next problem has been removing the scavenge filters from the sump plate, had to make a tool to engage with the slots in the threaded bosses which have gauze 'socks' soldered onto them. Two came out fairly easily but the third was very tight. Any suggestions for a supplier of 50 mesh gauze (i.e 50 strands per inch = nominal 0.020" square 'free space' ) in brass, or bronze (steel as a distant third or even stainless if it is possible to solder! ). The bosses were threaded 7/8" UNF x 14 tpi made in steel but I'm considering replicating these in brass, suggestions please therefore, for a suitable grade of brass that solders easily and is reasonably acid resistant.

Thanks for your replies, in anticipation of your suggestions!

Martin

Edited By Oily Rag on 05/02/2022 13:13:44

Ha! Not bad guesses.

Although the Cosworth DFV was the first engine in over 60 years to be designed with no visible method of starting it! The HB was started via a shaft up it's a55 (through the gearbox ) as was all the Judd's with the exception of the KV 3000 engine and the reworked ex F1 V10 GV 3.5 litre when opened up to 4 litre for sports car racing and designated the MV. These used a system similar to that as we used on the XJR 15. The hand held starters were either 24V lorry units running off a step up to 48v or 36v after initialisation at 24v. Alternative start systems were compressed air starters with two speed running (to prime and then fast spin ).

Martin

Thanks for the many replies Gents!

Just to define the system a little more - The starter motor is a high performance high torque geared unit, the Bendix scroll is mounted in the end of the starter motor (just visible in the last photo looking down the block ). So, the way this operates is for the motor on energisation to push the whole of the remote shaft forwards and the pinion then engages with the ring gear and spins the engine up. The bracket shown at the front of the engine allows/supports the sprag clutch system and there is also an outer support for the pinion which fits into a bush in the bell housing. The PB bush in the housing photo below is very worn which hasn't helped the shaft alignment.

This engine is being restored after it had been 'mullered' by some unknowing mechanics when it was in Japan. The lower hook joint in the system had worn badly and damaged the bracket housing:-

The damage on the sprag support bracket caused by the lower hook joint.

The repair that had been done was that the 4 outer bolts had stripped the threads in the block and the answer they used was to put Nylok nuts on the inside of the block! (which meant the sump had to be removed to access the nuts ) not surprisingly the Nyloks (two of them ) were found lose in the sump when we stripped the engine!

We have now Helicoiled the threads and cross drilled and wirelocked the Allen screws. The dowels were also opened up to a larger size and are secured (by step drilling on the inside and by covering them with the lock wire run )

The car is a JaguarSport XJR15 road car of which only 42 were made. The engine is a 7.3litre Jaguar V12 (a stroked version of the JaguarSport XJRS 6 litre V12 ). This car was the Chassis development Prototype.

We have now identified a suitable sprag clutch arrangement which we can utilise (Reynolds Machine Tool division SO/SX series ) and we think we have found a suitable small hook joint system that has needle rollers. Available from WDS engineering supplies. But I'm still keen to find a UJ which has the ball and claw system. I am in contact with numerous ex colleagues at TWR, so I am getting assistance from their log books as well as my own, all helping to jog a 30 year old memory of these parts. The original UJ's were Dayton #20271 MTX - 5.771 DM. These we believe were American sourced and probably helicopter linkage parts.

A further part of the project is to build a replica engine based on this unit as a 'spare'.

Martin

Gents,

I am currently involved in the restoration of the engine for a rare car from the early 1990's. The engine uses a remote start system where due to space limitations the starter motor is mounted some way from the rear of the engine. To enable the starter pinion to engage with the ring gear, this starter system uses a long shaft (almost 16" long) with two hook joints and also has a one way sprag clutch onto which the 10T ring gear pinion mounts.

What I am looking for is a better hook joint than the current pin type system, the type I'm thinking of is the 'ball and claw' type often seen on machine tools (particularly table drives for milling machines ) as I believe this type does not have a very pronounced cyclic speed error.

The other item I'm looking for is a replacement for the drive sprag clutch into which the starter pinion fits. The motor operates by the usual Bendix gear which moves the pinion into mesh with the ring gear, but it would appear that the sprag clutch is there to protect against a 'backfire' which would (and does!) wreck the long drive shaft from the remote starter motor.

Here are some pictures of the current parts:-

Flywheel end of the system, shaft is 3/4" diameter.

The sprag clutch with starter pinion mounted

End view of the 'sprag' with the only markings on the component

The end which connects to the remotely mounted starter motor

A view down the length of the block showing the sprag clutch mount in the foreground and the starter motor (mounted by the blue anodised bracket ) in the rear area.

Thanks for any help / assistance / suggestions / cups of tea / and sympathy offered.

Martin

Andrew,

I've just noticed your posting about this Raglan Capstan machine. This looks to be a very rare powered capstan model. It has two electro magnetic clutches inside the headstock and this allows instant speed changes to be accomplished for capstan work. I have some pictures of the insides of the headstock and a diagram of the headstock arrangement. These are like no other Raglan machine and was intended purely for capstan type work.

I believe the spindle may also be the 'LOO' type with a taper register, not the threaded type nose as used by 'normal' Raglans,

The way these capstans work was to set them up for mass production of small items (bolts, nuts, studs, short turned specials) To cut a thread for instance requires a Coventry style Die Head with corresponding dies of the correct thread, the cross slide operates as a fixed chamfer and cut off slide. There is only a power shaft at the front of the bed to power the capstan.

A very desirable machine - but only if you want to produce 500 1/4" UNF studs!

Martin