Author Topic: Article: The Missing Link, Virtual DW  (Read 6693 times)

0 Members and 1 Guest are viewing this topic.

Offline Doug

  • Global Moderator
  • ****
  • Join Date: Mar 2004
  • Posts: 3464
  • Location: Pennsylvania, USA
Article: The Missing Link, Virtual DW
« on: 07 Jun 2004 at 15:38 »
The missing Link, Virtual DW

I had always wondered where they had come up with the model designation EW, and if the initials stood for anything in particular.  Some sort of rationale seemed to be needed to explain the jump between the CW, last of shall we say classical 2-3/4hp models, and the all new 2-3/4hp EW.  After all there was no DW model.  Or was there?  Well it seems there was, as attentive readers of “The Best Twin” already know.  At least it existed to the extent design work and drawings were commenced.  And what an odd animal it would have been, a hybrid cross between a CW and the OB model.  Of the few drawings that survived, the reconstruction illustrated here is based to give some idea what might have been.  



Larger view here

It can be seen the petrol tank has become very much EW like.  Not completely as it still lacks the slot for the gear change.  The gate for this must have mounted off the frame, as there is no provision for such on the tank itself.  
The frame lug for the gearbox mounting is quite interesting.  Novel it is not to our eyes, but it is thrown forward quite a bit so the gearbox would clear the rake of the single rear frame down tube.  Also note it incorporates the rear mount for the petrol tank.  It would have been very pioneering at the time if the DW came first and introduced the gearbox mounted under the saddle, more of which anon.



Larger view here

The DW gearbox looks like OW/OB issue (but for one exception noted further on) or is it really the other way around?  The OW/OB24 gear case drawing 6441-5 (primary half) has a note to “use casting 6940” and that 6442-4 (final half) is to “use casting 6941”.  These references are in fact to the numbers for the DW drawings!  The DW gearcase drawings were done September 3rd (the frame lug on August 26th) yet those for the OW24/OB predate that considerably and are from January 1924.  This is a slight paradox, as the DW drawings are five hundred part numbers higher!  The geometry and position for all the views are clearly identical between the OW/OB and DW drawings.  One was traced off the other or both from the same master source.  All these changes to the OW/OB24 are reflected in the DW gear case drawing (or vice versa.)  The one exception is the boss provided is not machined for a lower shifter fork bushing in the DW.   Perhaps an oversight, as it would have been an appallingly bad design.  

Possibly the date on the OW/OB gear case drawing is when the drawing number, but not the tracing, first came into existence.  Most of the OW/OB drawings date from early 1924.  But it seems unlikely they would backdate the tracing so far and I would consider it unusual drafting practice unless noting separate drawn and traced dates.  More likely it is the date of the prior revision, as the drawing numbers are blacked out in the title block and the updated drawing numbers entered below.  This was a timesaver used when minor alterations could be done to the existing drawing, such as striking out or adding new information.  Unfortunately Douglas was not very dedicated in proper dating and delineating of revisions nor for that matter always indicating the date of drawing verses the date of tracing, and in some cases not providing any date!  They were on revision four and five respectively for the OW/OB ‘box, quite high as far as revisions go.  This could have placed them at the time of, or slightly after the DW drawings.  At which point the note to utilize the by then existing and perhaps surplus DW castings could have been added.  But as pointed out, even at the previous revision when it is assumed the views were laid out, the designs had converged even if the DW drawing did not yet exist.  

It looks as if initially there were other intentions for mounting the OW/OB gear case, which argue against it being first.  There are catalog specifications/adverts in “The Douglas Range, Volume 2” for the 1924 OW/OB that show a gearbox mounted in a similar position as the RA model.  That is, off of the crankcase and not the frame, and the description for the countershaft unit collaborates this.  Also there is an illustration for an bare OB/OW frame sans gearbox mount.  But there is also is an older Vintage and Veterans Restorations (Publishing) reprint of the 1924 catalog and this shows the OW/OB models with the gearbox most certainly attached to the frame, as one would expect!  It may be the OW/OB started out at the design stage with a transmission mounted like the RA, and then they changed their minds and mounted it off the frame as per the DW.  The (presumably earlier) catalog description, illustration, and the DW part numbers on the OW/OB drawing are strong arguments for this case.  And after all, they certainly were not going to mount the transmission off the crankcase of the DW!  One way or the other, by September the design was settled for both.  

The rear fork shows slight differences from the CW, changes being required by alteration of the main frame and its attachment to it.  Likewise the rear stay attaches to a totally different saddle lug.  What the rest of the frame looked like is not known.  Certainly the gearbox lug and the rear fork would mandate some additional frame components unique to the DW.  It would seem it was intended to fit a brake rim, judging by the lug provided.  

The engine has some minor changes, so minor one wonders why they bothered to make them at all.  The drawings state “Alteration to Standard 2-3/4hp Crankcase Timing* Half for engine on DW25 machine.”  (* Or “Flywheel”, as the case may be.)  So for the most part cover only details that were actually different.  This makes things a little more difficult in creating a virtual model, as I am not that terribly familiar with the 2-3/4hp models.  Perhaps someday if a bargain turns up!  

The oddest change would be a relocation of the crankcase joint offset.  Instead of being favored 1/4” off the cylinder barrel axis towards the timing side, it is now some 9/32” to the flywheel side.  This seems to be so to provide a location for a pair of 3/8-20 threaded bronze inserts in the magneto platform that would otherwise have straddled the joint had it not been relocated.  There is also a pair of small extensions to the crankcase to allow another pair of 5/16-18 tapped holes that would have otherwise been too widely spaced and fallen off the sides of the magneto platform.  Assuming one pair continues the function of holding down the magneto, what is the other pair for?  It is not a rectangular pattern and they are tapped differently, and I can only guess it was to accommodate two new and different styles of magneto from that previously fitted.  

Mention is made that the diagonal gallery to drain the sump can be removed from the pattern.  A simpler, though perhaps not as convenient to reach (behind the flywheel) drain plug is provided in the floor of the flywheel crankcase half.  This also has a lug added nearby clearly to provide a means of jacking the engine fore and aft for chain adjustment.  To be honest, I do not know if this is present on the standard 2-3/4hp though can not find a picture showing such.  The drawing gives the impression it is new.  

The engine clamps the lower frame member as before, but with two bolts passing through the frame tubing.   This must have been slotted, if the engine were to slide fore and aft to tension the primary chain (the gear case is fixed.)  Perhaps it was felt these slots were needed to keep the engine vertical as it was adjusted, and so the old way of four clamping bolts immediately above and below the frame tube was abandoned.  

It is probably a safe bet the DW was intended to use many of the parts left over from the venerable CW and TS models.  As it turned out, they outlived the DW!  But just how many parts were to be 'recycled' we may never know. I have resisted the temptation to ‘flesh out’ a probable representation of an entire machine.  Without a spares list or general arrangement drawing (unlikely either existed) it is impossible to say if an absent component is due to a missing drawing or reuse of a pre-existing part.  

Surviving TS/CW part numbers go up to 2088 as indicated by a March 1927 Spares list.  Many are below one thousand but at revision D, as befits the fact it is much the same 2-3/4hp that its sire was (and its sire’s sire!)  But there is a disparity, as the parts list shows one numbering scheme yet drawings indicate higher numbers were being used internal to the factory.  (This practice appears to have stopped with the EW.)  The highest known number definitely attributable to the CW24 is 6331, with 6374 a possibility.  But then there is a spate of numbers assigned to the OB known to run from 6659 through 6869, at least, mostly in May-July of 1924.  That is as the numbers indicate, right before the DW.  

Known DW part numbers are as follows.  Component numbers not appearing on their own drawing are indented following their assembly.  

No........Model........Description
6880.........DW25.......Gearbox lug, 26Aug24
c/6891......DW25........Rear stay, assembly, 11Jul24, struck out: c2/5630
..6891.......-...............Rear stay tube
..6892.......-...............Rear stay front lug
..6893.......-...............Rear stay back lug
c/6894.......DW25.......Rear fork, assembly, undated, struck out: c1/5631
..6374........RW/RA?....Rear fork brake lug.  Believed RW/RA part
..6888........-..............Rear fork distance piece
..6895........-..............Rear fork cross tube
..6896........-..............Rear fork lug
..6894........-..............Rear fork tube
..6899........-..............Rear fork lug
..6900........-..............Rear fork bolt
..6901........-..............Rear fork washer
c/6932.......DW24.......Rear stand assembly, 07Sep24
..6930........-..............Rear stand fitting
..6931........-..............Rear stand fitting
..6932........-..............Rear stand cross tube
..5217........CW/TS?....Tube, rear stand (vertical strut).  Believed CW/TS part
c/6934.......DW25.......Saddle bracket, assembly, 06Sep24
..6934........DW25.......Saddle bracket
..5398-1.....CW/TS?....Rod, saddle bracket.  Believed CW/TS part
6938..........DW25.......Crankcase, flywheel half, 02Sep24
6939..........DW25.......Crankcase, timing half, 01Sep24
6940..........DW24.......Gear case, primary half, 03Sep24
6941..........DW24.......Gear case, final drive half, 03Sep24
ca/6969.....DW25........Petrol tank assembly complete, 20Aug24.  Components for tank listed as “standard”, i.e.: filler caps, pump body, tank supports.  Except oil sight-glass tunnel not mentioned, nor petrol/oil drains.  Only component number that is given:
..6991........-...............Tyre inflator clip.  (Forgot to illustrate, just one, front LH side of petrol tank.  Other on frame tube?)
6993.........DW/CW25..Silencer (shared with CW), 09Aug24

There is not a large span in the surviving numbers attributed to the DW.  The lowest is 6880 and the highest 6993, a difference of only 113 of which 26 are explicitly known and listed here (excluding recycled parts.)  Certainly there may be higher and lower part numbers now lost, and one can see additional specialized parts would be required.  But compared to existing parts list for models like the EW or S6 that span some 2500 part numbers, it suggests the DW was mainly comprised of a limited number of new or altered components rather than an entirely new machine.  That is assuming if development was ever completed and all the components assigned numbers.  

That which survives show the DW was being drawn up from July through September of 1924, which means development was already in hand by then as proper working drawings seemed to trail actual work.  Documenting what was done appears to be the method employed.  It looks as if the EW started development at the beginning of 1925 if not a little before.  There might still be some records about that would put a finer date on the matter.  Patents attributable to the EW start being applied for by Douglas Motors Ltd. and Cyril George Pullin in February of 1925.  Early drawings for the EW date around July of 1925. Early production models or prototypes (not sure which) were available for loan in September and used in the Kickham trial, and on display at the Olympia show of the same month.  

The point being obliquely approached is, was there any significant overlap between the DW and EW design programs; was the DW killed in favor of the EW?  So far it really does look as if the DW was stopped first, and several months later work on the EW commenced.  But how far in advance was the idea of a completely new model conceived?  Was the DW cancelled on the promise of a coming improved successor?  That is much harder to judge.  The spotty drawing record shows once the DW was cancelled work seemed to switch over immediately to the CW25, with c7179 and 7206 being some of the few surviving examples dated to Oct/Nov of 1924.  A rim for optional balloon tires follows a bit later in March of 1925.  The CW would hold the fort till the EW arrived.  Also at the same time drawings for the OB25 were being made.  Some were revisions of existing drawings, and hence numbers lower than the DW.  Others are new parts with numbers between the DW and EW, for example 7182 (October ‘24) and 7535 (April ‘25.)  The lowest number found unique to EW in the Spares list is 7559.  

According to a notice in “Motor Cycling” of November 12th, 1924, S.L. Bailey had ceased acting as General Manager just a few days before the Olympia show in September though he did not sail for Australia till mid January, 1925.  This more than anything probably indicates when (and why) the DW project came to a halt.  That is not to say the DW lack of potential by then was becoming obvious and likelihood of a viable outcome nil; sufficient reason in itself for pulling the plug.  But it is a probably more than a coincidence that it corresponded with the departure of the General Manager and Works chief designer, whether he personally worked on it or not.  

In “The Best Twin” it is related Pullin was to take up duties of General Manager before the end of that year, exactly when I am not sure but it would have taken him some time to get settled in and down to business working on a new design.  Certainly he was capable of having his own ideas as to a new model (as we know) so why would he want to finish someone else’s project?  Interestingly at the same time Pullin started, Douglas Motors Ltd. switched to a new and more professional looking title block for their drawings.  

In hindsight, it is fortunate the DW was canceled.  Despite the early teething problems of the EW, it was far better than the DW ever would have been.  The DW was an attempt to breathe more life into the long past its ‘sell by’ date 2-3/4hp.  It would take more than a stylish new petrol tank and a new gearbox to reincarnate the old 2-3/4hp.  And speaking of the gearbox, what a waste on the DW.  Unless they had some undisclosed method of tripling the power of the 2-3/4hp engine, and more importantly keeping it together under the stress, the ‘box was major overkill.  The rubbish tip got the DW, and we got the EW.  I think we got the better machine.  

But one is curious, did they make a prototype?  Has anyone seen a photo of a DW, or any of the unique parts still kicking about?  Perhaps an EW petrol tank, yet no gear shift slot?  A set of 2-3/4hp crankcases, but yet slightly different?  Or a very odd frame?  Perhaps turned into a saw-bench as folklore dictates the fate of surplus 2-3/4hp skeletons?  Perhaps Bailey was instructed to take it with him to Australia to be disposed of as far from the factory as possible.  Who knows, maybe it is still down there.  Owners of CW25 models may take pride in that they have a small piece of surviving DW, the cast aluminum silencer that was to be shared between the CW/DW.  

© 2004, Douglas Kephart, Glen Mills, PA, USA

Offline Doug

  • Global Moderator
  • ****
  • Join Date: Mar 2004
  • Posts: 3464
  • Location: Pennsylvania, USA
Re: Article: The Missing Link, Virtual DW
« Reply #1 on: 09 Jul 2014 at 14:42 »
The Missing Link, Virtual DW, Part 2

There are two type of trade protection for a manufacture’s articles. One is a Patent and the other is a Registered Design. Registered Designs enabled a manufacturer to protect the shape or aspect of a design that might otherwise not have any new or novel construction or application. An example might be a pattern of lace or wallpaper having its design registered, though lace or wallpaper are not novel, nor the method of manufacturing new. This required a sample or a picture being deposited with the Board of Trade. Through the teens and early thirties Douglas registered a number of their designs to protect them from being copied. But in the thirties Registered Designs fell from favor as they were hard to enforce and so did not offer great value.

While researching Douglas’ Registered Designs I came across the enclosed photograph of a frame. The registered design aspect was solely limited the loop of the single down tube frame from the headstock to the bottom of the seat tube. (Subsequently used on the EW.) The frame did not quite look like any other Douglas frame that I knew, then I realized that it had the attributes that the DW model frame would have had.



The frame is fully finished with enamel and plated parts. The rear brake mechanism and pedal is in place, as well as the foot board brackets. In the original photograph it can be seen that the headstock transfer is applied, though it has been crudely and incompletely re-touched out of the picture.

This, along with some surviving drawings of other components, strongly argues that at least one complete prototype machine was made. The frame was dismantled to be photographed, or more likely photographed during the process of finishing and reassembly. Combined with the components modeled from surviving drawings (see part 1, NCR Mar/Apr 04) we now have a little bit clearer idea of what the complete machine may have looked like. Given the strong possibility a prototype was made, then somewhere out there, there may be a photograph of the elusive DW. Does it look familiar to anyone?





-Doug
© 2014, Douglas Kephart, Glen Mills, PA, USA

 

motorcycle