2 3/3 flywheel sprocket spacer

[Dave@NZ]

Hi
We are currently about to install the flywheel and have noticed there is no spacer between the sprocket and flywheel, at disassembly there was no spacer fitted and the spare flywheel I have does not have one.

The interesting thing is in the Douglas parts manual item, 571d distance collar for sprocket 1/2 -3/8 but it is not listed for the
5/8-1/4 sprocket. Just to clarify we are using 1/2 -3/8 sprocket.

I am surmising width would be 1/2 the difference between 3/8 and 1/4?

Is it meant to have one and does anyone have the width dimension if so.
Many thanks
Dave.

[Hutch]

Hi Dave,
I think the important thing is that the primary chain line is straight. Due to manufacturing tolerances,  wear on the tapers for the chain wheels where they go on the shafts, bent frames etc.etc. the flywheel sprocket and gearbox sprocket won't necessarily be in perfect alignment. I would do a trial fit up of the gearbox and engine in the frame and check the alignment. If a spacer is needed and how thick it should be should be easy to work out and then just make one of the correct dimension on a lathe.

I seem to remember the 2 3/4 handbook having something about different width spacers being available from the factory. I don't have that handy right now, but will look it up when I get a chance.

Cheers

Ian

[Dave@NZ]

Hi Ian,
 Thanks for the info we are going to mount up the flywheel hopefully within the week it will probably be 2 years before the gearbox engine and frame are assembled due work commitment of the owner.
I am getting the engine reconditions to install the flywheel as final part of there taper repair process and that way it will be under there warrenty.

I know what you mean of making sure sprockets are in alignment and that will be checked at installation.

If it is meant to have a spacer and we install it and found at installation was out of alignment it might be the case of loosening the sprocket and filing the spacer in half to remove it then retighten the sprocket all with out disturbing the flywheel on the taper.

We are trying to determine if one should be in there at all I have read the manual I have and found no mention
of it but will keep looking.
Thanks
Dave.


 

[Alan Cun]

I have just about finished assembling a 26 TS for a friend being for a quantity of vintage car parts. When I mounted the flywheel I realized the spacer was missing so used a large washer about 3/16 thick and turned it down to fit.

I have mentioned before that I like to fit an endless C78 belt which is very easy to fit if you just unbolt the rear stay carrier and stand. These belts without a joiner can take good tension and non slip in the wet.

This time however the half link needed in the primary chain would not work. Too lose chain. I could not work out how I could move the box forward and fit a half link. But I shortened the chain and fitted the half link. Then adjusted the slack and tightened the box and forced on the belt on. Very tight. Problem solved belt riding high on rear pulley I picked up a hammer and with the aid of a piece of wood modified the width of the pulley by driving the belt further into the pulley. Problem solved

regards Alan

[Dave@NZ]

Thank you Alan and Ian for the pointers, what I have decided to do is have two spacers made each approx 1mm thick and loosely install the sprocket and then fully install the flywheel.

When the engine and gearbox are installed in the frame we can check the sprocket alignment as out lined in your suggestions and if necessary with the flywheel still installed remove one or both spacers by using a mini hacksaw or the like.

If it needs more than two spacers time to remove the flywheel.
Thanks,
Dave.

[Hutch]

Hi Dave and Alan,
My memory was slightly awry (not unusual these days!), but on page 88 of the 1925 2 3/4 Handbook it says;
"Distance pieces may be obtained to vary the chain lines of 1915 and 1916 models to suit earlier models."

As the 1925 handbook is made up of bit and pieces from previous years handbooks and this is also a quote from the 1916 Handbook (pg 73), then I assumed that it meant distance pieces are available for all models after 1915 to alter the chain lines to that of the previous models ? Then this got me thinking, because I haven't seen any differences in the dimensions of the 2 speed gearboxes from before or after 1915. As the 3 speed was introduced in 1915 then what I think they may be referring to is if you were to put a 2 speed into a 3 speed model then you would have to change the chain line?...I hope I haven't confused you as I have managed to confuse myself! :-) !!

I understand your dilemma and guess that you will have to put the spacer in and then see later if it was the correct thickness. I don't know the dimension  of a "standard" spacer as I don't have one. A forum member may be able to help out with that info.?

All I could find was this drawing from the 1914 handbook (that would have only had a 2 speed box). Alan's 3/16" is probably not far off the mark. Note that the part numbers are different as Douglas changed them after 1914.

If I get a chance I'll dig out a 2sp and 3sp gearbox and measure the distance from the centre of the mounting studs to the primary chain wheel. I'll compare this to the dimension given for the chain line in the handbook. This may point to what spacers are needed, but it appears at this stage that one is needed for a 2 speed 1915?

Ian

[Hutch]

Dave,
I have just had a look at the 1914 and 1916 parts list and there appears to be no part listed for the  "Distance Collar for Sprocket". The first reference I can find for it is in the 1918/19 2 3/4 H.P Spares list errata as part 571D. But it is obviously shown in the 1914 engine drawing with no part number attached - maybe an oversight by the factory or they were selectively fitted during machine assembly early on?.

-Ian

[Dave@NZ]

Thanks for your help and input it is not well documented about the spacer may be as and when required type of thing when assembling on the production line.
I am quite confident to make two spacers and install them now is the best decision, time will tell if it works out as planned.
Thanks,
Dave.