Alchin traction engine

[joseph tatlerParticipant @josephtatler55359]

Hi

Can anyone help!!!!!

built the jig for the Hind wheels but am at a loss as to see how the spacers are used in the jig.

The book does not seem to be very useful on this.

Any help would be gratefully received,

joe

[joseph tatlerParticipant @josephtatler55359]

[JasonBModerator @jasonb]

The spacers fit onto the central post to raise the hub as required to give the correct offsets from the side of the rim. If you look at the cross section through the rear wheels on page 79 you can see the offset hub so arrange spacers as required for the first side and then alter spacing when you turn the wheel over to spoke the other side.

Edited By JasonB on 14/04/2023 09:13:29

[Clive Brown 1Participant @clivebrown1]

Hi Joseph,

Presumably your spacers are the two thick washers, 9/16" and 7/32". The 2 rear wheels of the Allchin are slightly different from each other. The hubs are at different horizontal offsets to their respective rims. The appropriate spacer is put on the central spigot of the jig to support the hub and so ensure the correct offset for each wheel.

HTH.

edit beaten by Jason

Edited By Clive Brown 1 on 14/04/2023 09:15:57

[joseph tatlerParticipant @josephtatler55359]

all

thanks for the clarification it was really good.

one more query ,please, i just read again the text and it says 17/32" for the smaller spacer i made mine 7/32" as the print on the diagram is a bit faint.

Can anyone confirm that it should be 17 and not 7? i dont want to make a B^^^S of the wheel.

thanks everyone for the help.

joe

[JasonBModerator @jasonb]

Best to work it out from the wheel drawings they give offset to outer face of hub so add that to the thickness of the inner and outer plates and then subtract how far the post flange is above the wheel rim edge on the jig.

[Clive Brown 1Participant @clivebrown1]

As Jason says, measure up on your jigged assembly against the wheel drawings before commiting to all that riveting. The rim / hub offsets are important. However, the thickness of the spacer is shown as 7/32" in ME no. 3489 for 17 May 1974 and I don't remember any dimensional problem when I made mine.

[joseph tatlerParticipant @josephtatler55359]

Dear all

tahnks for the time to help, but started to put the spkes in asper stated in the book.

Made the jig ensured the flange of the centre was 9/32" above the rim and proceeded to set the spokes wih the large flange on the centre as per book.

set spokes out no problem rivet and bolted.

turned over set the spacer in place but there is a gap of around 1/4" between the base of the wheel hub and the spacer.

The rims are perfectly flat on the baseboard of the jig,

Whats wrong any ideas

[JasonBModerator @jasonb]

Looks like its the strake ends that are meant to rest on the jig top surface not the side of the rim

[Clive Brown 1Participant @clivebrown1]

Agreed, the strake ends are used as the dimension datum in the jig shown in ME, a bit of a trap for the unwary IMHO.

Also, I'm afraid that I might have repeated an error in my earlier posts. The ME drawing definitely shows the spacing washers as 9/16" and 7/32", which I quoted. However, I've now read the text and that does refer to a spacing washer of 17/32", so maybe that is the correct dimension as the OP originally wondered.

However, the essential requirement is to locate the hub correctly in relation to the edge of the wheel-rim. The drawings show that for the RH wheel hub the spokes are 7/8" below the outer edge of the rim. For the LH wheel hub, the measurement is 29/32". (These dimensions might be difficult to read in the reduced size of the book). Note also, the 2 hubs are different widths. The jig and the spacing washers should match those dimensions.

HTH

Edited By Clive Brown 1 on 16/04/2023 15:56:40

[JasonBModerator @jasonb]

Though as the strakes are 3/64ths in from the rim's edge I would expect any packing to be ?/64"

[Clive Brown 1Participant @clivebrown1]

Heres a copy of the original drawing in case it's clearer than the book.

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