A few photos from Russ' findings on the 8" Howitzer:

Slight Error Found in Roden - Holt Tractor Instruction Sheet - Step 14:
Cone clutch plate (Part 17B) needs be reversed 180 degrees to face the other way in order to be correct.

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Main Clutch (Cone design) for Holt 75 Tractor Shown Below:





Photo and Color Drawing; authors unknown - used here for discussion purposes ONLY.

I want to model the cone clutch to better fill in that particular portion of the Holt driveline. I have already opened up the inspection panel on top of that tapered sheet metal housing for a little more light and visibility in that area. I'm thinking perhaps a properly sized model railroad wheel would serve as the male portion of the clutch.

Thanks Michael for finding the "cone clutch" drawings. So I guess I was right after all when I flipped part 17B around in my build (which makes sense from looking at the parts). But I had looked at another photo which seemed to show the hollow side facing the flywheel. I'm wondering if part 17B should just be a hollow "ring" with a wheel inside to represent the clutch as Michael shows in the diagram.
VR, Russ

I too went with reversing the clutch plate on the kit build even before I found the research - just simply because the parts fit better that way and did not when facing the other way.

I agree with you Russ it might also be correct to have an open drum behind the flywheel instead of the cone clutch.

Personally I think the open drum wheel in the photo below is NOT part of any kind of clutch. I think the engine shown here was used as a stationary industrial engine rather than a vehicle mount. I suspect it was used to drive an overhead belt arrangement rather than a fixed shaft.

p.s. Note that in the O scale model photo I posted earlier it shows the cone clutch without the sheet metal protective cover.


Photo credit unknown - used here for discussion purposes ONLY

Interesting video of running Holt 4-cyl. engine.

Note open flywheel and brass/bronze oil lubricator.

https://www.thvideos.net/video/CCSsOZdJiCs/1917-holt-engine.html





In this case the belt driven accessory is a circulation water pump to cool the engine.

Michael-- great research photos! Thanks for posting these, they will greatly help anyone building the kit.
VR, Russ

I opened up the clutch inspection plate just to add a little bit more detail. Still have not begun work on the cone clutch itself - looking now for a properly sized tapered cone for that construction.

(I am thinking a wheel off a properly sized model railroad freight car might do nicely for the clutch cone - now I only have to decide which scale.)

Russ, (Kevlar06) any chance you have the manual on the Holt tractor as well ?*?*?*?*?*?*?*?


Anybody ????????

Michael,
The closest I've come to a manual for this tractor is the link I gave in a previous post at CCModels.com, which is a maintenance brochure:

https://ccmodels.com/wp-content/uploads/2014/06/CCM_Brochure_for_Holt75_Howitzer.pdf

I've looked all over the 'net for a manual but haven't been able to find one. There's even an antique tractor "museum" of sorts in a town about 40 miles from where I live, but all they had going back that far was a 1930 Fordson manual. The guy that owns the museum told me he'd keep an eye out for one, but so far nothing. In the tractor world, these old "steering wheel Holts" are really considered dinosaurs I guess, and very few still exist due to their complicated operation and maintenance. Let me know if you find one.
VR, Russ

A few progress shots on my Holt:

I thought I would add some reinforcement triangles to that very delicate front wheel assembly.
If carefully assembled the front wheel can be made to roll as well as to steer.





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Whats the general opinion on my using a diamond pattern screening over the radiator front? It will look really good if painted green in contrast to the black radiator! I happen to have the diamond screening and it would certainly show up more but I admit from the outset - it is not correct.

Slow progress on the Holt these days.

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Metal screening cut and painted.

Please Note: - To my fellow modelers - Please know that while the above screen treatment may be more visible and/or look better on the model, This treatment IS INCORRECT as to the prototype! The actual vehicle employed a straight horizontal, square web radiator screen. I post this notice as a warning to not always follow one modeler just because he or she chooses to jump off a cliff.

Michael, I think the diamond pattern looks great and very distinctive, and a great alternative. On another note, a driver for the Holt may be on the way soon. The tractor seat is actually sprung, and the forecasted driver will come with a proper seat. More later.
VR, Russ

Great news Russ! I was considering perhaps using the Liberty Truck driver but repositioned for the Holt.

Michael, yes, I've seen some test shots and requested if they can be shared here, so be patient. Evidently, the seat support was a sprung affair, and as such, the parts in the Roden kit represent the seat in it's "unmanned" position. Therefore this new figure will come with a new seat altogether so the driver's feet can reach the pedals appropriately. So it'll save a lot of would-be conversion work on other figures. Not sure when it'll be available.
VR, Russ

For those interested, Paul at Model Cellar has two WWI Artillery figures on the way in quite relaxed poses, along with a Holt driver, complete with a new seat for the tractor. The seat is necessary, as the original supporting bar was sprung, and would be lower than the kit seat with the weight of a driver, allowing the driver's feet to reach the pedals. The three figures are sculpted by Mike Good, and look great. These figures should be available in September. Paul informs me the figures will be differentiated for US, Australian and British crew by their headgear-- the Artillery figures are posed in a "work" uniform, without tunics and in collarless shirts and suspenders, making them ideal for an informal "rest break" while emplacing the Howitzer or working on the tractor. The seated driver is also in a similar "work" uniform. These figures will be a great addition to the kit, along with Model Cellar's wheel treads for the Howitzer.

Also, Heres a link to Charlie Duckworth's Holt Tractor and 8" Howitzer over on Landships:
https://landships.activeboard.com/t65702593/holt-tractor-and-howitzer/

VR, Russ

Russ,

Thanks for mentioning the Holt driver and Artillery figs.
I can't seem to upload pics. But, I sent Charlie an advanced copy of the driver (with our new seat stand). Here is his finished product so that you can see what it looks like:

https://www.track-link.com/forums/modelling_kits/20594

And here is a link to the artillery figures which we previewed back in May at MFCA:

https://www.planetfigure.com/threads/w-w-i-british-australian-artillery-crew-1-35-model-cellar.136745/

Box art should be finished by end of August.

regards,
Paul

Folks-- Paul just sent me an email with a link to the driver figure done by Charlie Duckworth over on Track-Links (same one as above, but I thought I'd post it twice for emphasis!:)
https://www.track-link.com/forums/modelling_kits/20594

It's well worth a look. Now before you guys jump all over me and tell me it's not an "American" figure-- Paul (Model Cellar) will be offering it with the three styles of headgear, to distinguish it a bit more as Australian, British or US, since he's depicted in a working uniform.
VR, Russ

Excellent figure - well done pose - must have!

Fortunately have held off attaching the seat. Should be no problem posing it "under load".

Yes, me too, but I'll have to modify my built version-- but Paul tells me it's not too difficult to do, so I'm also looking forward to this new figure from Model Cellar. We can't get enough WWI figures! And this one promises to be exceptional for diorama purposes with the Tractor and the Howitzer combination.
VR, Russ