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WW1 Armour, Artillery, Vehicles, Ships => WW1 Armour, Artillery, Vehicles, dioramas, associated figures and Ships => Topic started by: Chris Johnson on June 13, 2020, 10:49:17 PM

Title: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on June 13, 2020, 10:49:17 PM
(https://i.imgur.com/YqSLUz9.jpg)

Following up on my inbox review of Roden's combination kit of their Holt 75 Tractor and 8-inch Howitzer and Limbers sometime ago, I thought I'd post a build log now that I've actually gotten around to building the kit. Right up front, I need to say that what looks good in the box, isn't necessarily the case once we start the actual construction. Bear in mind here that we have two separate kits in this box so problems associated with one won't necessarily apply to the other. Time will tell.

I've started construction with the Holt 75 tractor. My advice to anyone considering building it is to come well armed with files and sanding sticks. And patience. Lots of patience. The major problem seems to be rooted in substandard tooling which has resulted in a pronounced mold shift. There are thick and deep mold release lines on most parts that take considerable effort to remove, as illustrated in this ring that is part of the front wheel assembly. This is supposed to be a flat faced ring. Rod shaped parts can be somewhat oval in shape too, requiring some finessing.

(https://i.imgur.com/K7kEnnB.jpg)

I've done some research online together with discussing it with a couple of friends building the tractor kit, and they have experienced the same issues, so this isn't a one-off problem limited to my example. However, the saving grace here is that once you invest the elbow grease, everything fits together very well.

The major problem with the Holt 75 kit, and it's a big one, is with the corrugated roof. On the underside, we can see the centre stringer that is molded to the roof, and eveything is good, as the corrugation is quite well done.

(https://i.imgur.com/mPYHUgi.jpg)

The topside of the roof is a different matter though. In my inbox review, I completely missed the pronounced sink mark that extends from one end of it to the other. I must have been blind at the time. The problem is compounded in that it affects both the troughs and the ribs. If you look closely, you'll also see the extent of the mold shift on the tree runner.

(https://i.imgur.com/Dk23krK.jpg)

I employed sprue-goo, round files and sanding sticks to correct the issue, and it came out looking not too shabby.

(https://i.imgur.com/ckMIhN5.jpg)

Not too shabby until viewed from a different angle and lighting, where some sanding flat spotting was in evidence.

(https://i.imgur.com/vLh9Ccs.jpg)

I wasn't sure that I could completely eliminate this issue, so I decided to make a replacement roof. I used the repaired roof as my template, and employed 36 gauge pewter sheet and a rounded off wooden skewer stick as my embossing tool. Unlike lead foil, the pewter sheet is thick enough to hold the curved shape of the roof and the embossed pattern.

As one would expect, the embossing process transferred the flat spotting to the pewter sheet, but it was just a matter of sliding the new roof off centre a little bit and re-embossing that area again to remove the issue. All in all, I was pleased with the result, and being so much thinner than the plastic roof, it's more scale appropriate.

(https://i.imgur.com/9Xyi2Kg.jpg)

With the roof fixed, I decided that it would be worthwhile continuing on with the project.
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Radarman on June 13, 2020, 11:52:21 PM
Chris,
Thanks for sharing this technique. I had never heard of pewter sheet.
                                                                                   
                                                                                             Kevin
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: gedmundson on June 14, 2020, 02:20:03 AM
Chris - magnificent work on the roof. Your dedication to "making it right" is spot-on. And it's a most interesting project, too.
Cheers,
Gary
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on June 14, 2020, 07:00:03 AM
It's a handy material Kevin. Very pliable and heavier than lead sheet. Worth looking into.

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on June 14, 2020, 07:02:09 AM
Chris - magnificent work on the roof. Your dedication to "making it right" is spot-on. And it's a most interesting project, too.
Cheers,
Gary

I won't be surprised to see you add it to your project list Gary.

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Alexis on June 14, 2020, 10:23:10 AM
Now that looks really cool for a subject Chris , following with interest .


Terri
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on June 25, 2020, 01:33:09 AM
I read where at least one modeller had difficulties with the construction of the front wheel assembly, so I thought I'd get that out of the way next. As can be seen in the instructions, it's a bit of a complex assembly. The repeating theme here is that lots of cleanup was required for all of the parts.

(https://i.imgur.com/26TVSt8.jpg)

The wheel itself needed clamping to improve the joints between 9F, the spokes (11D x2) and the outer rim (7D) parts.

(https://i.imgur.com/iGVlgRK.jpg)

(https://i.imgur.com/4QSsdiT.jpg)

With a bit of patience, I found that it all went together quite well.

(https://i.imgur.com/oHum0Ls.jpg)

The chassis frames went together without issue, but the race for the front wheel assembly did require clamping.

(https://i.imgur.com/E5YjVYF.jpg)

I jumped ahead here and built the final drive housing and the radiator tank. The latter sits in a box together with the engine. The tank was a bit of a disaster as its detail was quite soft and all of the rivet detail on its top was lost when cleaning up the joint. I replaced that detail with Meng rivets. The front wheel assembly was a good tight fit inside its race and the rails incorporated with the final drive housing mated well with the chassis frame and radiator/engine box.

(https://i.imgur.com/Olyx7io.jpg)

Next in line were the tracks. These involved considerable cleanup as thick flash was commonplace, and there are three ejector rod depressions on the inner face of each link. I didn't bother cleaning up the centre ones as they're hidden from sight. The links click together but they're very loose. That being the case, after finishing the suspension, I elected to glue the track runs in place. There were only two extra links, so my advice is to be careful when cleaning them up so as not to damage any. There aren't any aftermarket tracks available, so be very careful.

(https://i.imgur.com/ZgPugB5.jpg)

(https://i.imgur.com/QP73MqY.jpg)

The track runs fit well, and I was pleased with the final result.

(https://i.imgur.com/bd93oW6.jpg)

The underside of the chassis is quite busy, and everything fit well after extensive cleanup.
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Alexis on June 25, 2020, 09:53:01 AM
I'm really impressed with the level of detail this kit has  :)


Terri
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on June 25, 2020, 10:05:55 AM
I'm really impressed with the level of detail this kit has  :)


Terri

It's a strange kit Terri. Some detail is quite good, while some is soft. Everything fits well though, after the application of considerable elbow grease that is.

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Dave Brewer on June 25, 2020, 10:13:55 AM
This will be very valuable to anyone taking on this kit Chris,which is coming along very nicely despite the surprising quality issues.Can't help wondering how the roof would look under a coat of paint,but the pewter one looks fantastic,I've not come across this material before.
Cheers,
Dave.
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: gedmundson on June 26, 2020, 06:48:07 AM
Great to see the pics and follow you build here, Chris. You are right - I'm very attracted to this subject and will have to "add to cart" I'm sure at some point. Your model is quite inspirational.
Cheers,
Gary
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Borsos on June 26, 2020, 07:24:23 AM
Thatís a great build and a joy to follow. I own both, the Roden and the Resicast kit, so I am watching evťry step you do here.
Andreas
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on June 26, 2020, 08:42:30 AM
This will be very valuable to anyone taking on this kit Chris,which is coming along very nicely despite the surprising quality issues.Can't help wondering how the roof would look under a coat of paint,but the pewter one looks fantastic,I've not come across this material before.
Cheers,
Dave.

This is my first experience with lead free sheet pewter Dave, and I plan on using it again as I found it easy to work with. The kit quality isn't up to current standards in the industry but aside from the resin kit from Resicast, it's the only game in town. I think it's superior to the Resicast model from what I've seen.

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on June 26, 2020, 08:46:06 AM
Great to see the pics and follow you build here, Chris. You are right - I'm very attracted to this subject and will have to "add to cart" I'm sure at some point. Your model is quite inspirational.
Cheers,
Gary

The model will basically be OOB with just a couple of modest improvements Gary, so hopefully this build log will give other modellers a good idea of what to expect. I'll leave the really fancy improvements to you!

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on June 26, 2020, 08:48:13 AM
Thatís a great build and a joy to follow. I own both, the Roden and the Resicast kit, so I am watching evťry step you do here.
Andreas

Chime in anytime Andreas with a comparison to what you see in the Resicast kit.

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on July 07, 2020, 12:48:35 AM
The engine surprised me a bit with it's detail. I was quite impressed with it built up, straight out of the box. I had considered adding plugs and wires but those are included and after the engine is fully constructed, hardly visible, so I didn't see the point in replacing it with something more detailed. The engine fits perfectly with the radiator tank in their box.

(https://i.imgur.com/tZiMpPR.jpg)

(https://i.imgur.com/ShoVDsC.jpg)

(https://i.imgur.com/YSQyxXv.jpg)

(https://i.imgur.com/QdvNGkI.jpg)

With the engine test fitted in place, I decided to ensure that the replacement roof would line up with it. As the centre roof support beam is molded onto the underside of the kit supplied roof, it required adding one from strip stock to the roof frame.

(https://i.imgur.com/5k8JaOq.jpg)

(https://i.imgur.com/J8IkFZS.jpg)

With the frame in place, I added the exhaust stack to the engine and checked to make sure it lined up with its hole in the new roof. It did!

(https://i.imgur.com/GTN6GqA.jpg)

(https://i.imgur.com/kWvFi7R.jpg)

(https://i.imgur.com/gzTgErw.jpg)

(https://i.imgur.com/Tg3ZDrl.jpg)

Images showing rolled or scrunched up curtains on the four sides of the roof frame are commonly seen, so I decided to add that detail. I used Tamiya Quick Type epoxy putty and straps made from strips of masking tape.

NOTE: Bear in mind here that the roof structure and radiator are only dry fitted in place in these images so they aren't perfectly level.

(https://i.imgur.com/FL54Fh0.jpg)

The figure is from the Stalingrad line, painted with oils and Vallejo acyrlics. At this juncture, I hadn't decided on its final position.

(https://i.imgur.com/XoZ9f2l.jpg)

Thanks for looking in!

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: kkarlsen on July 07, 2020, 02:20:24 AM
Great show! I love it..

Kent
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: RAGIII on July 07, 2020, 02:33:31 AM
I have just gone through your posts and am as impressed as ever with your Modeling skills! You are turning this one into a Masterpiece! The roof is Most impressive as is the figure !
RAGIII
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on July 09, 2020, 12:18:05 AM
Great show! I love it..

Kent

That's good to hear Kent. You never know how these build logs might be received on an aviation site.

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on July 09, 2020, 12:18:55 AM
I have just gone through your posts and am as impressed as ever with your Modeling skills! You are turning this one into a Masterpiece! The roof is Most impressive as is the figure !
RAGIII

Thanks RAGIII!

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: FokkerFodder on July 09, 2020, 07:50:44 AM
Iím enjoying it to! This has been on my wishlist for ages and your build is providing lots of great tips! Cheers Matt
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on July 09, 2020, 09:07:33 AM
Iím enjoying it to! This has been on my wishlist for ages and your build is providing lots of great tips! Cheers Matt

Glad to hear it might be helpful Matt. Just be prepared for a lot of cleanup.

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Alexis on July 09, 2020, 10:32:05 AM
Excellent progress Chris ,

I like the detail in the kit , that engine is really nice and the curtins are a nice touch . :)



Terri
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on July 09, 2020, 10:53:57 AM
Excellent progress Chris ,

I like the detail in the kit , that engine is really nice and the curtins are a nice touch . :)



Terri

Thanks Terri!

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Edo on July 10, 2020, 04:17:26 PM
I donít know how I missed this thread before, but iím glad i discovered it now as it is a great build log and and a source of inspiration!
i canít wait to see this unfold!
ciao
edo
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on July 10, 2020, 08:13:07 PM
I donít know how I missed this thread before, but iím glad i discovered it now as it is a great build log and and a source of inspiration!
i canít wait to see this unfold!
ciao
edo

Thanks Edo!

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: ModelCellar on July 25, 2020, 07:12:24 AM
Chris.

Nice work !  ...looks GREAT !!  Now I just want to see it painted and weathered =).

Paul
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on July 25, 2020, 08:32:25 AM
Chris.

Nice work !  ...looks GREAT !!  Now I just want to see it painted and weathered =).

Paul

Thanks for looking in!

Cheers,

Chris
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: bobs_buckles on July 25, 2020, 08:40:58 AM
Superb!

 :o
vB
Title: Re: Holt 75 Tactor and 8-inch Howitzer Build Log
Post by: Chris Johnson on July 25, 2020, 09:12:08 PM
Superb!

 :o
vB

Thanks Bob!

Cheers,

Chris