Beyond The Sprues

Modelling => Completed GBs => Group and Themed Builds => Informal Lockdown/COVID-19 GB => Topic started by: ChernayaAkula on April 27, 2020, 12:56:00 PM

Title: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: ChernayaAkula on April 27, 2020, 12:56:00 PM
Inspired by apophenia’s wonderful profile and back story (HERE (http://beyondthesprues.com/Forum/index.php?topic=9109.msg169225#msg169225)), I decided to have a go at it.

This is my base kit. Got it at 50% off. Which means it’s now only slightly more expensive than a comparable Zvezda or Revell kit.
Dragon’s kit isn’t the best moulded kit out there. I had to sand off flash on every single part. Slide moulds are cool, but when they’re improperly used, they mean more work instead of less.
(https://live.staticflickr.com/65535/49824686587_9d57949164_o.jpg) (https://flic.kr/p/2iUQxst)
ChernayaAkula_Churchill_17pdr_01 (https://flic.kr/p/2iUQxst) by Motschke (https://www.flickr.com/photos/151156765@N03/), on Flickr

17pdr barrel by RB Models
(https://live.staticflickr.com/65535/49824363906_d628d44cd1_o.jpg) (https://flic.kr/p/2iUNTx1)
ChernayaAkula_Churchill_17pdr_02 (https://flic.kr/p/2iUNTx1) by Motschke (https://www.flickr.com/photos/151156765@N03/), on Flickr

To quote Bob Ross: “Here’s your bravery test!”  First cuts. Lots of them. The running gear has one less road wheel.  Therefore, the running gear, hull and sponsons had to be shortened by about one road wheel bogie length. Cuts are pretty rough. Used the trusty JLC razor saw, but I somehow always managed to get them lopsided. I don’t want to blame the tool (bad workmen and so on…), but I think the way the razor saw attaches to the handle imparts some twist on the blade if you apply any pressure. More cuts by a disc saw in the Proxxon. Shoulda used my trusty coping saw instead. In the end, the cuts weren’t too bad. Thanks to some Tamiya angled plastic profile, it all lined up rather nicely.
The running gear is made from two parts per side. To keep some structural integrity, I cut out single bogie bits at different locations. Though this be madness, yet there is method in't.
(https://live.staticflickr.com/65535/49824363886_3e579610af_o.jpg) (https://flic.kr/p/2iUNTwE)
ChernayaAkula_Churchill_17pdr_03 (https://flic.kr/p/2iUNTwE) by Motschke (https://www.flickr.com/photos/151156765@N03/), on Flickr


To lower the idlers, I simply cut of the extreme tips of the sides in order to swap them  and thus turn them around. The parts attached here to the right side are actually from the left side. I figured that would be the easiest way to lower the idler.
(https://live.staticflickr.com/65535/49823833813_86f9bb743f_o.jpg) (https://flic.kr/p/2iULaXt)
ChernayaAkula_Churchill_17pdr_04 (https://flic.kr/p/2iULaXt) by Motschke (https://www.flickr.com/photos/151156765@N03/), on Flickr

The white styrene bits on the left (below the idler) are there to reinforce the join where the cut-off tips have been reattached. Since this kit uses rubber band tracks – Dragon’s DS track are still rubber bands! -, I figured the idler needs all the support it can get. The white styrene bit on the right will hold another styrene rod that will attach directly to the idler.
(https://live.staticflickr.com/65535/49824686492_954477e3e2_o.jpg) (https://flic.kr/p/2iUQxqQ)
ChernayaAkula_Churchill_17pdr_05 (https://flic.kr/p/2iUQxqQ) by Motschke (https://www.flickr.com/photos/151156765@N03/), on Flickr

Second rod in place. This will – I hope! – adequately keep stress imparted by the rubber band tracks off the idler axes.
(https://live.staticflickr.com/65535/49824363801_cda7d3fbca_o.jpg) (https://flic.kr/p/2iUNTvc)
ChernayaAkula_Churchill_17pdr_06 (https://flic.kr/p/2iUNTvc) by Motschke (https://www.flickr.com/photos/151156765@N03/), on Flickr

Dragon’s track don’t fit the idler teeth too well (same goes for the drive sprockets). Any invisible teeth will have to go.
(https://live.staticflickr.com/65535/49823833783_fdf87c1f8e_o.jpg) (https://flic.kr/p/2iULaWX)
ChernayaAkula_Churchill_17pdr_07 (https://flic.kr/p/2iULaWX) by Motschke (https://www.flickr.com/photos/151156765@N03/), on Flickr

Pulling teeth. No anesthesia. Looks much better, though. The track in the foreground – tensioned by lots of force exerted by a file – looks… okay-ish. The bit between the idler wheel and the top of the sponson still bows upwards. Unrealistic! It should sag ever so slightly. Damn rubber band!
The track in the background isn’t tensioned. I hope Dragon’s DS tracks do actually glue with plastic glue and bond with the plastic of the sponsons. The way the length of track between the idler wheel and the top of the sponsons looks is critical to a realistic look.
I hate rubber band tracks.  :icon_twisted:
You can also see where the cuts on the sponson sides join. The upper part will be hidden by the exhausts. The lower will need a bit of putty. Even the tow cables line up rather well.
(https://live.staticflickr.com/65535/49824363771_a7e32e9b4a_o.jpg) (https://flic.kr/p/2iUNTuF)
ChernayaAkula_Churchill_17pdr_08 (https://flic.kr/p/2iUNTuF) by Motschke (https://www.flickr.com/photos/151156765@N03/), on Flickr

So much for now. Hope to get cracking on the casemate tomorrow.
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: Buzzbomb on April 27, 2020, 02:23:57 PM
Wow lots of work happening.
I have to agree those tracks are awful. Any Airfix Churchill tracks available ?
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: Robomog on April 27, 2020, 03:09:12 PM
You've got off to a good start there, some clever plastic surgery, your right to want to get the track to lie properly it's an important part of the look of the machine.

Mog
>^-.-^<
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: ChernayaAkula on April 27, 2020, 09:36:13 PM
Thanks, guys!  :smiley:

Would the Airfix Churchill tracks have heen any better? Aren't they also vinyl*? I did consider the Esci/Italeri Churchill for a moment, but couldn't find one. That one has link and length tracks.
Also considered the Tamiya 1/48 kit. Also link and length. Had second thoughts about link and length as the track geometry is changed thanks to the dropped idler. Probably unfounded, thinking about it now.
And any available AFV Club 1/35 Churchills were too expensive for my taste. :P
Dragon's DS tracks seemed to be the best (well, least worst  :P) available possibility. If they do glue to themselves/the sponsons as advertised, I should be good.

* Technically not actually vinyl. At least the Dragon DS tracks aren't.
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: Frank3k on April 27, 2020, 11:15:58 PM
That’s some serious surgery! Aren’t those Dragon’s DS tracks? If they are, you can use regular plastic segment to glue them.
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: ChernayaAkula on April 28, 2020, 12:39:01 AM
Thanks and yes, DS tracks. Will any plastic cement work or are some better suited? Got Tamiya Extra Thin Quick-Setting, Tamiya Extra Thin (of the regular speed variety) and Revell Contacta Professional on the desk.
Actually used Revell Contacta for the first time in donkey's years yesterday. Helped with the bogies. Couldn't reach some areas with Tamiya Extra Thin Quick-Setting, which has been my go-to cement for quite some time now.

Have tried Revell and Tamiya on some cut-offs (owing to the shortened running gear, the tracks would now too long) yesterday. Will have to see how well they've bonded.
Will also try to glue the cut-offs to some Dragon sprues and see if that forms a bond.
If push comes to shove, I'll just use some 2-part epoxy.... :icon_ninja:
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: Jeffry Fontaine on April 28, 2020, 02:21:30 AM
When it comes down to needing to use "Two-Part Epoxy" you are getting serious.  :smiley:
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: Buzzbomb on April 28, 2020, 07:01:59 AM
If push comes to shove, I'll just use some 2-part epoxy.... :icon_ninja:

That's the spirit ! My go to as well when things are not staying where they should be.

I mentioned Airfix tracks, because I feel they are softer plastic/rubber and might conform better, but then not used that scale for many a year so the compound may have changed.
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: ChernayaAkula on April 28, 2020, 07:58:06 AM
My last experience with Airfix tracks was 20 years or so ago. WWI tank. I think they did conform, but only because I tied them to the sponsons with wire.  C:-)
I have a Tamiya 1/35 Churchill. The tracks on that one simply popped off at some point. Tore between two links on the idler. Had been sitting there for years and then one day there's an audible (!) pop and that was that. They used to be flexible but they're fairly stiff now.
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: Robomog on April 28, 2020, 09:11:59 AM
Long time since I've built AVF's.

As far as I remember Airfix tracks were a silver stretchy vinyl which needed the ends heat sealed together using a hot knife.   But I found a, couple of small staples were more effective to join the tracks and then hid the join behind  the dust guards

I also found that after a couple of years some of the tracks had a strange reaction  with the polystyrene plastic and melted to it !

This is 1970 something they might of changed the formula  of the vinyl tracks now and there are probably better adhesives available now than then

Mog
>^-.-^<
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: Frank3k on April 28, 2020, 09:44:37 AM
The DS tracks should glue/melt with any of the styrene/ABS cements listed.

From the Wikipedia entry (https://en.wikipedia.org/wiki/Dragon_Models_Limited):
Quote
One-Piece DS Tracks

A few of Dragon's newer kits, such as its Sherman M4A2 kit, include one-piece tracks made from 'Dragon Styrene 100' (DS), a plastic developed by Dragon's own Research and Development team. A cross breed of polystyrene and vinyl, DS is an attempt to combine the advantages of the two materials. Delicate details can be reproduced with DS using under-cut molding, reducing the number of small parts. The Tiger I hollow guide horns, for example, can be replicated on DS using slide-mold technology.[4] These tracks can also be joined with normal plastic cement.

Some recent DS tracks seem to have an issue of being too long or too loose.[5] The tracks may also come stretched due to packaging limitation, but the issue can be resolved by soaking the tracks in hot water.[6]

Note that people have had issues with the DS plastic (disintegrating in their package), but yours seem OK.
Title: Re: 1/72 Self-Propelled OQF 17-pounder, Churchill Mk.XX – Dragon + RB Model
Post by: apophenia on May 01, 2020, 03:29:51 AM
That’s some serious surgery! ...

Indeed ... and its looking dead impressive  :smiley:  Can't wait to see how this goes  :D

Attached for ref.