JMP Chevrolet G7107

[Alex]

On 11/5/2023 at 4:55 AM, thierry laurent said:

Actually they were made during the nineties from scratchbuilt masters. So, indeed, they were available far before the common availability of the internet. This reminds me the good old times of the rec.models.scale text-only forum when I got my first Internet access 30 years ago. At that time universities, labs, some civil services and very large corporations were the happy few users of the Internet!

Fond memories of those listserv days from back when I was in grad school (and had to log on to the campus mainframe to read them)!

[LSP_K2]

12 hours ago, LSP_Kevin said:

Speaking of making things fit, I think I've got the cab fit to the chassis sorted out:

 

 

I'm assuming that the ridge or lip along the lower edge of the cab on the right side shouldn't be there?

 

Kev

 

Yes, it should be, but the area at the bottom of the hood sides should be removed.

 

[LSP_Kevin]

16 minutes ago, LSP_K2 said:

 

Yes, it should be, but the area at the bottom of the hood sides should be removed.

 

 

Yeah, I was only referring to the ridge where the arrow is pointing:

 

 

It doesn't exist on the other side, so I figured it should go.

 

Kev

[LSP_K2]

Yep, it definitely needs to go. Fit should be better afterward too.

[LSP_Kevin]

The next challenge is the main chassis frame - especially getting it to fit the cab floor. The instructions give you almost nothing to work with, and neither do the parts themselves. I've taped everything together as best as I can work out, but the geometry looks really off to me.

 

The photos below shows the forward fit, but I have no idea if it's correct or not:

 

 

 

I think it's roughly in the ballpark length-wise, but I'm not so certain about the vertical position. And these close-up photos are really showing me how much clean-up work there is to do on the resin!

 

Here's what it looks like underneath:

 

 

And with the running board more or less parallel to the ground, you can see what looks like quite an upward angle to the rear section, which looks totally wrong to me, and explains the "broken back" look of the model on the box top:

 

 

I need to study some photos of the real thing, but at this stage, I'm not quite sure where to go from here.

 

Kev

[LSP_K2]

Seems like you have some serious warpage issues there, Kev.

[LSP_Ron]

The back of the cab should be a perfect 90 deg to the top of the chassis.  The running boards should be parrellel to the top of the chassis.  I don't think that's warping, I think the front of the cab is interfering with front of the chassis, lifting it up.

[LSP_Ray]

I agree with Ron, I think you need to remove a wedge of resin at the front so that it rotates the cab about 10 degrees.

[LSP_Kevin]

Thanks for the comments, fellas. As it happens, while I was testing various options for fitting the frame to the lower cab section, the frame broke on one side, which left me with really only one way to mate the two components, so I went with that.

 

 

 

You can see the break clearly here, which by itself is no big deal, but I also managed to persuade the two sides of the break to misalign during clamping, which I didn't notice until it was too late:

 

 

I won't be endeavouring to do anything about that, since this is a get it done build, and will only sit in my display cabinet. I might have to address the miscasting under the fender, however!

 

It's looking a lot better now, but the upward tilt of the frame to the rear is still there, even if somewhat diminished:

 

 

Not sure if I'll try to fix that or not. I'll make a decision once I can dry-fit the tray and assess the damage.

 

On thing I will try to fix, however, is the distinct warp to port the frame has in the lateral axis:

 

 

In the photo above, the top edge of the ruler is aligned with the rear edge of the chassis frame, and follows it down to the front, where it is distinctly off-centre. I displayed it this way to best show the deviation, but rest assured that it exists in the rear section, not the front. Hopefully I can fix it with some judicious heat treatment. We'll soon find out!

 

Kev

[LSP_Ray]

Cab sits a lot better, Kev!

[LSP_K2]

1 hour ago, LSP_Ray said:

Cab sits a lot better, Kev!

 

Indeed it does. Nice job, Kev.

[Furie]

You’re gonna make it, Kev, the further treatment is gonna work!

 

 

Edited November 8, 2023 by Furie

[LSP_Kevin]

Thanks, Dennis. I've given it a gentle go, and didn't get a result, so I've decided I'm probably going to leave it. Turns out it's not a simple twist or bend, but rather, the frame is misshapen in multiple dimensions, and the risk of making things worse rather than better is pretty high. In test-fitting the tray, I'm pretty sure I can fudge the alignment so that everything looks OK at a casual glance - which is all I need for this build. But! I may change my mind again yet!

 

In the meantime, I've started working on adding some of the detail parts to the cab and chassis, but I'm having real difficulty identifying the parts as shown in the instructions, and then working out how they're meant to be attached to the model. Very few of the parts look like anything in the drawings, and nothing in the drawings looks like any of the parts! I've figured a few of them out, but it's a real head-scratcher!

 

Stay tuned!

 

Kev

 

[thierry laurent]

The problem with such a resin is that it quickly became brittle when aging... So, you can only rely on heat to get straigth parts and even that is not a guarantee of breakage.

[LSP_Kevin]

22 minutes ago, thierry laurent said:

The problem with such a resin is that it quickly became brittle when aging... So, you can only rely on heat to get straigth parts and even that is not a guarantee of breakage.

 

Yeah, this resin is pretty brittle, but also easy to carve and sand. It has that old-school paraffin smell when you cut or abrade it!

 

Kev