Drop Ship (now with added pew pew)

[dwartist]

"Any other ideas or suggestions?"

Crew! 

[Brandlin]

"Any other ideas or suggestions?"

Crew! 

Kev White's Job...

Maybe you can persuade him to flesh out the Grymn Air crew models..... ?

[Brandlin]

Progress on the hull redesign. I have solved the steep ramp angle problem.

In fact I may have over solved it!



The picture shows the 'false' floor that sits in the cargo bay recess and slides out. The rear door will hinge down as before and magnets in the inside of the door will hold the door up against the underside of the false floor, thus creating a ramp.

When readying for take off, the false floor will slide back into the cargo hold and the same magnets will locate it to the recessed main floor. the door magnets will hold the door shut against the rear hull.

Simples.

The only problem is now that the ramp looks too long! Thats about a 7 degree angle to the horizontal.



I can play with the length of the false floor to get a better look though. Just the hinge and door to redesign now.

[Westfalia Chris]

Only problem I see with that is that anything placed inside will block the movement of the false floor, or am I missing something crucial? That said, it's not a toy, so you don't *have* to actually place stuff inside.

The length of the ramp is another reason why I suggested the ramp sliding on recessed rails beneath a thin floorpiece - it wouldn't need to be the length of the whole bay then.

[Inso]

The ramp looks too long at its current thinkness and to make it thicker would reduce payload. How do you load the cargo? Do you stack it up on the ramp and then close it or do you close the ramp and use a mechanical handler?

I'm not sure the false floor idea sits well.

[Brandlin]

Only problem I see with that is that anything placed inside will block the movement of the false floor, or am I missing something crucial? That said, it's not a toy, so you don't *have* to actually place stuff inside.

The length of the ramp is another reason why I suggested the ramp sliding on recessed rails beneath a thin floorpiece - it wouldn't need to be the length of the whole bay then.

It's a compromise.

You can pose vehicles in the hold and on the ramp, and when stowed the ramp is inside the vehicle, not having to be stored separately.

As I said before, yes recessed rails would be ideal, but I don't have the space to put them in.

The ramp looks too long at its current thinkness and to make it thicker would reduce payload. How do you load the cargo? Do you stack it up on the ramp and then close it or do you close the ramp and use a mechanical handler?

I'm not sure the false floor idea sits well.

Cargo is loaded by going up and down the ramp when deployed. The fact that the ramp is actually the hold floor is a compromise in the model. It's not meant to reflect the actual operation of the 'real thing'...

Looks like this approach didn't go down well. Depressed now.

[Westfalia Chris]

As I said before, yes recessed rails would be ideal, but I don't have the space to put them in.

See, that's what I fail to see - you do have the space right now to run the ramp into the hull - there must be half a millimetre to spare above the ramp slot which you could cover with plasticard to produce a deck? I mean, the concept still uses plasticard to cover the outer hull, or am I mistaken?

I've added a 3-sided diagram below to illustrate how I envision it. Using 2mm MDF for the blue structures and the ramp, and 0,5mm plasticard for the green bay flooring, the whole assembly would be 4.5mm high, and from the proportions of the bay, I'd assume you could put a recess in the bulkheads to take this?

I'll concede I don't know how tricky it would be to add the necessarily round axles at the end (either glueing on a continuous one, or two stubs to the sides) or how tricky those small parts would be to laser-cut. Also, I may be totally off with the dimensions of the bay, but as said, I fail to see how it cannot be done, period.

[Brandlin]

See, that's what I fail to see - you do have the space right now to run the ramp into the hull - there must be half a millimetre to spare above the ramp slot which you could cover with plasticard to produce a deck? I mean, the concept still uses plasticard to cover the outer hull, or am I mistaken?

I've added a 3-sided diagram below to illustrate how I envision it. Using 2mm MDF for the blue structures and the ramp, and 0,5mm plasticard for the green bay flooring, the whole assembly would be 4.5mm high, and from the proportions of the bay, I'd assume you could put a recess in the bulkheads to take this?

I'll concede I don't know how tricky it would be to add the necessarily round axles at the end (either glueing on a continuous one, or two stubs to the sides) or how tricky those small parts would be to laser-cut. Also, I may be totally off with the dimensions of the bay, but as said, I fail to see how it cannot be done, period.

Thanks for the input Chris.

In summary - 4.5 mm is a large dimension on this model. For scale, the recess in the floor currently is 3mm.

Let me try and explain the problem in a little more detail.

Your solution requires that the end of the ramp remains in the end of the slot in the hull and pivots downwards to form the ramp. Your diagram only shows the ramp in its horizontal position.

The 'rod' on the end of the ramp needs to be say 2mm in diameter so it doesn't easily snap or bend (lets worry about how it affixes later) and you need a couple of mm of material in the end of the slot - to stop the ramp sliding out. this then means that the pivot point for the ramp is actually around 4mm back from the door into the hull. You can see this if you look at your own side elevation drawing and imagine the ramp slid to the end of the slot, the centre of the hinge pin is now a few mm back from the door sill.

Now draw the ramp deployed at an angle rotated about the hinge point 4mm back from the door. You'll see that the underside of the deployed ramp then fouls the lower edge of the current door sill. The solution to this would be to lower the door sill just on the outer edge of the door frame. Unfortunately to get door height I have already taken that to its practical limit. There is only 2mm of supporting material in the end cross-section that forms the doorway. I can just about get away with this because as you see i have plenty of supporting elements holding that rear frame.

Note for scale that rear chamfer on the hull is only 5mm deep, so what sounds like a small amount is actually quite significant.

To resolve this I would need to raise the floor of the overall cargo bay - thus negating the benefit of having the sunken section as currently shown.

The curve of the underside of the hull means that the sill could be lowered by making the ramp narrower. I have played around with this but in order to get the necessary clearance on the door sill you end up with a ramp only around 30mm wide. So this isn't practical.

The other issue with your suggestion is the issue of rails. If the pivot pin of the ramp is 2mm brass rod (which is what i would use to make sure it doesnt bend etc) and you run it in a slot, then you need a couple of mm of material above and below the rod - allowing for clearances to prevent binding, you end up with 6.5mm + of height not 4.5mm

Your picture actually doesn't show rails. It shows the rod on the ramp section running on the underside of the thin floor piece. My biggest concern with this is that if the ramp is pulled out part way and any pressure is applied to the ramp end, then you have a lever that is going to try and push the thin floor upwards. I may be being paranoid but that's not ideal to me.

Rather than attempting to affix a pivot pin at the very end of the ramp, a simpler solution would be to cut the ramp with a couple of stubs that stick out laterally at the very end. However they would need to be 3mm or more in thickness and this would then cause more problems with the actual pivot point for the ramp and cause upwards pressure on the floor again. I also think this will bind more often.

Your comments about using styrene sheet to cover the hull floor are good ones and it is an ongoing option. I think 0.5mm would be too thin for this, and I was thinking of diamond plate which is usually in 1mm sheets. The impact is simply a loss of 1mm of height.

The compromise solution then is that the ramp is a separate piece. It slides into a slot under the floor. When the ramp is deployed, it affixes to the inside of the lowered rear door on magnets that hold it in place, and provide a nice strong ramp. When the ramp is stowed you simply detach those magnets and slide the ramp end into the 'slot'. A simple stop in the slot could be used to prevent the (probably shortened) ramp from sliding out of reach and jamming. again a small magnet in the floor could hold it in place just to prevent it from falling out.

Having the ramp as a separate piece means that I can play with the pivot location of the rear door hinge and position the ramp on the door so that there isn't a gap between the lowered door and the door sill (caused by the door pivot point not being flesh with the rear door frame). This means you would have a nice smooth transition for your vehicles from ramp into hold.

My preference is to have some detail on the hull floor. If the floor is a single 1mm sheet then this can be engraved. Engraved sheets lose a lot of strength so i need to be careful that I don't over weaken the sheet. Im just a little concerned that the floor stands up to the rigours of figure and vehicle movement, because if the floor buckles then the ramp may bind/jam.

The same goes for the ramp itself. some surface features would be far better than just a plain 'slab' of styrene (something like Hazard stripes down the sides and direction of loading arrows). On the ramp I can probably laminate 2 or more styrene sheets and either engrave the top one or have a thinner top sheet fully cut through to make the detail.

There was a comment made earlier about the risk of paint jobs being ruined with sliding pieces. with my solution here, if you are really worried then you can store the ramp separately and just pretend that its stowed in the ship i guess.

As a point - there is no MDF in this design. Its not strong enough and too bulky. The thin section wooden components are 1.5mm ply- used for aircraft models. It is far more rigid, lighter, but most importantly can be cut to much thinner pieces and retain enough strength. MDF tends to delaminate and otherwise crush in small cross sections.


Sorry for the long post Chris. I hope this explains the situation more fully. I appreciate your and everyone else's comments.

I know it must sound as though I am being anally retentive about such small tolerances in what is effectively just a wargamming model, and i admit that I am trying to squeeze a lot into a relatively small space - and one that is a shape i like but is highly impractical. But hey, I'm having fun. And i hope to produce something a bit special.

[Westfalia Chris]

Alright, thanks for explaining it at length! Now I see, my bad - with those tolerances, it's indeed a very tight spot, and probably not practical. I had guesstimated something like 10-12mm for the bottom part of the bulkhead (I scaled the whole thing in my head something the size of the Tau Orca, or a Thunderhawk).

On another note, have you considered adding a recess at the rear bulkhead, so that you could just slot in the ramp as a separate piece? That will possibly have issues in that you would need an angled cut, or construct the slot part from multiple small parts, but it would alleviate the problem of having to make the ramp move into the hull.

While I am all for fun toys and having a working ramp would be awesome, in some cases, you probably can't have all those moving features. That said, while I originally found the dropping floor of the UD-4L a bit iffy, now I see how it is a very practical solution to the issue.

[Brandlin]

Alright, thanks for explaining it at length! Now I see, my bad - with those tolerances, it's indeed a very tight spot, and probably not practical. I had guesstimated something like 10-12mm for the bottom part of the bulkhead (I scaled the whole thing in my head something the size of the Tau Orca, or a Thunderhawk).

On another note, have you considered adding a recess at the rear bulkhead, so that you could just slot in the ramp as a separate piece? That will possibly have issues in that you would need an angled cut, or construct the slot part from multiple small parts, but it would alleviate the problem of having to make the ramp move into the hull.

While I am all for fun toys and having a working ramp would be awesome, in some cases, you probably can't have all those moving features. That said, while I originally found the dropping floor of the UD-4L a bit iffy, now I see how it is a very practical solution to the issue.

No problems Chris - I appreciate the interest.

Lets be honest here, this is all scaled originally around a listerine mouth wash bottle! So its going to come with challenges!

Its a reasonably big ship - it will end up at around 270mm long, 175 wide and 123 tall including tailfin.

Interestingly I do like the Tau Orca - best thing forgeworld has done in my opinion - but I am not a fan of the suits. I'd want one that deployed tau tanks and APC's. But when i scaled that up to an accommodating size it was scary big!

EDIT: just went to check forgeworld site, do they not make the orca anymore??

remember this is Mk1 the light scout and Renaissance deployment ship. There should be plenty more opportunity for other designs and solutions on the heavier Mk2 version and onwards...

I think this will look like a 'working ramp' on a toy as you say - the only difference is that the ramp does come all the way out.

[Westfalia Chris]

No problems Chris - I appreciate the interest.

Lets be honest here, this is all scaled originally around a listerine mouth wash bottle! So its going to come with challenges!

Its a reasonably big ship - it will end up at around 270mm long, 175 wide and 123 tall including tailfin.

Interestingly I do like the Tau Orca - best thing forgeworld has done in my opinion - but I am not a fan of the suits. I'd want one that deployed tau tanks and APC's. But when i scaled that up to an accommodating size it was scary big!

EDIT: just went to check forgeworld site, do they not make the orca anymore??

remember this is Mk1 the light scout and Renaissance deployment ship. There should be plenty more opportunity for other designs and solutions on the heavier Mk2 version and onwards...

I think this will look like a 'working ramp' on a toy as you say - the only difference is that the ramp does come all the way out.

I think I pin-pointed it now - when you started showcased the spar-and-bulkhead design, I just assumed you'd moved away from the bottle SIZE, while keeping to the bottle SHAPE. That's of course a totally different spacekettle of spacefish.

[Brandlin]

I think I pin-pointed it now - when you started showcased the spar-and-bulkhead design, I just assumed you'd moved away from the bottle SIZE, while keeping to the bottle SHAPE. That's of course a totally different spacekettle of spacefish.

I have moved away from the bottle size somewhat - this is over double the 'thickness' (height), but due to my limitations on space for display and storage its not far from the original bottle width and length.

you'll have to OK my concepts for the heavy version chris, that way you'll get what you want and you can buy a dozen and make it worth my while designing :-)

[Brandlin]

I am beginning to think i'm late to this dropship party and have a second rate solution...

:-(



Those rows of folded seats are so similar to what i've been thinking but not yet drawn.

[Inso]

Merlin Helicopter:

[Brandlin]

Merlin Helicopter:

Thanks inso a remarkably clear interior shot that one.

Those seats look comfier than the ones I flew to Iraq on in a C130J! :-(

I'm not looking forwards to doing any of the 'softer' shapes - as i need to swap cad systems to do that.