fledermaus
Master at Arms
luiz, MrT, Christian, Bob and Mike thanks! and sorry for the super long update, still more mods to do but slowly getting there 
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Dora 1/35
- Thread starter fledermaus
- Start date
fledermaus
Master at Arms
Paul and Mike, the germans had plans for a longer, smaller caliber barrel for firing at longer distances, as you can see on this drawing, maybe thats what the company used as reference and why the barrel is so long. the original photo shows the barrel passes just a little more over the end of the front rail car.
original Dora photo, notice the barrel end in relation to the front car
and the photo of the assembled model on the front of the kit box, the difference is way too obvious
maybe they should have done better research on the subject I think
the Taube book Im using has very good reference on Dora, plus other modelers work over the years and finally the internet have good info on the model, that combined is my reference for the kit so far
Abdin
original Dora photo, notice the barrel end in relation to the front car
and the photo of the assembled model on the front of the kit box, the difference is way too obvious
maybe they should have done better research on the subject I think
the Taube book Im using has very good reference on Dora, plus other modelers work over the years and finally the internet have good info on the model, that combined is my reference for the kit so far
Abdin
Duke Maddog
Well-known member
Good information. I'm glad mine was accurate in barrel length; I would have hated to have done all that adjustment. I doubt I could'v e done it nearly as well as you have, if at all. Looking forward to seeing more.
fledermaus
Master at Arms
HI friends, here with a new update on Dora, the work on the barrel is finished. Some changes were made and here it is.To start there is a big part like a sleeve that connects to the breech block that is missing on the kit, to make it I found a PVC drain piece that had the right diameter to make the missing part.
Here you can see the missing part
This is the PVC drain part used
After removing the screw bases and sanding it smooth it looks like this
A small 1.5mm styrene strip is used to make it fit tight on the barrel
After a little sanding and a coat of primer it is dry tested on the barrel
It works perfectly, the gap is supposed to be there as seen on the reference picture
Here the breech block is added to check that all fits with no problem
Now the recuperators’ bases are modified to fit over the PVC plastic sleeve
The lower part is split in half and cut away and sanded down till it fits over the PVC sleeve
A comparison of the original part on top and the modified part bellow
The recuperators main body is installed to check the fit of the modified parts
The lower recuperators main body is also installed and all the parts glued in place, I used a rubber band to keep all in place after gluing all.
Here it is finished and now looks like the original gun part
Now the lifting points on the barrel are also modified to look closer to the original ones
Here is the original kit part
And the reference picture
1.35mm Styrene sheet is used to make the bigger lifting ears
This are sanded to shape and the new hole drilled out
The new lifting ears are glued to the kits bases
Now when the lift ears are glued in place but the position of the ring is offset, the
lifting ear should be straight
The ring has two pegs to align it to the barrel, so I just cut the pins and placed the ring in the correct position
Now it is in the correct position
Next the recuperators cylinders are modified, the end tube is removed and a thinner one glued in place, a verlinden nut is glued to the end of the tube
Comparison of the cylinders after the mod
The smaller recuperator shape is different from the original on the Dora photos so I removed the tube from the base
After removing the tube, the base is sanded smooth
A new tube in the correct shape is made with 3d printing
The new tubes ready to install
Two new rings for the base of the recuperator are made with styrene sheet
Test fit of the rings
To simulate the screws I used 1mm diameter rod
After marking the positions the bolts are glued in place
Here the recuperators are installed to the barrel base
To finish the work on the barrel the rifling is installed, acrylic putty
is used to fill the gap created when the barrel was shortened
And a couple of reference photos
Slowly inching to the painting stage of the gun, the last modifications
to the loading platform, carts and elevators is in almost finished and
work on the base about to begin
Thanks for following!
Abdin
Here you can see the missing part
This is the PVC drain part used
After removing the screw bases and sanding it smooth it looks like this
A small 1.5mm styrene strip is used to make it fit tight on the barrel
After a little sanding and a coat of primer it is dry tested on the barrel
It works perfectly, the gap is supposed to be there as seen on the reference picture
Here the breech block is added to check that all fits with no problem
Now the recuperators’ bases are modified to fit over the PVC plastic sleeve
The lower part is split in half and cut away and sanded down till it fits over the PVC sleeve
A comparison of the original part on top and the modified part bellow
The recuperators main body is installed to check the fit of the modified parts
The lower recuperators main body is also installed and all the parts glued in place, I used a rubber band to keep all in place after gluing all.
Here it is finished and now looks like the original gun part
Now the lifting points on the barrel are also modified to look closer to the original ones
Here is the original kit part
And the reference picture
1.35mm Styrene sheet is used to make the bigger lifting ears
This are sanded to shape and the new hole drilled out
The new lifting ears are glued to the kits bases
Now when the lift ears are glued in place but the position of the ring is offset, the
lifting ear should be straight
The ring has two pegs to align it to the barrel, so I just cut the pins and placed the ring in the correct position
Now it is in the correct position
Next the recuperators cylinders are modified, the end tube is removed and a thinner one glued in place, a verlinden nut is glued to the end of the tube
Comparison of the cylinders after the mod
The smaller recuperator shape is different from the original on the Dora photos so I removed the tube from the base
After removing the tube, the base is sanded smooth
A new tube in the correct shape is made with 3d printing
The new tubes ready to install
Two new rings for the base of the recuperator are made with styrene sheet
Test fit of the rings
To simulate the screws I used 1mm diameter rod
After marking the positions the bolts are glued in place
Here the recuperators are installed to the barrel base
To finish the work on the barrel the rifling is installed, acrylic putty
is used to fill the gap created when the barrel was shortened
And a couple of reference photos
Slowly inching to the painting stage of the gun, the last modifications
to the loading platform, carts and elevators is in almost finished and
work on the base about to begin
Thanks for following!
Abdin
3D Printing in PR or did you order it stateside?
Excellent update, by the way.
Regards,
Excellent update, by the way.
Regards,
fledermaus
Master at Arms
hi saul, I have a ctc 3d printer I got about a year and a half on ebay, now Im using it to make parts for my models this are the first for a model kit I have done, now Im making a 1/35 tiger engine that is on thingiverse for you to download and print for free, its another tool to help me do more super detailing to my kit
saludos desde PR
saludos desde PR
Excellent Update Abdin!
Watching you build this makes me think when It's finished, it will fire shells the size of 1/35th Volkswagens all the way to the Florida Keys!
Fantastic stuff! Lewis Pruneau scratch built a 1/35th Dora back in 1982. It made the cover of FSM. I think you have done more research than he did back then! At the time, we never dreamed there would ever be a kit of it!!!!!!!!
Bob
Watching you build this makes me think when It's finished, it will fire shells the size of 1/35th Volkswagens all the way to the Florida Keys!
Fantastic stuff! Lewis Pruneau scratch built a 1/35th Dora back in 1982. It made the cover of FSM. I think you have done more research than he did back then! At the time, we never dreamed there would ever be a kit of it!!!!!!!!
Bob
fledermaus
Master at Arms
hahaha that's right Bob, Im still debating were to put it when finished. Have a tentative place on top of the computer desk but still have to wait till it is finished to see if it will fit :idonno
Outstanding update Abdin, maybe place it close to the front door as a deterrent to would be robbers?
Thanks for sharing this.
What are you using for CAD program?
Thanks for sharing this.
What are you using for CAD program?
fledermaus
Master at Arms
Bob Im using 123d design to do the 3d files, is a nice and easy program for doing stl files.
Thank you, will check it out. Ah, an old version of Autodesk and their family. Don't let anything happen to it, looks like they don't support it anymore.
I've moved your Dora to your Masters forum, should be much easier to find going forward.
I've moved your Dora to your Masters forum, should be much easier to find going forward.
phantom II
Master at Arms
What an amazing update . Thanks Adbin
I can only wonder why a model company would not do better research , since the information is out there but then there would not be that much for a modeler to do .
Aside of that , do you have all your utilities back ?
Cheers, Christian B)
I can only wonder why a model company would not do better research , since the information is out there but then there would not be that much for a modeler to do .
Aside of that , do you have all your utilities back ?
Cheers, Christian B)
Adam Baker
Active member
Great work! A friend of mine has this kit, and he had done some research, and came to the same conclusion, that the kit barrel was too long. He gave me dimensions for making a new barrel for him, and I had originally intended on machining a new barrel for him out of aluminum, but lost access to the lathes to do it before I could. Now I've thought about machining one out of something like delrin, or having it 3D printed.
Heavens Eagle
Well-known member
I think the delrin would be difficult to make the paint stick to. Making a pattern to do the 3D printing would be difficult due to the size of the parts. No real easy way to do it.
Would have loved to see a machined aluminum barrel for this beast.
Would have loved to see a machined aluminum barrel for this beast.
Adam Baker
Active member
True, hadn't considered the difficulties of getting paint to stick to the delrin.
My plan had been to make it 2 pieces, so that would help some w/ the overall size, but it would still be sizable. The breach portion is about 13 3/8" long and the muzzle end is just over 14" long.
My biggest concern with trying to turn it from aluminum was just the overall weight of the 2 parts. Using 3003 AL, Solidworkks calculates approximately 4 lbs for the barrel, would probably have to add some extra reinforcement to the kit to ensure that it doesn't damage the model over time. Delrin would be about 2 lbs.
Here's the model I created from the dimensions my friend gave me.
My plan had been to make it 2 pieces, so that would help some w/ the overall size, but it would still be sizable. The breach portion is about 13 3/8" long and the muzzle end is just over 14" long.
My biggest concern with trying to turn it from aluminum was just the overall weight of the 2 parts. Using 3003 AL, Solidworkks calculates approximately 4 lbs for the barrel, would probably have to add some extra reinforcement to the kit to ensure that it doesn't damage the model over time. Delrin would be about 2 lbs.
Here's the model I created from the dimensions my friend gave me.
Duke Maddog
Well-known member
One of my friends and fellow IPMS members built this same kit way back in the mid 2000's. He had ordered a turned aluminum barrel for this model as well. Once he got it, he found that the weight of the barrel prevented it from ever elevating. There was never enough ballast in the breach block to allow it to elevate. So, if you intend to model this with the barrel in a perpetual horizontal position, a turned metal barrel will work. However, if you want the barrel elevated, you'd need to glue it into place.
My friend opted to use the kit's plastic barrel instead.
Funny story: When he ordered his aluminum barrel, he did it from a firm overseas. The barrel was held up in customs for months and the FBI even visited him at home to see why he needed it! When they saw his partially assembled model they were amazed at the sheer size and complexity of the model. They also allowed the barrel to be released from customs though....
Adam Baker
Active member
LOL, yea, I could see where something like that could possibly cause some issues.
Weight was always my biggest concern w/ trying to machine it out of aluminum, I knew it could be a problem, and I've tried thinking of ways to counter it. One option would be to bore out the lower barrel as much as possible, to reduce the overall weight.
I think that the best option is to turn it out of some kind of plastic. As mentioned, paint adhesion could definitely be an issue, so it would be a matter of figuring out what kind of plastic to use. I know that delrin & nylon are both available in round stock large enough to machine the size needed, so those would be options, along w/ exploring options for priming the plastic.
Weight was always my biggest concern w/ trying to machine it out of aluminum, I knew it could be a problem, and I've tried thinking of ways to counter it. One option would be to bore out the lower barrel as much as possible, to reduce the overall weight.
I think that the best option is to turn it out of some kind of plastic. As mentioned, paint adhesion could definitely be an issue, so it would be a matter of figuring out what kind of plastic to use. I know that delrin & nylon are both available in round stock large enough to machine the size needed, so those would be options, along w/ exploring options for priming the plastic.