3D printable Cromwell Mk. IV in scale 1/16 by Warprints
#1

Hi,
after a year of searching for historical documents and drawing, I finally print.
First Cromwell prototype is being assembled.New parts are added every day.
I worked hard on authenticity.
Perhaps later I will be able to show you pictures of parts in direct comparison with a real vehicle.
As regards the technical side - I have developed a new type of 3D printed belt tensioners for Cromwell. They perform a rotary movement (unlike the linear tensioners used in Hetzer).
Two different rings and three types of motors can be used to rotate the turret.Have 22 moving parts like hatchets and machinegun right now.
Cromwell will be available like KIT or STL files for 3D print as soon as I finish the tests.
I will bring new info and photos soon.
Printing with ASA natural, PET(G) white and Anycubic resin (skin).
I dont use PLA.Never.
Some details, especially on the resin parts, will be better visible when the primer will be applied.












after a year of searching for historical documents and drawing, I finally print.
First Cromwell prototype is being assembled.New parts are added every day.
I worked hard on authenticity.
Perhaps later I will be able to show you pictures of parts in direct comparison with a real vehicle.
As regards the technical side - I have developed a new type of 3D printed belt tensioners for Cromwell. They perform a rotary movement (unlike the linear tensioners used in Hetzer).
Two different rings and three types of motors can be used to rotate the turret.Have 22 moving parts like hatchets and machinegun right now.
Cromwell will be available like KIT or STL files for 3D print as soon as I finish the tests.
I will bring new info and photos soon.
Printing with ASA natural, PET(G) white and Anycubic resin (skin).
I dont use PLA.Never.
Some details, especially on the resin parts, will be better visible when the primer will be applied.












The following 4 users liked this post by 50koruny:
#2

Following with interest, Tomas, so count me in for the kit once ready.

The following 3 users liked this post by 50koruny:
#4

Very nice! Looking forward to getting this kit. 
Aside from fasteners bearings & shafts, what other metal parts, if any, will come with the kit?
Also could you offer some details on how you plan to employ a track tensioner? That tends to be a sticking point for me given what I experienced with another brand that shall remain nameless here.

Aside from fasteners bearings & shafts, what other metal parts, if any, will come with the kit?
Also could you offer some details on how you plan to employ a track tensioner? That tends to be a sticking point for me given what I experienced with another brand that shall remain nameless here.
#5

Very nice! Looking forward to getting this kit. 
Aside from fasteners bearings & shafts, what other metal parts, if any, will come with the kit?
Also could you offer some details on how you plan to employ a track tensioner? That tends to be a sticking point for me given what I experienced with another brand that shall remain nameless here.

Aside from fasteners bearings & shafts, what other metal parts, if any, will come with the kit?
Also could you offer some details on how you plan to employ a track tensioner? That tends to be a sticking point for me given what I experienced with another brand that shall remain nameless here.
ME TOO!!! Images look very crisp and detailed. I want a British tank.

The following users liked this post:
herrmill (05-20-2021)
The following users liked this post:
herrmill (05-28-2021)
#7

Chatted earlier last weekend with Tomas & he's busy on turret details so expect you'll see updates soon.
Based on what he told me, we may well see a working prototype sometime in July or perhaps sooner.
Based on what he told me, we may well see a working prototype sometime in July or perhaps sooner.

Last edited by herrmill; 05-28-2021 at 04:19 PM.
#8

Sorry guys,
i was busy so i dont have posted nothing.
Dont worry, i am working on the Cromwell everyday, even if i dont post nothing.
Have finished 3D model of the turret.There are some of my favourite details.
I am pretty happy with the results.Going to make pictures of the turret soon.
Printing tracks right now.
There will be motors, servos, magnets, track pins and few other things included in the kit.
Basically anything needed for the building, excepting control unit, smoke, sound, transmitter and receiver.
Track tensioners will be fully reinforced with screws.They will work like real Cromwell tensioners.
They are designed to be as durable as possible.
Have some news.Engine covers and the exhaust.











i was busy so i dont have posted nothing.
Dont worry, i am working on the Cromwell everyday, even if i dont post nothing.
Have finished 3D model of the turret.There are some of my favourite details.
I am pretty happy with the results.Going to make pictures of the turret soon.
Printing tracks right now.
There will be motors, servos, magnets, track pins and few other things included in the kit.
Basically anything needed for the building, excepting control unit, smoke, sound, transmitter and receiver.
Track tensioners will be fully reinforced with screws.They will work like real Cromwell tensioners.
They are designed to be as durable as possible.
Have some news.Engine covers and the exhaust.











The following 4 users liked this post by 50koruny:
#9

Looking fine, Tomas!
#10

Thank you.
I have some big update.Turret is almost done.
Here is a video of the gun.
Gun was tested with Arduino Nano.Later it will be controlled with the IBU2, most propably.
Going to make some photos of the details on the turret (there is a lot of details for this scale), but it need to be painted with a primer.
Details are barely visible on that white plastic.
I have some big update.Turret is almost done.
Here is a video of the gun.
Gun was tested with Arduino Nano.Later it will be controlled with the IBU2, most propably.
Going to make some photos of the details on the turret (there is a lot of details for this scale), but it need to be painted with a primer.
Details are barely visible on that white plastic.
#11

Nice work as always. Tomas! Looking forward to seeing the running prototype. 
That added detail you mentioned over on RCTW blow me away about using PMMA for the clear lens for added detail & durability.

That added detail you mentioned over on RCTW blow me away about using PMMA for the clear lens for added detail & durability.
Trying to print lens for the lights from the PMMA filament (plexiglas) instead of the transparent resin.
It looks more interesting because of the patterns.
And it will be more durable, of course.
Unpainted transparent resin doesnt last very long when used in exterior.
It looks more interesting because of the patterns.
And it will be more durable, of course.
Unpainted transparent resin doesnt last very long when used in exterior.
Last edited by herrmill; 06-13-2021 at 03:07 PM.
#12


Looking good.
#13

Thank you, guys.
Turret is painted with a primer, all parts are installed, including that PMMA lens.
Light is working, of course.It will be included in the next video, with all other details of the turret.
For now, i have this video with the Commanders hatch.
This hatch contains 5 movable parts.
Turret is painted with a primer, all parts are installed, including that PMMA lens.
Light is working, of course.It will be included in the next video, with all other details of the turret.
For now, i have this video with the Commanders hatch.
This hatch contains 5 movable parts.
#15

Sorry, but i still dont know nothing about price.I need to assemble at least one complete vehicle to estabilish price.
My Hetzer is about 350€, Cromwell will cost more, but not much more.
Have new video with the turret walkaround.
Tried to catch all detailed parts on the turret.
I can make photos of this, if somebody want.
My Hetzer is about 350€, Cromwell will cost more, but not much more.
Have new video with the turret walkaround.
Tried to catch all detailed parts on the turret.
I can make photos of this, if somebody want.
#16

That IS nice!
#18

Thank you.
Have received all that hardware, finally.
Here is video of the suspension system.
Springs are adjustable, range is 3mm.
They can be possibly changed for some thinner type.
Need to be tested in real terrain.
Arms are printed with ASA, 80% infill.They can take some serious punishment.
Have received all that hardware, finally.
Here is video of the suspension system.
Springs are adjustable, range is 3mm.
They can be possibly changed for some thinner type.
Need to be tested in real terrain.
Arms are printed with ASA, 80% infill.They can take some serious punishment.
The following 5 users liked this post by 50koruny:
Buckeye36 (08-06-2021),
herrmill (07-22-2021),
jha13 (07-22-2021),
tankme (07-21-2021),
Will01Capri (07-22-2021)
#19

Looks very good, Tomas! Nice travel, bulletproof construction and with rubber tyres just like it should.
#20

Hi guys,
first prototype is assembled.
My HDD is in the recovery lab, but i have saved Cromwell.I was lucky, files are on the cloud.
Need only to finish few pages of the assemblu guide.
I hope i can release STL files within few days, printed kits coming soon.Printing first serial parts.
I will make some videos soon.
Here are some pictures of the prototype.Just a small selection.There is more than 150 pictures in this album:
https://photos.app.goo.gl/fr2BHi2JR1H7VtJi9

























first prototype is assembled.
My HDD is in the recovery lab, but i have saved Cromwell.I was lucky, files are on the cloud.
Need only to finish few pages of the assemblu guide.
I hope i can release STL files within few days, printed kits coming soon.Printing first serial parts.
I will make some videos soon.
Here are some pictures of the prototype.Just a small selection.There is more than 150 pictures in this album:
https://photos.app.goo.gl/fr2BHi2JR1H7VtJi9

























#21

That's perfection, Tomas! Couldn't ask for anything more.
Looking towards getting a kit. When will it be offered on your eBay store?

Looking towards getting a kit. When will it be offered on your eBay store?
#22

Thank you.
for now, there will be only bits and parts in that eBay store.
Need more printing capacity again.There are lots of reservations for kits.
Have waiting list, so i dont have chance to get some kit in stock to be offered on eBay.
But i definitely want.It will be great.Working on that.
for now, there will be only bits and parts in that eBay store.
Need more printing capacity again.There are lots of reservations for kits.
Have waiting list, so i dont have chance to get some kit in stock to be offered on eBay.
But i definitely want.It will be great.Working on that.
The following users liked this post:
herrmill (08-04-2021)
#23


Only thing I worry about is melting in the sun. I had my 3D printed SU-152 out in the TX sun this weekend and the rear deck with the engine hatches is warped pretty badly due to the sun and it's a couple of mm thick. Thinking I will have to heat it up and put some bracing under it or it will just do it again.
#24

My first 3D printed tank ever was printed with PLA and it was melted on the direct sun.First day of first show.
Just normal sunny day.Nothing extreme.
After that, i dont use PLA anymore.
My last T-14 Armata is in Australia.95% of this tank is printed with ASA.
It can withstand 90°C (194,0 ° F).
My usual models with use of resin can withstand 85°C.
I have throwed out all PLA, i dont have problems like this anymore.
I dont know about any melted model, builded from any of my kits.
They have the same temperature resistance like classic plastic RC tanks.
Just normal sunny day.Nothing extreme.
After that, i dont use PLA anymore.
My last T-14 Armata is in Australia.95% of this tank is printed with ASA.
It can withstand 90°C (194,0 ° F).
My usual models with use of resin can withstand 85°C.
I have throwed out all PLA, i dont have problems like this anymore.
I dont know about any melted model, builded from any of my kits.
They have the same temperature resistance like classic plastic RC tanks.