Case Study - Tiger Tank Project



Al's German Tiger Tank ProjectAL Johnston is a retired hobbyist with over 20 years experience in manufacturing and assembly in a metal production plant, and carried out manual machine work using lathes, bridgeports mills, cnc plasma and gas table cutting and some cnc machine operator work.

After retiring a few years ago, Al has time to put his passion as a CNC hobbyist to good work with his machinery and software, including a DIY Joe's CNC Hybrid (modified to a CastCNC machine), using a HobbyPro driver board, 28 VDC DIY PS, Hitachi 2-1/4hp router, Mach3 driver software, DesignCad 3D Max V19 Cad software, and of course Vectric's Aspire software.

After speaking with Al, he explains why he took on the Tiger Tank Project, and his initial concerns before production.

"This is all a hobby to me, and being retired on a fixed income, progress can be rather slow at times. What you see in my post has taken me from Aug 2010 to the present (May 2011) to complete, with many setbacks and redo's due to finding the right material and better ways of doing it, mainly on the track link's which took 4 redo's of using different low cost material before I settled on a way of making them, and they are still not 100% correct to my satisfaction, but close enough so as to move forward some."

"Going into a project like this where no one else seemed to have gone can cause a lot of research and development into what type of material to use, ways of designing the parts in the material used and trying to stay as to scale looking as possible up to a reasonable point....etc...etc."

Al's forum thread (found here) has fuelled an exciting following since the very first post, boasting about how powerful Vectric's Aspire software is. Al promotes how Aspire can be used to create much more than users may initially believe.

Tiger Tank Tracks"Just to show that Aspire can do more then just signs, box's or cute engravings. The following pictures show what else Aspire can do! Yep, all done using Aspire!! A start on a German TIGER Early model Tank! Wheels made from poplar wood and track made from PVC house siding trim. A static model only, 1/6th scale." (click an image to enlarge)

Tiger Tank Tracks 1 Tiger Tank Tracks 2Tiger Tank Tracks 3

Following the images, further photos were posted to the Vectric Forum showing the projects development. This time Al was showing how he cut the sprockets and idler wheel...

Sprockets 1 Sprockets 2 Sprockets 3 Sprockets & Idle Wheel 1 Idle Wheel 1 Sprokect & Idle Wheel

Requests for more images and pleas of progress reports followed, to which Al kindly responded to. Al describes the project in further detail, including the techniques he used to progress with such am ambitious project.

Despite expectations that Al is an expert Aspire user, he admits he is still a novice with Vectric's Aspire software, showing just how user friendly the software really is!

"....OK I will keep posting pictures as I make headway on this project. Its a slow project, I had to do a lot of R&D work just to get to this point so hang in there as it slowly takes shape. This is reverse engineering of a 1/35th scale plastic model which I CAD up the parts to 1/6th scale and then plan out the cuts in Aspire. Its not 100% scale or that exact, just close to scale as I can get it.

I think the hardest part so far was finding an inexpensive material to make parts from that held up from tear outs and wood fuzzys... I believe this is the 4th try on the track links before I settled on PVC house trim as the material of choice.

My main objective was easy, to get a low cost of material, so far I've gotten all of it from the local Lowes (not the lowest cost by any means), even the paint is marked down mismatched paint from Lowes. So yes, this is time consuming but its just a hobby to me in my old age to play with in my retirement.

For cutting I use a DIY modified Joe's Hybrid CNC mill, converted to a CastCNC mill which is an all Alum mill built with 8020 beams and cast Alum trucks running V-bearings. HobbyPro driver board, 425oz steppers, 30V PS, Mach3 driver software and Aspire as my gcode generator of my designs I do in 2D CAD (DesignCad3DMaxV19). I also use a Harbor Freight Mini-mill to do drilling and some mill work on, plus a HF Mini-lathe also. I don't have a shop, instead I operate in a small spare room in the house where space is at a premium."

"Below is the Drive Sprocket... made from glued up poplar wood with replaceable ring gear bolted to rim. Cut with Aspire using the 2rail sweep method. Yes, it can be done!!"

Drive Sprocket 1Drive Sprocket 2Drive Sprocket 3Drive Sprocket 4

User: Khalid: Hi Al, seems you really mastered Aspire...The Drive Sprocket seems to be professional with all intricate curves....The results are stunning...

User: dewalt58 (Al): I wish.....I'm still in the dark on a lot of things in Aspire... It's just what the 2 rail sweep can do for you if you play with it, really very easy to do! Once you see how it works you can envision all sorts of possibilities using it!

I have a tutorial made on how I made the 2 rail sweep on the sprocket, if enough of you are interested I'll post the way I did it! Soooooo....lets see a show of hands as to who wants to see it!... AL

View Al's Two Rail Sweep Method

Following Al's progress on the forum has been enjoyable to say the least, learning about his approach when producing the sprockets using Aspire's two rail sweep tools, through to the videos (as below) of cutting parts for the tank!

Cutting the sprocket:

Cutting the road wheels 1 of 2

Cutting the road wheels 2 of 2

Video of the sproket being cut! Video 1 of the road wheels being cut! Video 2 of the road wheels being cut!

As mentioned previously, this Tiger Tank Project is a creation of an enthusiastic CNC hobbyist, showcasing how Aspire's ease of use can help you create exciting projects such as this.

You can read the entire forum thread here where Al has informed us he will post any further progress of his work. Al has confirmed that the Tiger Tank is time consuming on his behalf, and that he started the project simply as a challenge to see whether it could be done,

"I've satisfied myself that it can be done with Aspire, so time to move on to other projects of challenge.", Al Johnston

Fingers crossed we see more work in the future, including a completed German Tiger Tank model!

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