TOPIC:

I've been thinking about how I might drive the reel (big whirly bit at the front) and the head auger (bladed spinny bit to the rear of the reel) ...

Initially I'd been thinking it would be easy to find something like a 540 motor - but much shorter and slower - and hide that in the left hand pod.... probably being very unrealistic there, I need one around 20mm tall (not including the output shaft) & capable of around 30rpm. Some torque would be nice, I don't want the head stalling out if it picks up a bit of grass, a small twig or a feather

I've discounted a lot of options (brushless outrunner: too fat, too faster, more wires than I'd like; coreless brushed motor - too long; syncronous motor: too slow, wrong voltage, often AC; stepper motor: too many wires, added complexity of driving them) & am currently thinking a 380 motor (or similar, possibly with some sort of reducing gearbox) hidden under the conveyor housing (connects the cutting head to the rest of the combine), then belt drive to the middle of the auger, and another belt from one end of the auger to one end of the reel.

Spent a lot of time on drawing plans for this - my usual technique of takign a photo then adding a blank layer in Paint Shop Pro & drawing on that only really works on very slab sided vehicles, on something this, even though there are very few curves, there are a lot of planes at different distances from the lens & the result is a lot of sizing/angle/parralax errors that need a lot of rescaling to fix.

TBH I didn't help myself by doing bits I didn't really need to - the tyre letters are a case in point (paste in one letter, cut out, paste as new image, rotate a multiple of 11.25 degrees, cut & paste pack into the original), and the front view of the reel isn't strictly neccessary. Still, I can make blueprint version of all the views once I've finished & it'll make a pretty desktop background for a while

Rear view plan isn't needed so I didn't make any corrections. I think I'll need a top view though, so will do a basic one at some point.

That's awesome Jonny.

Great, Now all I am singing the entire weekend is "I've got a brand new combine harvester and ill give you the key!" Man , I wish i hadn't have clicked that....

BCM06 wrote:

Great, Now all I am singing the entire weekend is "I've got a brand new combine harvester and ill give you the key!" Man , I wish i hadn't have clicked that....

Try this instead:

I've made some progress on this - but it's mostly been thinking time, so it doesn't show


I haven't used my Lunchbox in several years so was planning to sacrifice that & use the gearbox, rear wheels/tyres to provide the motive power for this, but it seems I'd underestimated the size everything needs to be to match the 1:10 scale of the Fiat tractor I built a while back.

Scorcher front wheels & tyres are almost perfect for the rear wheels (24mm OD x 6mm wide on the 1:32 version, multiply by 3.175 gives an "ideal" of 75mm OD and 19mm width - which compares nicely with the 73mm OD/20mm width of the Scorcher items - even if the tread is "wrong"), I've also been rethinking the cutting head - using a third Scorcher front wheel would give "terrain following capability" and remove the need for electrifying the drive - so at least one less belt & two less pulleys.

I'm not too worried about tyre width, but for 1:10 scale the "ideal" axle would have 152mm OD tyres and a total width of 325mm. The Lunchbox doesn't compare very favourably, with 110mm OD tyres & an axle width of 288mm. A King Blackfoot back end (I really didn't want to sacrifice that truck TBH) is little better at 115mm and 296mm respectively.

The logical thing would be to scale back to 1:12 or even 1:14 ... so my answer will be to use a Clod Buster axle, wheels & tyres, and take a 25mm slice out of the middle of both wheels/tyres to bring the width down.

A new built axle is on its way from IBIFTKH (Rob) on TC; wheels, tyres and rubberised CA glue from eBay. The total cost of these items was unexpected (I had planned on this build being virtually "free", using stuff I already had), so my Konghead based Fuchs 6-wheeler project just got pushed way down the priority list ... I can't say I'm that unhappy about it


I haven't had a whole lot of luck narrowing tyres in the past so that worries me a little, as does making the cutting head drive work, and lift. The rest of it is simply bodywork - though the overall size of it is bigger than I've tackled before. Maximum dimensions at 1:10 scale will be 875mm long, a 553mm wide cutting head, and 344mm tall. Imagine one Clod Buster pushing another one sideways down the road & you wouldn't be far wrong

Tobe honest I have no clue about OD tire proportions, but I seem to understand you're looking for a tire almost the height of a Clod's but narrower. Have you checked the Kyosho Bridgestone terras ("Boss", and "Double Dare") and the newer excellent HPI Mud Thrasher ones? They are much taller than Black Foot's. Somewhat less than Clod's and definitely narrower. Check the dimensions if you can. I really like your project. Heres some pictures, first the Kyoshos and then the Mud Thrashers I am using on my unfinished IH project tractor:





Where are you located by the way?

The Mud Thrashers look pretty good (and a decent price) I'll bear them in mind for the future as I do want to build another tractor at some point. They're 15mm smaller diameter than the Clod tyres though, which is an issue for this build ... and i've already bought the Clod wheels/tyres. Couldn't find the Kyosho tyres to get any information on.

I had the chance to take some reference pictures today so you can consider these brand/model of chevron tires for future tractor and farming vehicles.








Keep up the good work!

Resized the new Clod wheels & tyres - scuffed up the chrome & fizzed the rest off with a strong solution of caustic soda in the ultrasonic tank, then started on the wheels:

- part off the the outer & the inner faces up to & including the inner tyre bead retainers, tidy edges; inside bore of inner face also needed taking back to level;

- part off the mounting face from the remains & tidy edges, on the outside there's 7mm of the hoop remaing, 2mm in the back (less than the height of the locating lugs);

- old outer face becomes new inner face (it gave more offset than way), mounting face is a push fit but not that tight so I bonded it with Dichloromethane. Old inner face becomes the new outer, the two inner bead retainers butt together (& also bonded with DCM); I will tidy up the visible join with epoxy putty before painting.


Tyres - marked up with bands of 18mm & 10mm tape either side of the centre strip, so in total 57mm came out of the centre of the tyres ... in hindsight it would have been better to cut in a staggered pattern so the treads had a 5mm or so overlap.

I used Zap-RT ("rubber toughend") CA glue ... not entirely convinced it's flexible enough, but it did bond quickly & the "no-drip tip(TM)" gave decent contol










ps thanks mongoose - nice work