doug72

Tommy, I have adapted your design to suit stud-less construction with side beams 13L apart. The unit incorporates an Efferman worm drive housing for the steering input - it gives 8:1 and uses and two 8T gears to get correct centres. Biggest challange was to support the two 16/24T diffs in the centre - hence the two 5 x 7 frames in the middle. My two axle 2 speed unit is used - at present with hand change over - have to find a way to operate from outside the unit. Fast speed 5:1 reduction Slow speed 15:1 reduction. L motor for propulsion and M motor for steering. Motor mountings to improve later when installed. Final drive to tracks is 3:1 and both speeds give desired track speed and steering. Next step build into my Gyrotiller MOC. Underside view: IMG_4162 by Doug Ridgway, on Flickr Top view: IMG_4161 by Doug Ridgway, on Flickr

Now completed this unit and it works very smoothly - increased the bracing of the worm and there is no binding anywhere or slipping of gears in either high or low gear. Used an L motor for drive and M motor for steering - position of motors in photo just for testing purpose. Thanks for a great compact design - I certainly will be using it and maybe upgrade my Gyrotiller MOC. IMG_4154 by Doug Ridgway, on Flickr

Tommy, tried that and works OK - turned so now vertical and supported by the 2 x 6L thin beams to the centre support with a 2L axle/with ipin and a spacer bush. Have an idea for strengthering the worm drive mounting which will try out tonight. I am building it between stuudless beams so have to add 1L on one side to make frame spacing 13L.

Tommy, I am currently building this following the LDD build pages and have a problem. When I reached step 27 and put the 12T black double bevel gear in place, found that as the differential casing rotates it fouls the 12T double bevel gear. It can forces itself past the black gear in one direction but not in the other. Maybe this is the cause of the slippage you mention. Checked and rechecked that I have built it correctly as per LDD. Tried a 12T single bevel gear but still the same problem.

Tommy, looks to be a very interesting concept. As you say a subtractor unit plus 2-speed transmission can take a lot of room in a model as i found for my Gyrotiller MOC. Which motors are you using for drive input and steering input ? Have downloaded the LDD file to study and will try and make a studless version. Doug

Definitely won't be tested on mud, too sticky but dry sand should demonstrate the digging action. Had a set back in that the tracks are very jerky when in motion and machine tended to adopt a "waddling" side to side motion. Found one axle in subtractor unit not supported at one end - fixed but still the same ! Subtractor unit removed and two XL motors now drive the tracks. Still a bit jerky but can't find a way to improve this - as the track links passes over the sprockets and track rollers the machine lifts slightly. Anyone got any ideas on improving this? Drive to the 3 cyl. engine is now taken from the Gyrortiller motor.

Thanks for the comment - I enjoy the challenge of working out drive trains to get various functions working in as small a space as possible. Gyrotiller unit now modified for remote operation for tiller rotation & raise/lower unit. It took a long time to get the pivot points correct to ensure it lowered to full working depth and raised so cutting blades clear of the ground for travelling. Lifting frame fitted with two shock absorbers to allow tillers to lift if hit an obstruction. Two PF receivers now fitted and all 4 functions are now remotely controlled. Driver elevated to a higher position to allow the PF cables to be hidden from view and see over the radiator ! Gyrotiller raised into travelling position IMG_4151 by Doug Ridgway, on Flickr Gyrotiller lowered into working position: IMG_4150 by Doug Ridgway, on Flickr The completed model: IMG_4152 by Doug Ridgway, on Flickr

Thanks for the comment - no computers, GPS or comforts when these machines were built ! Here are some close up images. Track unit with side cover removed showing tensioning device suggested by Milan which works well. Unit is a modified 8043 excavator design without the two top track rollers. IMG_4146 by Doug Ridgway, on Flickr Underside of machine showing layout of motors and subtractor unit. IMG_4147 by Doug Ridgway, on Flickr Top view of Gyrontiller unit. IMG_4148 by Doug Ridgway, on Flickr Underside of Gyrotiller unit showing drive to each rotating tiller. IMG_4149 by Doug Ridgway, on Flickr At the moment the digging depth is too shallow as the gyrotiller unit frame pivot is too high. This is to be lowered by 1 or 2L with new arrangement to power raise & lower remotely. There is space now after 2-speed gearbox removed as it is no longer needed. History & story of the Gyrotillers:- http://tractors.wikia.com/wiki/Fowler_Gyrotiller

Thanks for the comments - I will put some close up pics up of the gyrotiller unit & underside of the chassis later. Have an idea for powering the lifting frame - will see if I can squeeze it in plus another PF Rx.

My latest MOC, a representation of a Fowler 80hp Diesel Gyrotiller. (the MOC is based on the fact sheet below) The MOC has gone through several phases, i.e. build - test - strip down - rebuild until satisfied with the result. IMG_4145 by Doug Ridgway, on Flickr Originally I used 3 M motors to power all the functions:- 1/. Track drive with provision for 2 speeds, (1:1 & 3:1) but tracks still lacking power and straining the motor. Changed to an XL motor without 2-speed gearbox for more track power at a slow speed and now OK. The 3 cylinder engine and radiator fan are also driven by the XL motor. 2/. Steering via 3:1 reduction. 3/. Rear Power take off. The battery box represents the fuel tank. Provision for the driver is very basic as was the actual machine built by Fowlers - a full cab version was available at extra cost. Track drive and steering Built using a subtractor unit with an XL motor for track drive and M motor for steering and controlled via PF remote. First subtractor unit I built using the Z28 differentials was a failure causing tracks to be very jerky - replace with a unit using the 16/24T differentials which worked much better - final drive via worm gear boxes to each track. Power Take off is provided by an M motor operated via a PF switch in the cab. IMG_4143 by Doug Ridgway, on Flickr Caterpillar tracks: This took a long time to get working well - eventually settled on a track system similar to that used on the 8043 Excavator - modified by fitting track tensioning devices. (as per other posts) Gyrotiller unit: Consists of two Z60 turntables with cutting blades on a lifting frame that contra-rotate via a 3:1 reduction from the M motor. The cutting blades are made from 8 clam shell bucket arms.(6100179) The frame lifting system on the actual machine is via engine driven winch drums and chains running over quadrants and quite complicated to replicate in the space available so I settled on using manually operated mini linear actuators. I may try a powered arrangement later. I might also make a sand tray to see how it performs actually ploughing and make a video. IMG_4144 by Doug Ridgway, on Flickr Its big brother a 170hp Gyrotiller is a monster on half tracks with a single steering front wheel and would be a challenge to build - maybe in the future ! UG7047 Fowler 170hp Gyrotiller 1935 World Ploughing Contest Crockey Hill York 9.9.16 by George Woods, on Flickr I have seen one working at a Steam rally and they are an amazing sight churning up the ground with ease. See web link:- http://tractors.wikia.com/wiki/Fowler_Gyrotiller 80hp-Gyrotiller by Doug Ridgway, on Flickr Fact Sheet The Fowler 80hp Gryotiller is a a large tractor built by John Fowler & Co. of Leeds, England. They were fitted with a pair of contra rotating bladed drums to cultivate ground like a rotovator or modern power harrow. They were often used to break ‘virgin’ ground as the rotating blades chopped up roots and bushes. They also broke up sub soil without bringing it up to the surface.

Don't see how you propose coupling a 16T clutch gear to the 24T gear to drive together ! 3D printing expensive and as I have lots of spare white 24T clutch (slip) gears it is a cost effective & simple solution.

Yep. Because my version only requires 2 axles and 4 gears as against 3 axles and 7 gears for the Go-kart version. Mine was built as a module using 7 x 5 frames for easy attachment into MOC but could be installed between two beams 7L apart with c/o lever. For my MOC I may need another 2-speed unit so may try the go kart version. The mod of the 24T clutch gear is not my idea it has been used in the past I believe for a modification for the Front Loader 8265 A Lego version would be a desirable addiion the Technic gears.

Yes they are quite easy to modify: 1/. Place 24T white gear with the side that has 4 small locating slots with tabs face up and support the gear teeth rim with 1L thick beams at several places on a hard surface. 2/. Using a 6mm diam. steel rod place over the centre grey axle bush and with a sharp tap with a hammer knock out the internals. Discard the white part with grey bush and 2 small thin steel plates 3/. From the remaing 24T white gear part remove the 4 tabs - they snap off easilly. 4/. Insert a grey 16T clutch gear making sure the boss on back of the gear goes through the hole to slightly stick proud ( about 0.5mm) You may need to enlarge the hole very slightly to allow the boss of the 16T clutch gear to pass through. 5/. No need to glue in as friction is usually enough to stop any slippage between the two parts.

For a MOC (WIP) I am currently attempting to build I required a 2 speed gear box to allow for the caterpiller tracks to run either fast or slow. Fast when traveling to & from work site. Slow when working. I have developed a compact gearbox with two axles using the old style driving ring to select the required gear as seen in images. Top View: IMG_4139 by Doug Ridgway, on Flickr Underside view: IMG_4140 by Doug Ridgway, on Flickr To achieve this a white clutch (more correctly termed a slip gear) was modified to become a true 24T clutch gear, I belive this was once proposed for a modification to the Front Loader set 8265 but unable to locate this on old forum postings. IMG_4138 by Doug Ridgway, on Flickr The internals of the white 24T gear are removed and replace by an 16T grey clutch gear - push fit is adequate without need to glue in place. Result a 2-speed gearbox that takes up very little space.

I have just checked the 8 spares I have and all are OK but cannot find any markings on any of them which include some from the BWE set.

Looks good and quite large. I too use the "M" word and base technic models on found in Meccanno books I have. In my childhood I used to build cranes with a No. 9 set, never managed to get a no. 10 set. I built a Giant Block Setting Crane back in 2014 - its based on a crane that used to be on the South entrance pier to the river Tyne. Sadly cut up for scrap many yeasrs ago. See this post. The links to images and videos are not working after the site software upgrade. Images can be found on on Flika Album on botton of page 3. Doug

Sariel, yes I am aware of it but wanted to build one in studlless and using the 28Z differential to eleminate the right angle drives. Not keen on studded construction prefer studless. Doug

When building tracked vehicles I prefer to use a subtractor unit for drive and steering using the 16 / 24 toothed differentials. With motors attached these can take a lot of space in a MOC. Additionally two right drives are required to the track drive sprockets. Found a better solution in Sariels excellent guide book for a Studless Transverse Subtractor unit shown on pages 291/2. These worked but found awkward to incorporate in my MOCs due to its cube shape. I set out to build a “flat” version using 28Z differentials and after a lot of trial and error achieved success. Unit measures 13L wide x 7L long x 4L deep without motors. has the added advantage that the right angle drives are no longer required to the drive sprockets. For my planned MOC the drive input will have an 8:1 reduction and steering input a 24:1 reduction to get the very slow track speed I require. I have built a demonstration unit ( multi coloured) to show how this was built. See photos:- L motor for track drive and M motor for steeing. IMG_4123 by Doug Ridgway, on Flickr IMG_4124 by Doug Ridgway, on Flickr IMG_4125 by Doug Ridgway, on Flickr IMG_4126 by Doug Ridgway, on Flickr PS Can the moderator correct the spelling in the tile box for Caterpiller - thanks.

Thanks for making the pale grey text darker - I can read it now without straining my eyesight.

Completed track unit. With track looped around sprockets there was a gap of about 5mm, when joined tension is enough to keep the whole track in tension. IMG_4122 by Doug Ridgway, on Flickr

Using Milan’s idea # 2: I have built a track tensioning device unit for the MOC I am currently building. It also incorporates a track support sprocket. The drive spocket section will attach to this. Awaiting delivery of more grey shock absorbers with soft spring to complete the track unit for the other side. IMG_4121 by Doug Ridgway, on Flickr IMG_4120 by Doug Ridgway, on Flickr

Milan, thanks for those tips. I like the idea of a tensioning device but don't have enough of the grey shock absorbers at the moment.

Tommy, thanks for the reply. After some experimenting I have found that 20L between sprocket axles works OK for my MOC giving a sightly tensioned track which will not have any suspension with just support / guide rollers. The track speed required is very slow.

When building MOCs with caterpiller tracks I always seem to end up with the track being either too tight or too loose. Does anyone have data on the correct number of caterpiller track elements for the large and small sprocket wheels with spocket centres at various distances apart. For a new MOC I have sproket centres at 21L with large sprokets & 37 track pieces. Tried 22L apart with an extra track piece but still too loose. The black track seems better than the grey track. Should the sprocket centres be an even or odd number of holes apart ?

Both the 6542a & b grey clutch gears have only a small contact area with adjacent framing wheras the Red 18946 has a much larger contact area due to the inner and outer raised rings. Also the Red clutch gear has mouding marks on one side (the shallow deperessions at 180. degs) which might possible catch on adjacent beams causing stiction. Best to place these Red clutch gears so that the side with the depressions engages the driving ring and not facing the adjacent beams etc.