Newbie Scratch Build - D575A Dozer

[skeeter]

Excellent progress is being made, & it looks great, ESPECIALLY for a first build!

[Lil Giants]

Premacon sells a hydraulic pump & valve block that many ppl have bought before. https://shop.premacon.com/index.php?cPath=35 The pump/motor originates from this guy https://www.modellhydraulik.com/ though I'm not sure if the rotatory valves are exclusive from Premacon or not.

[sparkycuda]

Wow! Excellent work - details of tracks are really great, so I'm sure the rest of the machine will be exceptional.

Ken

[Originalrob]

Originally Posted by Lil Giants

Premacon sells a hydraulic pump & valve block that many ppl have bought before. https://shop.premacon.com/index.php?cPath=35 The pump/motor originates from this guy https://www.modellhydraulik.com/ though I'm not sure if the rotatory valves are exclusive from Premacon or not.

Yes these are the ones I’ll be looking at getting when the time arrives. I’m not sure if I need to go for the 5mm fittings or the standard small 3mm yet or to have one value each for the front lift cylinders. Lots of thinking and work to do before then ! Was working on the tracks this weekend but I think I made a boo boo as the pads are now too close and rub so will have to order some more metal and rebend.
Thanks for a the kind comments so far
Rob

[Jared]

Looks like your track pads are on the right track In post #19, I was looking at the angle of the bends and the grouser bar fit thinking that'll bind up as soon as they get some dirt/rocks/sand in them but I see you've made some adjustments and they look real good now.

[Originalrob]

Few pics of things that are happening:

Experimenting with the track rollers:









These have come out really well and run nice and smooth. plus they add a lot of weight

Track guides bolted together temporarily before welding together and milling to shape:

[crueby]

Great looking track parts, very well done!

[Originalrob]

thanks Chris 👍🏻
It’s slowly getting into a functioning shape but I need to start focusing on finishing off everything and then start adding all the details that I want. I can see why some of these models take hundreds if not thousands of hours to complete. I guess when it finally moves a bit of dirt around it makes it all the more worth it !
Oh and the steel splinters 🤦🏼‍♂️
Rob

[Originalrob]

Hi All

Hope everyone is safe and well !

Its been a wee while since I last posted any updates but I have been busy honing my skills and completing parts that just take ages (undercarriage).

I have nearly completed one side and making fast progress on the other now that I know how it all works !

enjoy the update pics:

[Originalrob]

[Originalrob]

Sorry about the photo bombing didn't realise I had done that many !







working on the transmission and making good progress so fingers crossed I can get it moving under it own steam soon

Rob

[kerst]

Beautiful work!

Kerst

[egronvold]

This is pretty awesome (and I can appreciate the hours spent before each picture could be taken).

[Hemi1966]

Excellent work !

[avel]

The more photos the better! I also enjoy text. I love reading about how people make their own models and how they get around/solve problems along the way.

[Originalrob]

Originally Posted by avel

The more photos the better! I also enjoy text. I love reading about how people make their own models and how they get around/solve problems along the way.

Yes totally agree ! and if I remember correctly it was a reason I started my own thread - to share my learning experience so I will keep true to this and add in my limited experience in this terrific hobby

Today I was adding in some details to the drive sprockets and fixing details:















The drive and transmission has been the most time sapping process to date. as I am not of a engineering background this has taken maybe far longer than it should have. Although there are a few very amazing scratch builds on this forum there wasn't enough details to help me make a knowledgeable decision in my build. So this is what I have gone with :

24v motors https://gimsonrobotics.co.uk/categor...d-24v-versions

1:2 reduction bevel gears to make right angle transition

Linear and thrust bearing on the internal shaft + locking nut

Tapered roller bearing in the hub/sprocket to sort out both axial and radial loads?

I will post some pics of the setup this week to illustrate

more details to follow

[Originalrob]

Mind dump incoming !

from my limited experience these are the following things I have learned that have made the most difference:

Get a DRO ! - its all about making parts that are repeatable ! this makes it so much easier ( CNC is the next step maybe one day)

Get quality tools if you can - you have probably heard this so many times before and I can attest buying a £20 M2 tap is far better than one that costs £2 ( trust me the cheap one will break on the first few holes whereas the other will just carry on for hundreds)

Be methodical - making repeatable parts means cleaning between parts , resetting dials, taking your time. don't take short cuts.

Design before any fabrication - as I am going along I actually wish I would have drawn everything up in Fusion 360 before I started. you can waste so much time re-centring / setting up parts that could be done in one .

Vinegar cleans all the mill scale and heat (soldering) blackening off metal you could ever need ! ( Bio Carb soda stops the process). I wish I knew tis from the first day. clean stock metal is very helpful when making repeatable parts.

I am still figuring out the rest !

Rob

[ThunderTruck]

As someone who has never tried to build anything like what is found on these forums I find myself coming back everyday for updates and to admire the talent and ingenuity (and zero drama). Thank-you for sharing.

[Azonic]

Very nice work, looks beautiful!

[Originalrob]

Hi Everyone

its been ages since i have updated my progress on the dozer but its been a crazy year and progress has been patchy.

This is basically where i have got to since the summer:



Almost ready for a test run in the dirt ! Cant wait to see it actually move by itself !
( blade and ripper still in progress)

The main time consuming work were making the second track and all the under carriage elements. Not really worth posting as its just a replica of what i had already made and extremely boring !

What can be seen in the image above at the moment weighs in at 40 kg (88lbs) and with the ripper and blade/hydro pump etc should be about 50 - 55 kg in total. I may try and see if i can rig up a makeshift blade to see how the traction works.

So going back to where i left off, i had some issues with making a right angle gearbox and initially when with this:



The gear box, axle and drive train have taken a lot of working out and time as i could not really tell if i was on the right track ( not from an engineering background) and i was worried ( still am a little bit ) that the whole things might chew it self apart.

after several trials with f