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Posted (edited)

There seems to be a lot of crop sprayers lately:thumbup: so here is my WIP. It will be generic sprayer based on multiple sprayes I like, I take this pictures as reference:

GRIMAC%20J_Bargam.jpg&w=480&45548

The features i would like to implement are:

-Drive by one L motor

- 3 modes of steering with two L motors. Motor for rear axle will switch direction with PF switch operated by M motor

- Cabin on lead screw that can go up and down, operated by M motor

- Pneumatic compressor with L motor

- Pneumatic paralelogram

- Pmeumatic folding of 2 section arm

The scale is set by motorcycle wheels from BMW, approx 1:16

I love the rised wheels so I started with axles. To keep them as narrow as possible I decided to base them on worm gear so I can get each axle as high as necessary. Each axle is mounted to small turntable at top. I was surprised how stable the axles are. Since the pictures are not very good here is digital render how it works:

36662962450_4ab4d2b4ea.jpgWIP 4 by Ivan Moc, on Flickr

And preliminary chasis with four of them:

36252042173_8d1195015c_c.jpgWIP 2 by Ivan Moc, on Flickr

See the high ground clearance:

36662670700_703d03f497_c.jpgWIP 1 by Ivan Moc, on Flickr

Please note that the wheelbase is not final - it should be longer by 3 studs

The last feature I have is cabin that can go up and down on lead screw:

36252043723_89cd8ab1f6_c.jpgWIP 3 by Ivan Moc, on Flickr

 

Edited by Ivan_M
title
Posted
21 minutes ago, mocbuild101 said:

Those wheels suit it very nicely, but I think they need to closed off somehow... maybe with some dishes?

Yes I will use 8x8 tile in white or 8x8 dish, whatever will come cheaper

Posted (edited)

Honestly your self propelled speayer looks better with narrow tires than my version with CLAAS tires. :sceptic:

The only thing missing here is a suspension. All self-propelled sprayers have some kind of suspension. :wink:

Keep up with the good work :thumbup:

Edited by I_Igor
Posted
58 minutes ago, I_Igor said:

Honestly your self propelled speayer looks better with narrow tires than my version with CLAAS tires. :sceptic:

The only thing missing here is a suspension. All self-propelled sprayers have some kind of suspension. :wink:

Keep up with the good work :thumbup:

Thank you! I wouldn't say that suspension is the only missing thing, I also miss variable track width and ground clearance. I already spent more than enough time developing these without aceptable sucess so I will pass them :sceptic: I'm always amazed how suspension works on real sprayers, incredible machines..

Posted (edited)

I have managed to develope some kind of suspension which you can see here

Perhaps it could be usefull to you...

Variable width is more difficult to achieve and only with sprayers that have gray colored chassis so you can use gear rack from this years orange telehandler...container yard set if I remembered correctly

Sprayer was done with wrong colors so I've decided to took it a part and make with motocross bike tires (when I buy additional).

Edited by I_Igor
Posted

I have of course seen you thread :classic: Mine suspension was quite similar, worm gear can slide over axle so I started there but I wasn't able to stay within 2 studs width and that is deal braker for me.

Anyway, I have first design of arm:

36266258503_5b922604bf_c.jpgWIP Arm by Ivan Moc, on Flickr

I made it too long just to test the design. It is 120 studs long, so it would mean total width ~33m and such arms are always with more than 1 hinge. The flex is very low, far end is only ~2-3 studs lower. The final arm will be 90 studs long on each side, representing the smaller arms that are ~24m wide.

  • 3 weeks later...
Posted

I have a big update. I have been working on chasis and arms. I have addes L motor for drive, fake 4L engine and two L motors for steering. I have used the outer gear on small turntable at each axle to perform steering, but it proved to be too space demanding on place where I need the chasis to be narrow. So in the end I went wth 13L rack. The L motor drives worm gear -> 8t pinion and 12t bewel that moves the rack. Both axles uses the same setup. Gearing from drive motor is 8t pinion to 24t central differential and to each axle diff. The last motor I have added is M motor that runs pneumatic pump. I realized then that I'm running into some space isssues and there is no way to add motorized pneumatic valves. I may also sacrifice motorized PF switch for rear steering motor. I have micromotor that would fit, but I don't want to add such rare part because I intend to make instructions.

The last thing I have been working on are arms. Obviously the first arm was totally useless as it was waaaay too thick. I realized the arms cannot exceed 3 studs when folded. That means the folding section must fold inside the first section. The initial design was 8 studs wide at the hinge, so I had to redesign it completely, making slight compromises to structural strength but I'm very satisfied with the result.

Now the problem - the chasis as now can drive and steer but the axles are not very stable in parallel direction to each other. It means they make A shape after few turns due to small turntable tolerance. I guess this doesn't have solution, so the model will not be very playable, but the extreme ground clearance is one of the most importat feature the model has so I will keep it this way.

37220909122_f284fd1309_c.jpgWIP Arms by Ivan Moc, on Flickr

37220909022_9844c308d8_c.jpgWIP Chasis by Ivan Moc, on Flickr

36540254684_c27d9e6b93_c.jpgWIP Chasis by Ivan Moc, on Flickr

37220909252_8fa0791746_c.jpgWIP Underside by Ivan Moc, on Flickr

37220909352_f55490096a_c.jpgWIP Chasis by Ivan Moc, on Flickr
 

Posted
19 hours ago, BrickbyBrickTechnic said:

Wow, I quite like it so far. My question though, will the pneumatics be able to bend the tubing as much as it will need to (alot)?

Also, the rear structure currently looks weak. Any chance that can improve?

Thank you, the tubing is not a problem, there is only one 90° bend, there is no tubing on 2nd section of arm. The rear will be strenghten more, I just have to add tank to figure how much space and where I have.

10 hours ago, Paul Klop said:

Looks good! I really like the solution with the driving.

Do you also have the play on the wheels? (I had with the wheel hubs..)

Thank you, the play in axles is terrible :sceptic: The axles are strong in forward-backward direction and can hold a lot of weight, but they are weak in left-right direction. Driving straight is fine, but turning puts a lot of stress to them and they end in "A" shape. It is only lego, after all. You have to decide - high narrow axle like mine which is more for display or your solution (which I like, don't get me wrong) that is more playable...

9 hours ago, I_Igor said:

Nice development :thumbup:

Thank you!

Posted
1 hour ago, Ivan_M said:

Thank you, the play in axles is terrible :sceptic: The axles are strong in forward-backward direction and can hold a lot of weight, but they are weak in left-right direction. Driving straight is fine, but turning puts a lot of stress to them and they end in "A" shape. It is only lego, after all. You have to decide - high narrow axle like mine which is more for display or your solution (which I like, don't get me wrong) that is more playable...

Yes, I understand what you mean... I tried to make the wheel hubs more with axles and that workes for my. I really like your design and maybe you can reinforce it with some 5L/3L beams instead of the bush... Also a beam between the gear racks..

Just saying, I don't tried it myself :wink:

Posted

I realized I can implement variable geometry paralelogram very easily, it was only a matter of replacing 9L liftarm with pneumatic cylinder, here is video showing it in movement. It is very helpful because I can tilt it to help arms to fold. The weight of the arms puts a lot of stress to the hinge and folding wasn't smooth at all. I'm overally happy with the back and I will probably leave it as it is. Maybe a dual cylinder for tilting would be nicer, but i have only 5 of them and as you can see, all are already used.

 

Posted
1 hour ago, BrickbyBrickTechnic said:

Good idea, though I'm not sure that it makes sense. Why would a crop sprayer have it?

If you know why, please educate me :classic:

I have seen it on various sprayers, I think its main purpose is to have more spraying options - sometimes you want to spray not directly from top but from side. I'm not entirely sure tho. I really need it to help with arm folding.

 

1 hour ago, I_Igor said:

Variable geometry is nice idea, but now you have to hide this pneumatic hose spaghetti somewhere :laugh:

Yes that will be interesting, I have 4 pneumatic functions and running out of space :laugh:

Posted

Here is video showing how tilting helps with arm deploying and folding, it is necessary to work with valves quite preciselly but it works as I intended:

 

Posted
On 25-9-2017 at 10:35 PM, Ivan_M said:

Here is video showing how tilting helps with arm deploying and folding, it is necessary to work with valves quite preciselly but it works as I intended

Try to make a stop block so it cannot tilt to much.. Hope that helps :wink:

  • 4 weeks later...
Posted

It is done, I was waiting a long time for 8x8 tiles to cover wheels. As you can see from the progress the only thing that was left to do was finsh the bodywork. So the final pictures and one crappy video:

37140322263_567e519906_c.jpgIMGP5059 by Ivan Moc, on Flickr

37762283316_b0c73bb13e_c.jpgIMGP5061 by Ivan Moc, on Flickr

37762282676_8e241499a0_c.jpgIMGP5062 by Ivan Moc, on Flickr

37100695494_ca06251bfa_c.jpgIMGP5063 by Ivan Moc, on Flickr

37762281946_df7ec797ae_c.jpgIMGP5064 by Ivan Moc, on Flickr

37100694994_8d13ee5eed_c.jpgIMGP5065 by Ivan Moc, on Flickr

37762281196_7ed2f14285_c.jpgIMGP5066 by Ivan Moc, on Flickr

37552331010_c13c79c29f_c.jpgIMGP5070 by Ivan Moc, on Flickr

23957714298_4588553b45_c.jpgIMGP5071 by Ivan Moc, on Flickr

37552329840_c80306af56_c.jpgIMGP5074 by Ivan Moc, on Flickr

 

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