Warrior MCRV - FV513 - Build Update

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AndyR
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Post by AndyR » Wed May 04, 2005 10:34 pm

Rob,

I do have a budget, and so far I'm sticking to it. I reckon that the running gear will take approx 70 to 80% of the final cost of the vehicle.

The rapid prototypes are not too expensive but not too cheap either, but the good thing is you can get a couple made each month. Just think of it as a very large Airfix kit where each month you design some more intricate parts and then get them made. I'm in no hurry so I can afford to take my time and spread my costs of a year or three.

Also doing it this way provides excellent 3d CAD experience, which is where the future lies (I think).

Cheers
Andy R.

Fabrice

Post by Fabrice » Thu May 05, 2005 10:29 am

Andy,

Great stuff!

I can see from your previous CAD renders that you appear to have a pair of Parvalux type integrated motor/gearboxes in the nose section. The only problem with these units can be the right angled output shaft, as opposed to the inline drive shaft of, say, a Como type unit. Basically the units can be a bit bulky to squeeze into an AFVs forward section. I assume this is why you are contemplating a chain drive?

If it is getting a bit tight, you might consider using a right angle drill attachment with its output shaft passing through the final drive housing to the sprocket. The casings of these adapters generally have solid mounting points for side handles. Greenweld have one for £12.99, your local DIY shop may have them to cheaper. Either way they are half the price of the dedicated right angle units from RS. This would require a rethink of your Parvalux motors; the simplest option being to mount them transversely one behind the other, bit like the modern 1/16th Tam gear boxes, and to fabricate one long and one short drive shaft.

One additional benefit is that universal joints (including shock absorbing types) can be mounted between the adapter and the gearbox proper giving protection and some latitude as to the mounting position of the motors.

Chain drive is perfectly feasible, but does add complexity to the construction and maintainance of the model. I know as I am designing a chain driven winch for my own model!

Given a choice. I would always use a shaft driven design. I am sure others will disagree!

Cheers
Fabrice

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AndyR
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Post by AndyR » Thu May 05, 2005 12:14 pm

Fabrice,

Thanks for your response, I like what your thinking, I'll need to investigate this one further. At the moment using a chain drive limits the gearing due to the maximum size of sprocket I can get into the main drive hub, and also the clearance of the chain working inside the hub is an issue. I was intending to use 3/8" duplex chain as this seemed to suit my estimated power requirements.

The parvalux motors are the PM-60 type, the same as what Amourtek uses,on there Tiger tank. I think what I really need to do now is sit down and do some calcs and work out how much power I need to move the model up a 45degree slope (I know roughly what the max weight will be now) from this I should be able to work out the torque required and then to correctly spec out the motors. I selected this motor about 6 months ago and didn't give it any real thought other than it turned the output drive through 90 degrees (a requirement at the time) and had been proven on other models.

I had hoped to use the Iljak gearboxes, coupled with either a petrol engine or one electric motor, but I'm waiting to see how the chaps in the states get on with there metal / alloy T-34. I'm slightly concerend the g/box might not be strong enough for a tank that weighs approx 80kg (my all in target weight).

Incedently this leads to another question, I have been quoted to get the track links cast in brass, this being heavier could become a very expensive issue for the motors. Anybody got any ideas on this?

Let me know what you reckon.

Cheers
Andy R

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AndyR
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Post by AndyR » Thu May 05, 2005 1:08 pm

Fabrice,

Can you post me the link to that greenweld gearbox please, I've just been looking for the gearbox you described but I can't find it.

Many thanks for your help mate!

Cheers
AndyR

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Chieftain 900
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Post by Chieftain 900 » Fri May 06, 2005 8:08 am

Andy

Think I may have mentioned it in our conversasions but when I did my first set of tracks for the Conq brass was an option I thought but having tried the weight and cost never went that way and used lost wax for the Conq and RPM mould for Sultan and Chieftain.

Like you I have opted for chain drive and find no problem with ratios. i fitted the best size i could into Conq and with one motor it was away so the 2 motors will be more than adequte to move a all metal 1/8 tank with plenty in reserve for the odd emergency.
Bob G

Heavy cav rules

http://www.Isallt.com

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Chieftain 900
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Post by Chieftain 900 » Fri May 06, 2005 8:09 am

Andy

Think I may have mentioned it in our conversasions but when I did my first set of tracks for the Conq brass was an option I thought but having tried the weight and cost never went that way and used lost wax for the Conq and RPM mould for Sultan and Chieftain.

Like you I have opted for chain drive and find no problem with ratios. i fitted the best size i could into Conq and with one motor it was away so the 2 motors will be more than adequte to move a all metal 1/8 tank with plenty in reserve for the odd emergency.
Bob G

Heavy cav rules

http://www.Isallt.com

Fabrice

Post by Fabrice » Fri May 06, 2005 10:08 am

Hi Andy,
The Greeenweld link is http://www.greenweld.co.uk/cgi-bin/sh00 ... 33#aTL9733

Very short ! Not! Or Just type in "Drill" into search field and look for '3/8" Right Angle Drill Attachment'. £12.99

For cost comparison, the small RS L-box drives are £25+, but the bigger ones are four times that. However the larger ones can be ordered with a 2:1 reduction, which might be handy.

Whilst designing a miniature chain-driven final drive in the hub would be an interesting challenge, I think it might be a rod for your own back. The final drive is the most stressed part of a tank's drive system, subject to a barrage of torsional, axial and shock loads. Most of the Panther tanks at Kursk broke down because of final drive transmission failure!

Keep it simple, build it strong!
Cheers
Fabrice

mickfitz

Post by mickfitz » Fri May 06, 2005 6:21 pm

Andy

Tis looking awsome mate ... the detail is incredible.

One question please. Where do you get those long thin nuts n bolts for the track links?

Mick

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AndyR
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Post by AndyR » Fri May 06, 2005 9:23 pm

Mickfitz,

I got a 3mm rod of stainless steel from Ondrives (i think it was a £5 for a meter) however I have found that RS does 15 meters for £15, so I know where I'll be heading next. I just cut a 3mm thread into each end and pressed the whole rod through, then used 3mm nylocs (Ondrives). The one thing i have noticed though is that the fit might be too good, ie it might be prone to jamming when working, so I may end up using 2.5mm rod, not sure on that one, I'll need to have a think about it!

Hows your project coming along? Got any pics to show, would good to see some I for one need the inspiration (as I'm a lazy sod). I might be able to help you with some of the details of the 432, let me know what details your needing and i'll see what I can do (I have a half decent picutre library), can't promise anything but it would be bad manners not to at least offer.

Have you had a look at Plain Military, usually good pics there?

http://plain-military.tripod.com/

Bob,

Yeah you did mention it mate, I did remember I'm going have a long hard think about the tracks, after all I'm not in a rush and they can even be the last thing added, I might try and give you a buzz over the next few weeks to refresh my memory, if ok with you.

Fabrice,

Got it!! Thanks, I'm not overly convinced yet (at this stage) that chain drive won't work, I think it should be ok, I have done some calcs to select the right chain (these are all stated at the back of the HPC gears hand-book, very handy). I have also just receievd Iliya's latest gearbox design, it is fantastic and I think it has punted my Parvalux motors ideas well into touch....... Petrol for me!!!!

I'll think about it some more and I'll let you guys know what my selection is. at the moment I'm about 6 months away from having any of this stuff close to moving under its own power :lol: :lol: :lol:

Speak to all you chaps later!

Cheers
Andy R

mickfitz

Thanks for the info

Post by mickfitz » Sun May 08, 2005 8:10 pm

Andy

The 432 is still at the planning/learning stage mate. I will post some piccies etc when I know what the hell I'm doing :lol:

Thanks for the 432 link ... I'm getting a nice collection of piccies now and it's a huge help. What I really need is to get my hands on a 432 and a tape measure ... most the measurements I've preened from the web are 'basic' and not detailed enough ... if only I had measured the bloody things when I worked on em for years :)

Those nuts. Do you have a part number/ID? I've looked at the website but I don't understand their descriptions :oops:

Mick

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AndyR
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Post by AndyR » Sun May 08, 2005 8:41 pm

Mickfritz,

The nylock nuts were stainless steel andcost 7p each (I bought 60), the part no:

NIN-3

The 3mm stainless steel shaft cost me £5.71, and was to H6 tolerence (2.992mm). part no:

GR2.992-6

P&P was about £4.

I think you could get these cheaper from RS, especially if you were to turn up at the trade counter (no P&P).

Let me know what dimsensions for the 432 you need, and I'll see if I can help.

A good suggestion is to contact Accurate Armour and buy a 432 1/35th scale model, get a good vernier guage and a set of calipers and start measuring. The name really does say it all............. link attached below.

http://www.accurate-armour.com/

http://www.accurate-armour.com/showaapr ... category=5

I have spoken to the owners (last year) and they get access to the real vehicles and drawings, so you can believe they are Accurate.

Unfortunatly they won't give you a copy of the drawings as they have signed some sort of non disclosure contract (bugger, yes I tried).

Hope this is of some help/interest.
Cheers
Andy R

Edited:

Forgot to mention that you should register with the ondrives website and get your self a catalouge, makes life a HELL of a lot easier looking at pictures instead of part nos :lol: :lol:

If they don't send you a catalogue (some companies are like that), re-send the form but with a fake company name sauch as Warrior Components or Boget and Scarper 8) .

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AndyR
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Re: Warrior MCRV - FV513 - Build Update

Post by AndyR » Sun Jun 12, 2005 2:21 pm

Hi,

Just thought I would post some pics of my prototype suspension, these work in a very similar fashion to the Armortek Tiger suspension.

I chose the torsion bar design after talking to another engineer at work, we discussed the pros and cons and we ended up agreeing that the best suspension to go for is the Torsion Bar design. Assuming you do grind a flat onto the rod to allow the cap screws something to key up against.

My design differs to the Armortek version by having the support and the anchor point for the torsion bar all on the same brass block. I understand the Armortek version is different, probably due to the hole spacing and cheaper to manufacture.

My suspension block design has mainly been driven due to the actual Warrior suspension design, this meant that I could not manufacture two separate blocks but one larger one accept the hole spacings.

My prototype design has failed in one key area......

The offside suspension arms and shafts must have a LH thread so that they tighten up when moved and not slacken as they do at present!!!!

I also need to get the swing arms cast, hopefully I'll be placing an order to get these done over the next couple of weeks.

Image

Image

Image

Image

Hope you enjoy, and as always constructive criticism is always welcomed!!

Does anyone know where I can get LH taps and Dies? I'm looking for M10 x 1.5 any help would be appreciated.

EDITED I have found that RS does them but they are not cheap, if anyone can advise on a cheaper alternative please let me know.
Bob,

Sorry I didn't return your call but I have been so busy, what with building a nursery for the soon to be Baby Robb (our first child), work and various Uni exams.

I will try and give you a shout sometime in the next couple of weeks....

Cheers
Andy R
Last edited by AndyR on Sun Jul 10, 2011 11:34 pm, edited 1 time in total.

Fabrice

Re: Warrior MCRV - FV513 - Build Update

Post by Fabrice » Thu Jun 16, 2005 11:27 am

Hi Andy,

Very nice progress. Are you going to calculate the all-up-weight to pre-twist the torsion bars or are you going to grind the flats and lock the anchorpoint last of all by trial and error?

You could try Tracy Tools Ltd, Dartmouth, Devon 01803833134 (http://www.TracyTools.com) for the LH tap and die.

Good luck with that nursery!

Cheers
Fabrice

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AndyR
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Re: Warrior MCRV - FV513 - Build Update

Post by AndyR » Thu Jun 16, 2005 12:09 pm

Fabrice,

Thanks for the lead. I reckon I will give it a bash and calc out the amount of pre-twist, I didn't bother for the prototype as I just wanted to test the concept. Also another thing i won't get the pins drilled for the M4 capscrews until I have the swingarms screwed in tight, as if i have them all predrilled and tapped potentially the capscrews could clash with the hull floor.

I have the swing arms being cast starting monday next week with an Aluminium and brass prototype to be sent up to me for testing before i place a final order, after that I'll be doing some small remedial maching to get them how i want them, ie 6 of them need to have a LH M10 x 1.5 thread. I noticed that RS do an M10 LH tap set for £26!!!!

Anyway will post progress tonight hopefully of the master pattern rapid prototypes.

Cheers
Andy r

EDITEDJust phone Tracy tools, £6 per carbon steel tap, or £12 for HSS tap - Cheap.

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AndyR
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Re: Warrior MCRV - FV513 - Build Update

Post by AndyR » Thu Jun 16, 2005 9:14 pm

Alright!

Got a couple of more pics relating to my master patterns for the casting order!

1 x Swing arm - damped version

1 x Hub - Roadwheel

Image

Image

Image

These are 1.5% oversize to account for shrinkage of the final parts. they also have only depressions where the holes should be, this is because I want to drill and tap the holes post casting.

Please let me know what you think.

Cheers
Last edited by AndyR on Sun Jul 10, 2011 11:36 pm, edited 1 time in total.

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