I am told to be legal you need suspension so I don't think making it like the original gun would be legal anyway these days.
Without a reasonable suspension the real ones could have shaken apart as soon as you towed them.
It is a tricky engineering problem to solve. The assembly need to have give in transit you don't shake bits off or out of alignment (like your sights, or recoil buffers!), yet when deployed, is rigid enough to aim accurately and strong enough to handle the recoil forces, yet light enough to be manhandled (then someone asks can you make it elevate higher so we can get more range, and can we have about 15 degrees more left/right for tracking moving targets! 
) I think the Royal artillery went through 3 different carriages for the 18 pdr between the wars before finding one that solved all the problems well enough. Then they able to adopt the 25 pdr due to re-armament 
I think the American ones used torsion bar suspension like the German Gun (they did have one to look at), opening the split trail legs locked the suspension in place so the whole assembly became rigid. You will notice that the hub centers don't quite line up with the axel, that is because of the the swing radius of the arms.
To the tune of "Mademoiselle from Armentières"
Napoleons army ran away, As you do
The guard stood firm for Frances Pride, As you do
They said the guard will stand and die
But we heard what their Colonel cried
It wasn't pretty I tell you.
Resistance is fertile
Yes it does have a torsion bar suspension system hence it has 2 tubes close to each other that are not obvious from many photos.
The wheels are mounted on the front tube and the gun onto the back from what I can make out, I am trying to work out if I can copy the system and make my own axles but for now I think the way I will do it will be with indespension type units for ease.
You can also see this gun has a recoil damping system.
Taken from here http://svsm.org/albums/37mm_m3a1/
Free speech is expensive these days!
I have just spoted these that would look good and a great price but a bit far for me to get to LITTLEHAMPTON, West Sussex 
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT
Free speech is expensive these days!
I have just spoted these that would look good and a great price but a bit far for me to get to LITTLEHAMPTON, West Sussex
Half the price!
http://cgi.ebay.co.uk/LAND-ROVER-MILITARY-TWO-WHEELS-TYRES-/330505574955
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
I have just spoted these that would look good and a great price but a bit far for me to get to LITTLEHAMPTON, West Sussex
Half the price!
http://cgi.ebay.co.uk/LAND-ROVER-MILITARY-TWO-WHEELS-TYRES-/330505574955
Yes same guy but
TWO LAND ROVER WHEELS FITTED WITH 7.50 x 16 TYRES ( tread very low ! NOT road legal)AS PER PHOTOS.
I just bought the other 2 and am trying to sort out transport, I am also after a Sankey axle with hubs.
A mate of mine said fit one of these in it 
http://cgi.ebay.co.uk/Bird-Scarers-Gas- ... 3363124b1b
Free speech is expensive these days!
This is the idea at the moment as I have wheels and hubs on the way.
I suspect the indespension units will have to fit on the load member rather than the way I have drawn it here.
Free speech is expensive these days!
Should the wheel separation be the same as the jeep?
If it was, the wheels would follow in the jeep's tracks off-road.
Should the wheel separation be the same as the jeep?
If it was, the wheels would follow in the jeep's tracks off-road.
I will keep that in mind when I start thanks for the idea, yes the original would be made that way. My jeep is a few inches narrower so I will take that into account.
I think the indespension idea should work or I could make a torsion bar system with some thought, one problem could be that it may sag on one side if the indespension units become un-balanced.
EDIT
If you want a fun read take a look here 
http://www.turbosport.co.uk/showthread. ... birdscarer
Nice clip here 
http://www.youtube.com/watch?v=4WRpjeeH8rw
Free speech is expensive these days!
A friend of mine is also just about to start on an M3 here is a Pak 36 he made.
[youtube2]GmydcNcPqNY[/youtube2]
Free speech is expensive these days!
I have been staring at the photos I have on here and it does look like this gun doesn't have suspension as I first thought, if you look at the tow arm ends at the point were they connect to the gun you will see they have a extension which passes over the front pipe axle so stopping any vertical travel.
I have a friend that made the original German version about 10 years ago, and I remember him telling me that when the US copied the gun they left the suspension out of the design 
So they bounce like hell!
I will see what I can cheat into the design.
I have also been working out how to make fake traverse gearboxes to give the 17 degrees of left to right movement of the gun and shield.
I came up with 2 ideas to do it on the cheap.
Idea one involved 2 universal joints but I gave that up for idea 2.
Obviously the real one would have a worm roller I would think but this should do the job ok.
This looks better 
Free speech is expensive these days!
You could use a chain pulley mech' to traverse the gun, in the same way a traction engines front steering is designed.
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
You could use a chain pulley mech' to traverse the gun, in the same way a traction engines front steering is designed.
Good idea but I think it would need to be locked when towing or it would swing depending on the gearing I suppose. I had a word with my friend in the North West with the pack and he used car ring gears and cut them up then just used the gear of a starter motor to crank it.
I was a bit impetuous yesterday and bought 2 myford hand wheels but I suspect 88mm Di are a bit small.
It's just that the guy had a matched pair for £23 and I do need 2 the same.
Maybe I should have gone for these at 122mm Di but they look a bit plastic, but maybe if I burnt the coating off they would work.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0261152371
EDIT just rang them they are all plastic no metal inside 
Free speech is expensive these days!
Yeah, ideally you're looking for hand wheels around the 180mm dia' mark. The one I was offing you came off of an old milling machine! 
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
Yeah, ideally you're looking for hand wheels around the 180mm dia' mark. The one I was offing you came off of an old milling machine!
Maybe it would be ok with 2 odd sizes anyway if you are still ok with me having it.
When you look at the various pictures on the net some have the wheel on the traverse and some on the elevation they mix them about.
Free speech is expensive these days!
Here's the hand-wheel I have. Any use to you?
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
Wow that's a monster in comparison any idea on the kg?
It does look more to scale if you look at the shield the distance from the left to the scope slot is 12" and the slot depth is 4" I think.
I probably wouldn't need the pinion gear to save postage.
Free speech is expensive these days!
Wow that's a monster in comparison...
It's 185mm dia. & 25mm thick.
...any idea on the kg?
3.75kg in it's current state.
I probably wouldn't need the pinion gear to save postage.
Only thing is, I haven't any 'large tools' here in Oxford. No gas torch to fee up the nut on the axle (the central nutted axle has a thread on t'other end which can be rigidly mounted, but this means I have no anchor point which which to turn the nut off of it's thread, as it'll just spin in relation to the handle... )
A Proud Member Of 'Team Spleen!' who play mainly at Gunman Airsoft, Tuddenham, Suffolk.
Only thing is, I haven't any 'large tools' here in Oxford. No gas torch to fee up the nut on the axle (the central nutted axle has a thread on t'other end which can be rigidly mounted, but this means I have no anchor point which which to turn the nut off of it's thread, as it'll just spin in relation to the handle...
Ok mate I have loads to do for now so will get back to you when I get to that point.
My wheels with bar grips are here and the lathe hand wheels which do look nice, maybe the gun didn't have space to have both hand wheels at 5" so they only have one or the other depending on preference elevation or traverse.
My shield is cut but I was re-checking and I have it 30mm too tall so have to decide whether to cut it off the nice galvanised top or the complicated shape bottom
Either way it looks a wet weekend to do this in the garden with my angle grinder.
I have some 250kg suspension units on the way + some hubs that should be here by now.
These suspension units should fit inside some 2" box section, so if I use box instead of scaffold for the load baring cross member I should be able to hide them in the ends.
These units are in a 40mm box casing were as the 350kg and 500kg are in 50mm box so posed a problem.
I am still not sure the best way to fix the stub end down to the front scaffold pipe axle, if I mount it using the stub axle on a swivel the axle may move in an odd way, maybe the answer is to just weld it to the scaffold or cut the stub axle off and slide it into a hole cut in the scaffold then weld it for strength.
Olf,jgOBMUqpzecY!~~_12.JPG)
Option A looks the best but would be a pig to have to take apart later if I had to.
Option B would strip down but would need some limit on movement at the axle fixing.
Maybe the answer is weld box section to the scaffold and slide the suspension arm into that then bolt through it 
Free speech is expensive these days!
My wheels with bar grips are here and the lathe hand wheels which do look nice, maybe the gun didn't have space to have both hand wheels at 5" so they only have one or the other depending on preference elevation or traverse.
From the pictures, it looks like it might be movable from one to the other.
My shield is cut but I was re-checking and I have it 30mm too tall so have to decide whether to cut it off the nice galvanised top or the complicated shape bottom
Why not just leave it as-is? Is anyone going to notice it's 30mm too high?
Alternatively, put a dummy weld line 30mm from the top and say it was a field mod.
I am still not sure the best way to fix the stub end down to the front scaffold pipe axle, if I mount it using the stub axle on a swivel the axle may move in an odd way, maybe the answer is to just weld it to the scaffold or cut the stub axle off and slide it into a hole cut in the scaffold then weld it for strength.
How was the German one done?
My wheels with bar grips are here and the lathe hand wheels which do look nice, maybe the gun didn't have space to have both hand wheels at 5" so they only have one or the other depending on preference elevation or traverse.
From the pictures, it looks like it might be movable from one to the other.
My shield is cut but I was re-checking and I have it 30mm too tall so have to decide whether to cut it off the nice galvanised top or the complicated shape bottom
Why not just leave it as-is? Is anyone going to notice it's 30mm too high?
Alternatively, put a dummy weld line 30mm from the top and say it was a field mod.I am still not sure the best way to fix the stub end down to the front scaffold pipe axle, if I mount it using the stub axle on a swivel the axle may move in an odd way, maybe the answer is to just weld it to the scaffold or cut the stub axle off and slide it into a hole cut in the scaffold then weld it for strength.
How was the German one done?
Yes as you say the hand wheels can go on either traverse or elavation as I say maybe they didn't have space for large wheels on both.
I am tempted to leave it 30mm high and god knows I have a number of other points that will be a compromise to make this work.
The German gun used torsion bars but the yanks didn't use any suspension, I am looking for a picture of the German system to link in.
EDIT here is one but not how I expected it to look, I expected a torsion bar but this looks like the units I am using but in an older design. 
More here http://svsm.org/gallery/37mm_pak-35-36/IMGP5322
Free speech is expensive these days!
