1st Crawler - MFM Build - 'lorra Pics!

[petrolhead]

Hi all on RCC. I've been admiring some of the creations on here for aaages, so thought it was about time I tried my hand at the crawling scene. I've been into R/C since I was about 10 and now 6 years later, I'm still into it :lol:

Anyway, this is the build thread of my MFM Chassis'd kinda scale kinda not scale crawler. I've done the write up on another forum where I'm very active but don't think it's fully appreciated to it's full value over there, so I've copied it over to here, if that's alright. If anyone's got any hints/tips/guidance for me, seeing as I'm a newbie to this scene, they please feel free to add it. Here goes -

First decision was that it would be TLT size, rather than clod, as this should keep costs down.
Did a bit of research and with the help of Twinset from Tamiyaclub.com I came across a chassis that seemed to be just what I was after, the MFM Racing Scale Chassis. This had just the right balance of scale-ness that I was after. So I ordered that and a few other key parts - Moabs, RPM Revolver Narrow Rims, the MFM tranny mount plate, a high torque servo, some ball-ends and a few other bits and bobs from The Crawler Store, who I can't fault. Delivery was pretty quick and got here in time for Xmas seeing as it came all the way across the pond. I also bought 2 TLT axles, complete with 'bling' and a brand new Stampede gearbox from Mr_Pushrod, also off Tamiyaclub.com, cheers Alan!

So set to building on boxing day. First thing I had to do was lock the diff in the 'Pede tranny. I found THIS WAY to be by far the best, kudos to whoever thought of it.

Next job was the fit the MFM Tranny Mount Plate onto the Stampede gearbox. The plate has 4 counter-sunk holes which line up with 4 holes in the gearbox. However, there was a raised bit on each side of the 4 holes meaning the 4 screws wouldn't reach and the hole either side of the plate to mount it to the chassis was blocked. I could have moved the plate down so the top two holes were mounted in the bottom two, but this meant the gear box was up too high and it wasn't mounted as securely. So, out came the hacksaw and I cut off the raised bits. I wouldn't need this so it was no big deal. You can see in the pictures the parts I have cut off.

The plate finally mounted securely, after cutting:

In my opinion, the 'box is still too high but it can't go any lower as it will rub on the chassis, so I'll have to live with it and maybe stick some lead or BBs in the tyres!
Next up was mounting it to the chassis. This was no problem, just bolted it on with 2 M4 size bolts. However, when I came to put on the two middle cylindrical chassis braces, one of them wouldn't quite work in the place it is meant to as it would catch on the driveshaft. So I simply moved it along to another hole.

Correct brace mounting:

Different position brace mounting:

Motor wise, for the time being I'm using the Graupner Speed 600 I used in my XC chassis trail rig. This has great torque, even better with the added torque ring.

Next up was locking the steering on one of the axles. I did this by using two ball ends, one connected to the steering and one attached to the axle and joined them together. I did this by cutting the head off an M3 screw and screwing it into both of them. This saved me tapping out both ball ends and using some M4 studding.

That done, I put the wheels and tyres on, minus the foam

Here's a mock-up shot of what it should roughly look like when done. What I'm waiting on now are shocks and the Traxxas slider driveshafts.

Read on...

 

[petrolhead]

Next batch -

I got the body from ModelsportUK here in England, a Proline Chevy C10, meaning I could set the wheelbase and ground clearance and get on with making the links.

To do that I used Twinset's great how-to guide on Tamiyaclub and most helpful it was. First thing to do though was to relocate the link mounts from underneath the axle to the vertical face. This meant, however, I had to take off the axles braces that the axles had on already. This involved undoing 24 nuts and bolts, gripping the bolt with pliers in one hand and turning the bolt with a screwdriver in the other, not a fun process.

Anyway, those off I put the link mounts in their new position. This meant a little of of axle-shaving was needed as there was a ridge in between the two bolt holes. So out came the files and 5 minutes later it was sorted. With link mounts in their new position I could measure how long I wanted to make the links. First pair for the rear axle turned out a bit long, no worries I thought, I'll make the front ones a bit shorter by the same amount. The front pair turned out a bit long too, so I had to go back and cut them down a bit. Now the rear links are a bit longer than the front, no biggie.

I also moved the front steering link to above the knuckle, for better approach angle. And I got rid of those pointless bumpers.

Here are the pics. The chassis won't be as high up as it is seen here obviously, but the phone was handy and wasn't too far off the final height. Took me a while to get the chassis balanced on it, and when I did, the phone rang :lol: Obviously the body will be raised up off the tyres too, only after it's undergone some major lexan surgery.

 

[petrolhead]

Final lot for the time being -

The shocks are Traxxas T/E-maxx ones, got them for the bargain price of £10 inc P+P off eBay, brand new for 4.

First up the new rear shock and link mounting position. This little bracket does both in one, whereas I was using 2 seperate brackets before. I've now got a couple spare to play around with. The rear shock mounting was pretty simple, although they do rub on the tyres still when at full flex.

The front shock mounting was more tricky. I couldn't mount them anywhere outside of the chassis as I'd get major rubbage when flexing whether the steering was turned or not. And even when not flexed they rubbed a bit. So I had to mount them inside the chassis. Unfortunately the springs catch on the edge of the rails a bit, but I can't push them in towards the middle any more. If anyone's got a better solution I'd love to hear it.

Still, it works pretty well at the moment. This is without the final links attached, though.

And the pics of the body hackage - I went all out on the back but need to do a bit more on the front. I brought the sides up too, it looked silly with them hanging lower.

Obviosuly the body will be higher and at a flatter angle, I haven't got round to doing the mounts yet.

Right now I'm STILL waiting on the slider shafts from ModelsportUK, had them on order since before Xmas, and some great link/servo mount plates are on their way to me as we speak, from Twinset.

I'm sure some of you are looking on in horror at some of the ways I've done things, if so, let me know with your suggestions, like I said earlier.

I hope you don't mind me triple posting, I thought it would all be too much to comprehend in one post.

Couple of things - first, I need some way to make the axles a bit wider / get the wheels to stick out a bit further. I can't simply user a widener as the axles only have a few threads for the nut as it is, so if the wheels were any further out at all then the nut wouldn't have anything to grab onto. I've heard Blackfoot axles are meant to be a bit longer - yes,no?

And finally, but most importantly, IT NEEDS A NAME!

 

[gopher]

there is a sticky about widening options... it has good information available! the blackfoot option seems to work, but I have read more people using other fabrications out there.

the build up looks good so far, can't wait to see the final product.

 

[balang_479]

Really nice work... so clean. BTW awesome snap shots....

 

[Dragon51]

Very nice rig some people just don't get it. How fast dose it type question may be 5mph what can you make it go faster. And you spent how much people!

 

[petrolhead]

Ok so pretty much done now, all I need to finish it off is to paint the bod. Anyway - last few build up shots here...

Thanks to Twinset from Tamiyaclub.com for the servo/link mount plates, they're super. Also got the sliders from Modelsport, meaning I could get on with making the upper links.

As I had the driveshafts, one thing I noticed was that, as I couldn't run any caster on the front axle due to the fact it would mess the steering up, then there would be some horrid driveshaft angles. So I swapped the links around, now I've got the longer ones at the front and shorter ones at the rear. Means the front axles a bit further forward = better weight distribution = good! So I made up the links, running a good bit of caster on the shorter spaces rear axle to get a better 'shaft angle, and no caster on the front but it doesn't need it.

Twinset's plate:

Once that was done, all I had to do was extend one driveshaft...

... and bung the eleccies in. I struggled to find somewhere to mount them low down where all the wires reached so I settle for a temp solution of mounting them in a tray up top. Very pleased with the servo too - it'll turn the wheels whilst not moving on carpet with ease, nice!

So here we are - final shots before paint goes on. And, of course, the obligatory flex shots, and there's plenty of that too. It's doing 6 batts in the pic but will do 7 although does rub on the body slightly (which I've hacked away at even more):

I've given it a quick run inside and am very pleased with the way it performs, better than I expected. It's still a bit top heavy for my liking but I'll sort that out another point.

And one for luck -

 

[lunchbox]

Looks great, I like it. That rear lockout cross bar will catch on everything though, I did mine the same way. I finaly got some lockouts from The Crawler Store and fixed it after I got annoyed enough. Too bad that electronics tray wont fit between the frame sides, it looks perfect. I guess you could add spacers and widen the frame just enough so it fits, that may even let you lower the trans one more notch too.

 

[balang_479]

Are the chassis plates just too close to mount any tranny sideways?

 

[wallaz]

I managed to get my trans to sit lower but it took a bit of dremel work to get it there. I thought they had modified the mount not long after.

Heres a picture of it in place

Any questions and I'll try to answer them.

Here's the build I did as well

http://www.rccrawler.com/forum/showthread.php?t=61196&highlight=WALLAZ

 

[1981toyotapu]

I didnt read this, but wow that rear axles is on a HORRIBLE angle, shorten the upper links.
Looks good other than that for a first build.

 

[RCMFMaxxMan]

I didnt read this, but wow that rear axles is on a HORRIBLE angle, shorten the upper links.
Looks good other than that for a first build.

that angle is fine. look at how steep the shaft is. the angle between the pinion and the shaft looks about zero degrees so the angle is at the minimum.

The rig looks good but since you have the rear axle rotated so much you should lock the rear steering in a different manner because that link is going to hang up.

 

[balang_479]

I agree with Toyotapu, the rear driveshaft angle is obsurd, you should try and reduce it and still make the drivetrain efficient.

 

[petrolhead]

The reason I've got the axle on the angle like that is to make the driveshaft angle better, which is what I've done. If I shorten the upper links the axle will be flatter but the drive shaft angle will be worse. I've got the best possible angle I can of the shaft to the rear axle with the current lower link set up.

Like MaxxMan said it's the angle between the axle and the pinion that counts and that angle's pretty minimal.

The only way to make it better would be to make the rear lower links a bit longer and shorten the fronts, but I don't need to. As I'm only using 2WS not 4 then it doesn't make a difference at what angle I'm running the rear axle.

I understand what you've said about the rear steering arm catching so I've got rid of it and locked the rear steering differently.

Anyway, got it finished and painted it up, here are the final pics:

 

[RCMFMaxxMan]

looks like a very capable setup you've got going. good work. what camera are you using? the photography is top notch.

 

[petrolhead]

Thanks MaxxMan! It's a Canon EOS10D, but you know what they say, the photographer takes the pictures, not the camera :lol:

 

[lunchbox]

the photographer takes the pictures, not the camera :lol:

Yeah, my wife says the same thing, but she always grabs her Nikon D200 when she shoots weddings, and only uses the Powershot S2 IS when she might fall of the horse... which makes me wonder about that saying.

 

[red jim]

I am slowly replacing all of my stampede transmissions with ax10 transmissions,they are way smaller and lighter,something to think about

 

[BigKRI]

Looks good
i really like the wheels