Help. 225mm Chassis & Body Alignment Blunder.

[kitefighter]

This is embarrassing.

I just finished building a Tamiya M-07 Chassis to 225mm wheelbase option. So far, so good. Then I tried to mount a HPI Datsun 510 body on top. And that's where the problems began.

I've somehow managed to mis-align the holes on the body to the mounting posts on the chassis. (Please see attached picture). The result is that on right turns, the wheel front nearside wheel touches and distorts the body. I really screwed up and feel lousy after all the excitement of returning to RC models for the first time since I was a boy.

A possible solution might be to fit HPI cup racer wheels and slick tyres as they might be a smaller diameter. Which would be a shame because I'm over-budget on this project and rather liked the higher profile Tamiya tyres.

The more drastic solution would be to cut a larger apeture on the wheel arches, but I'm not confident I'd mess that up.

Any help or ideas and share experiences would be welcome.

Thanks in advance.

[WillyChang]

HPI mini wheels are same std size as Tamiya, no help there. They do a proprietary MX60 wheel size too, but that's larger than mini so won't help either.

Shell needs to go rearwards a bit... slot the body holes or bend the posts with some heat maybe.

Is that for racing or just casual/display? If not track running... you can afford to remove some rear toe-in, remove the spacing washers on the arm mounts (which angle the arms forwards). Rear tyres should move back 2-3mm I'd guess.

 

[Jason1145]

Yeah when working on these M chassis cars it becomes even more important to get those body posts lines up correctly as there is so little room for error.

I now have a BMW 2002 shell that is off Centre on a M03 too

For your issue ( and if I eve revisit my bodged shell too) rather than hack that gorgeous bodyshells wheel arches ( which will stick out like a sore thumb to your knowing eye) I would look to adjust the body post holes into their correct locations with a combo of either shoe goo, New lexan off cuts or lexancircular body post hole protectors.

Somehow filling in the wrong post holes with the above and starting again.

I know the end result might not not perfect around the post holes but it might be the lesser of two evils.

 

[Tamiyabigstuff]

Have you considered magnetic body mounts ?

Should give you some adjustment on the body positioning without making more holes. 

[kitefighter]

8 hours ago, WillyChang said:

HPI mini wheels are same std size as Tamiya, no help there. They do a proprietary MX60 wheel size too, but that's larger than mini so won't help either.

Shell needs to go rearwards a bit... slot the body holes or bend the posts with some heat maybe.

Is that for racing or just casual/display? If not track running... you can afford to remove some rear toe-in, remove the spacing washers on the arm mounts (which angle the arms forwards). Rear tyres should move back 2-3mm I'd guess.

 

Thanks for the advice about the HPI wheels being the same size as the Tamiya wheels.

Your suggestion of trying to bend the body mounts is a great idea that doesn't require further tampering with the body. 

The mounts only need to be adjusted a little bit to bring the body back into alignment as you say. 

The body mounts are very hard plastic and I will have to heat them somehow to bend them. Or I could cut them and then fix them within a metal tube (like a bicycle frame). 

Someone must have done this before.

[kitefighter]

5 hours ago, Jason1145 said:

Yeah when working on these M chassis cars it becomes even more important to get those body posts lines up correctly as there is so little room for error.

I now have a BMW 2002 shell that is off Centre on a M03 too

For your issue ( and if I eve revisit my bodged shell too) rather than hack that gorgeous bodyshells wheel arches ( which will stick out like a sore thumb to your knowing eye) I would look to adjust the body post holes into their correct locations with a combo of either shoe goo, New lexan off cuts or lexancircular body post hole protectors.

Somehow filling in the wrong post holes with the above and starting again.

I know the end result might not not perfect around the post holes but it might be the lesser of two evils.

 

Thanks for advice about not cutting the wheel arches. How did you resolve the issues with your BMW body? Can you post pictures?

[kitefighter]

In did actually consider magnetic body mounts from the beginning but decided it was an RC car first and a scale model second. At the moment it's neither!

5 hours ago, Tamiyabigstuff said:

Have you considered magnetic body mounts ?

Should give you some adjustment on the body positioning without making more holes. 

 

[Jason1145]

1 hour ago, kitefighter said:

Thanks for advice about not cutting the wheel arches. How did you resolve the issues with your BMW body? Can you post pictures?

I didn’t.. it’s still skewiff... I’m scared to ruin it anymore

[Kingfisher]

Both of you should try the magnetic body mount ideas. At the very worst, you'll have holes for posts that you won't use. Sure beats wallowed out holes patched with excess lexan material. 

[markbt73]

Another option is to heat up the Lexan flare behind the front wheel and bend it out/back just a hair, so it clears...

[Jason1145]

7 hours ago, Kingfisher said:

Both of you should try the magnetic body mount ideas. At the very worst, you'll have holes for posts that you won't use. Sure beats wallowed out holes patched with excess lexan material. 

I had a hard time getting the magnetic mounts in the right place on my Cosworth shell... the magnets are so strong they have no room for adjustment once magnetised together so they have to be within 1mm of where you need them and trying to look under the shell ( painted already) to see where to glue the magnets in place is tricky.

And once glued on the shell they then obviously won’t move... I think if I try them on another shell I’d use shoe goo while it’s not set ( moveable) and then position the shell on the chassis and let it set/dry on the car in the correct position all the while magnetised to the chassis opposite magnets and hope and pray the shoe goo doesn’t smudge or get on the magnets and hold them together!

How does everyone else get the magnets in place on the body... sounds like I’m over complicating it but I did eventually get my Cossie shell just right but it was off putting doing it again.

[Badcrumble]

1 hour ago, Jason1145 said:

I had a hard time getting the magnetic mounts in the right place on my Cosworth shell... the magnets are so strong they have no room for adjustment once magnetised together so they have to be within 1mm of where you need them and trying to look under the shell ( painted already) to see where to glue the magnets in place is tricky.

And once glued on the shell they then obviously won’t move... I think if I try them on another shell I’d use shoe goo while it’s not set ( moveable) and then position the shell on the chassis and let it set/dry on the car in the correct position all the while magnetised to the chassis opposite magnets and hope and pray the shoe goo doesn’t smudge or get on the magnets and hold them together!

How does everyone else get the magnets in place on the body... sounds like I’m over complicating it but I did eventually get my Cossie shell just right but it was off putting doing it again.

I echo this from my experience with my 2002 shell. The front magnets fit but they are at an extreme angle because they latched immediately and there was no chance to reposition them. The rear set were too high so I switched to Velcro. I’ll need to trim my rear arches a smidge though. Perhaps the penalty for an HPI shell on an M03 but more likely my shoddy measuring!

Tips from experienced users would be appreciated! Could someone do a guide in the Build Tips section?

For the OP, the heating and bending body post suggestion sounds like the first step given that the body is already drilled.

[Kingfisher]

3 hours ago, Jason1145 said:

How does everyone else get the magnets in place on the body... sounds like I’m over complicating it but I did eventually get my Cossie shell just right but it was off putting doing it again.

I haven't used magnetic mounts yet, but this looks like a way I would try.

 

[Jason1145]

1 hour ago, Kingfisher said:

I haven't used magnetic mounts yet, but this looks like a way I would try.

 

Genius!!!!!!!! 

Thank you Kingfisher that is pure genius... This is the way I will do it next time.. wish I’d bothered to research this beforehand, this would have made my life so much easier... Im immediately now looking for my next shell to get the magnetic mounts treatment

[kitefighter]

Hello again and thank you for the suggestions. 

The problem with magnetic mounts is that I have already cut holes into the body for posts. 

The solution I think is best would be to somehow bend the mounting posts into the correct position for the body in alignment with the chassis.

The difficulty is, how to bend the plastic mounting posts.

If only there was some sort of adjustable elbow I could fit the mounting posts into.

Any ideas?

 

 

[kitefighter]

I'm going to try and bend the mounting posts by using my wife's hair straighteners to apply heat on a point I need to bend. I will experiment on plastic sprues first.

[Kingfisher]

19 hours ago, kitefighter said:

I'm going to try and bend the mounting posts by using my wife's hair straighteners to apply heat on a point I need to bend. I will experiment on plastic sprues first.

Make sure you wear some good running shoes. 

[kitefighter]

5 hours ago, Kingfisher said:

Make sure you wear some good running shoes. 

If she ever finds out how much I've spent on this project already, I'll need to fake my own death, dye my eyebrows, change my name to Phil Shockley and attend my own funeral in disguise.

[kitefighter]

Good news!

Using my wife's hair straightener's I managed to bend and adjust the mounting posts to bring the body back a little and onto the correct position on the chassis. I then lowered the body and now it steers and runs correctly. On the raised platform at least. Still a little more fettle to do and it will should be okay. Many thanks for all your suggestions and support!

[WillyChang]

definitely living dangerously by borrowing the Queen's gadgets  

Oooh do I spy a Seiko tunacan? 

[kitefighter]

Hahaha. You're right. As long as she doesn't browse to these forums, won't find out.

And yes, well done for spotting the Seiko Tuna can in the background.

[Frog Jumper]

 

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