Gravely in drop loop frame issue

[AttackCadillac]

Hi I am fairly new to this site and i'm on my first build. My problem is that I am trying to blueprint a drop loop for the engine to cradle in and I can't find a good way to do it. If any of you have had this problem before I could really use some help.

P.S. I REALLY do not want to take the engine apart to make a cutout of it.

 

[Russell]

I was unable to open the picture. What model gravely are you using as I have a gravely that I'd like to use myself. I have built several drop loop frames (see my photos) in the past. Please repost the pic as I am very interested in this project.


http://motorbicycling.com/attachment.php?attachmentid=78301&stc=1&d=1433201281

 

[Gbrebes]

When you mention blueprinting I already feel out of my league, but I built/modified my own drop loop frame, so I figured I'd offer advice. If you have the engine, I would lay it on its side on some cardboard and sketch out a line that your frame will follow. However, I would also recommend figuring out your drive set up and pedal clearance.

Will you be running a jackshaft? If so, most people locate it in front of the seat post tube, so you may need to locate your engine more forward towards the front wheel than you would think. Also, if you are running bike pedals, you will need to ensure that the pedals will clear the engine, transmission components, and exhaust.

When I was building my frame, I made a life-size drawing of the frame, wheels, and bottom bracket location. It was very helpful in planning.

But you mention blueprinting, so maybe you are doing a CAD drawing? In which case you would just need engine dimensions.

Hope that helped a little,

Gilbert

 

[curtisfox]

You could also make one out of wire first and then have one bent the same...........Curt

 

[AttackCadillac]

Sorry to take so long replying. The engine is from a Gravely model L (different from the one pictured by Russell). If you click on the picture it should pull up (never tried putting a picture on a forum before so experiencing technical difficulties :/ ). In response to Gbrebes; I may have used some poor wording when I said blueprinting, what i mean is i need a way to trace the engine relative to the frame without laying it on it's side because the engine has too many splines and stuff sticking out of it to lay it flat (hence me saying I didn't want to take it apart). I am not running a jackshaft I am running pedals. the only problem i see is the placement of the Magneto. Finally in response to Curtis fox; I have considered using wire but I cant think of away to get it to retain it's shape after forming it to the frame.

 

[racie35]

Go buy a length of brake line tubing....carefully form it to what you need,holding it up to the bike allowing for bigger diameter when done....take that to where ever you're bending your tubing and copy. Both nipples left on your frame now are probably at the wrong angles.

 

[racie35]

Looks like the rear one you need to extend down at the seat tube angle...then loop. The front you can probably cheat on a little to make it look like something.

 

[Velodrome]

The pic opened for me... ( Roy Scheider ) WERE GONNA NEED A BIGGER BOAT! I've always loved the look of those motors but seeing it next to that frame really shows how big it is. I'll be watching this one!

 

[wret]

As Gbrebes said above, a full scale drawing of your frame and a cardboard cut-out of the motor will help.

You might want to consider a keystone style mount.

 

[AttackCadillac]

OK, thanks for all the help everyone. Im going to change my plans a little bit and run the loop into the bottom of the petal knuckle instead of the front (A little more work, but more traditional). I'm going to do a full build thread When I am done, but I will be checking back Whenever I run into problems. Hopefully I can do the Gravely build everyone has been waiting for!

 

[curtisfox]

That is one big motor you will need lots of gussets at all joints..........Curt

 

[AttackCadillac]

OK, so I think i've got it! What I ended up doing was taking a conduit bender and bending some conduit to the shape I need. Now I just need to take a quick trip to my pipe bender to have the good stuff bent to the right shape using the conduit as a reference. I hope this helps anyone in the future who runs into this problem.

 

[silverbear]

I hope you'll do a build thread as you go instead of waiting until you're done. Wrong turns can be as informative as all of the right turns and it is fun to take part in the thinking things through process. Is that a Worksman frame? Straight bar Schwinn? Welcome to the forum, by the way.
SB

 

[curtisfox]

SB is right as some of the members are full of good helper ideas,as you already found out about the loop bending................Curt

 

[racie35]

Post a pic of your template

 

[AttackCadillac]

Here is the template I made.

I'm waiting to do a build thread until i'm done because this build has been a long slow process. I'll stop for months at a time and then pick it back up again when i get some free time. I dont want to leave anyone hanging so it's going to be one big "shabang" when i'm done.
To answer a few questions; It's a stretched Worksman frame (4 inch) with a L model Gravely 5 horse, I built the wheels myself with a Sturmy Archer drum hub in the front and a Chinese hub in the back with a drum brake and a freewheel on the engine driven side, all tied together with 12 gauge spokes.

Here is the mock up loop with the frame (yes the engine is only being supported by wire, I'm crazy like that).


P.S. Thanks for welcoming me to the forum Silverbear!

 

[butchl]

I can't see it. ??

 

[AttackCadillac]

Sorry butchl I'm really new to this stuff. Try clicking on the pictures and they should pull open. I've tried a few different image hosting places and I keep having these problems :/

 

[racie35]

I can't see the pics either

 

[butchl]

It really sounds interesting.