FreeRidin'

Well I'm a little short on money right now and I desperately need a new chain guide. So I was thinking I would build up a "ghetto" one that will hold me over until I have the money for a new E13. I'm think it can't be too hard... all I have to do a trace a friends boomerang and get some rollers.

This is the chain guide I was thinking of tracing...


So my question is what type of metal should I use and also what thickness? My options are hot rolled steel, aluminum, and stainless steel.

edit: Wow I can't even spell making.

cryptid01

I presume you've got an "in" with a machinist? Lucky.

Just measure it for thickness and check the materials when you trace it.

dminor 

My kind of thinker!!

I actually made my own copy of a Heim Three-guide a couple years ago (single, lower boomerang) out of stainless. I was about to build a full-on upper/lower until I got my Syncros sponsorship.

You are completely on the right track. The boomerang will be easy to fabricate. For wheels, you can use old skateboard wheels. Sandwich the wheel between two fender-washers with a carriage bolt and turn down a groove on the drill press (unless you are lucky enough to have access to a wood lathe).

I was going to use two lexan dinner plates that I bought for a couple $ each off clearance at Bed, Bath & Beyond (I think). Was going to turn the outer to size on my neighbor's metal lathe and use a drill press and router to create the inner 'star.'

Don't hesitate to PM me if you have any more specific questions. The project almost went ahead last year until I was saved from myself

FreeRidin'

No, I have a steady hand and a dremel.

FreeRidin'

Lexan plates, good idea. I'll take a trip to BB&B some time soon.

How thick were these plates though, I'm kinda skeptical that they would be strong enough.

cryptid01

Whoa, easy now! Ghetto doesn't have to be loud and ugly.

You can get a pair of the MRP rollers, including sealed cartridge bearings and mounting hardware for 20 bucks or so at your LBS. If you knock off the boomerang and bashrings well enough, there's no reason it won't perform exactly the same as the original item. And you won't need to buy an E13.

Doug, I sincerely hope you were joking about the dinner plates...

cryptid01

All I can say is good luck with the ISCG mounts, then.

dminor 

They're about 1/4+ thick right at the base (the part that sits on the table). I was going to turn away the flange from the base, which would have left me I think enough to cover a 36-38T ring.

BTW, here's a fuzzy pict of my shiftable (three-ring) guide:

dminor 

I got my skatebord wheels from the used pile a the skate shop for free (had to do some pawing to find ones with good bearings).

Hey, the dinner plates said "guranteed unbreakable" - - but probably not in bashplate use though

FreeRidin'

I figured I would just drill a total of 9 holes, in groups of 3.

nmn25

I made my own chain guide complete w/ inner and outer bashguard out of .25 inch plexiglass and an e thirteen parts tree. It actually worked. My friend made one out of carbon fiber (he has the molder and material and uses it. Mine was light and strong. Go for plexiglass!

dminor 

Just be aware that plexy shatters and is heavier than polycarbonate. That is why I suggested the Polycarb dinner plates. Freeridin', if you want, I'll send you mine, as I probably will never use them.

If you wanted to try something a bit different with the boomerang, get a piece of UHMW and make upper and lower glides out of it too. UHMW is self-lubricated, slippery and machinable. (Can you tell I've thought about this stuff waaaayyyyy to much?)

alumrock12

i remember seeing somewhere that someone made a chain guide out of a tictac box and one of those scotch rolls that they roll tape around.

FreeRidin'

Well I guess I need to decide on what material I should use to make the boomerang out of. I found this site that sells 1ftx1ft sheets of many metals in many different thicknesses.

I was thinking either 11 GA. (.120 thick) Steel Sheet or 3003 Aluminum Sheet .125 (1/8) thick or possibly some of those polycarb dinner plates...What to do, what to do??

FreeRidin'

Tape roll, ok.

Tic Tac box, ermm**********?

dminor 

I'd go with 1/8" 6061 if you can get it. 11 ga. steel will be a bit heavy - - 14 ga. would be better but will be flexy once you punch enough holes to properly lighten it. Plus, to do steel right, you really need a flaring tool to flare the holes. I did mine the hard way with a ball peen and many different sockets; but I didn't have to do many. You can make a flaring tool with a wheel stud and a lug nut though. You'll also need to brake the edges to help stiffen it.

If you go aluminum, you don't have to do anything but cut it out, dress it down and bore your holes. Another good source for small qtys of 4130 steel and aluminum is Shapiro Supply:
https://shapirosupply.com

FreeRidin'

That site I posted does sell 1/8" 6061, but the total cost + shipping comes to $35! Plus if I use MRP rollers my total cost for the project would come to about $50!! Considering I can get a new E13 for $80, this project no longer seems...right.

Dminor: If you think those plates would really work, I would be happy to take one of your hands.

dminor 

Whoa! You know it just dawned on me - - you are in the metal capital of the world just about. There must be a bazillion scrap metal yards in Chicago. Go to one and ask to paw through one of their aluminum bins. You should find many new, clean offcuts (might even fine some diamondplate - -how cool would that be?) DO NOT pay new price for small scraps of metal. [I once built a whole back-blade for my wheel tractor for about $50 in metal from the local scrap yard.] A good yard will charge you about double what they are paying for scrap, which means that a 12"x12" of 1/8" should only be about $5.

If you really want to give it a go, PM me an address and I'll send a plate. I'll even throw in an MRP roller that I found on the race course one time and threw in my spare parts stash. Good luck!

FreeRidin'

Sounds great dminor!

One more question...I asked my friend with the chain guide if it was ISCG mounted of BB mounted, it turns out it is BB mounted. I know I can easily draw in the ISCG mounts, but would it be easier to make my guide BB mounted?

I don't think I would be able to make that lip that the BB sits in, but is that really necessary? Also if I use this plate from dminor it will most likely be pretty thick and off set my BB, but that is ok because I am running a 5mm spacer that the chain guide could replace.

Through all this rambling my question is should I make my guide mount via BB or ISCG?

dminor 

Make it ISCG if you have the mounts on your frame - -it's much more secure to keep it from rotating if you clonk it on anything.

In some ways, BB mounting is more difficult to make because, as you noted, you will need to create a recess around the BB hole to cut down its thickness behind the BB flange. It CAN be done though. Best way is with an end-burr bit from your Dremel set in a drill press with the depth-stop set. Then bore down to the stop and step around your hole. It doesn't have to be perfectly round and pretty, but it does have to give clearance all the way around the BB flange. You are basically using the drill press as a very crude vertical mill.

Plate and roller going out in the U.S. Mail today. Good luck!

EDIT = Almost forgot: if you need the hole layout for ISCG, here is the standards page:
https://www.iscg.org/INTL_STD_MTG_LOCATIONS.pdf

EDIT #2 = 1/8" is only 3.175mm, so it should replace your spacer fine; no need to shave it down . But I'd still go ISCG if you can.

mx_599

FreeRidin'

I knew you would catch that.

cryptid01

Data point: The boomerang on the System 3 is 5.5mm thick.

FreeRidin'

I guess I'll update this thread as I progress.

Here's what I have so far...




Any suggestions?

dminor 

looks good. You may want to leave a little more meat in the rearward web so that your third hole is not quite so close to the edge.

There are not-too-hard ways to achieve curved slots rather than individual holes (not really necessary, but a bling factor) but they are best done on a drill press.