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View Full Version : Any of you guys have to drill through the frame?



Lionstrike
13 January 2011, 1925
So I think I might have to rework my motor mount idea. I have friends that can weld and machine and were willing to help, but I am not sure that they share my enthusiasm for this thing. It's possible that I might have to fly solo at some point.

I don't know if anybody has looked, but around here gas in 3.25 a gallon. It's getting out of hand. That REALLY fuels my desire to give big oil the finger.

So I was thinking about these right here:
http://www.robotcombat.com/products/DCW-ETEK50.html

or... the mount here:

http://www.teamdelta.com/products/prod5c.htm

But I only have ONE motor mount hole that's already there. ....I'd have to drill through the frame.

Anybody ever have to do that? John Bidwell does it in one of his books I believe. Doesn't that weaken the frame? Does it make it harder to get registered/insure?

Inquiring minds want to know :)

Thanks.

DaveAK
13 January 2011, 1942
$3.25/gal? What's wrong with that? We pump oil out the ground here and we're paying $3.80/gal. But that, as they say, is another story. :)

What bike are you working on again? Can you post a picture? Any chance of welding on a lug instead of drilling a hole? Fabricating some kind of something?

Tony Coiro
13 January 2011, 1955
Take a couple pictures of the frame from different angles. There are a ton of ways to do something but generally only one really good way. I welded mine onto the swingarm on my first bike, I wouldn't want to do it again, bolts are much easier IMO.

teddillard
14 January 2011, 0413
Sorry, nope.

I did drill some places in my frame but they were not structural, they were just spots where I needed to mount relatively lightweight stuff that exerted no force on the frame. The motor mount will exert force, and lots of it, in a few directions. Not only do you not want to drill holes in a frame in convenient places to mount the motor (which may not be particularly strong to start with), but any place you hang that motor has to be reinforced to take the added stresses.

We just happened to be talking about that at the bottom of this page: http://www.elmoto.net/showthread.php?615-Vintage-Cafe-RD350/page5

The motor mount points on the frame are probably pretty strong, enough for adapting to your motor, but that doesn't mean a random point on the frame is, or could be, and drilling it will make it weaker.

On an aside, does that supplier really have the actual Etek motors for sale? I thought they were relatively unavailable at this point. Did you contact them to verify availability? (i can haz ETEK?)

EVcycle
14 January 2011, 0446
"This Product Has Been Discontinued" but they do carry the Mars Brushless.

Nice looking mount.

teddillard
14 January 2011, 0450
Weird, where did you get that message? I even added it to the cart, no mention of not being available...

"We have a quantity of these available for immediate shipment, all new in the box. "

Lionstrike
14 January 2011, 0750
I got my ETEK original on ebay. They had a bunch of them a while back and I got it for $275 shipped. I don't think that they have ETEK originals on that site, but if you can get them on ebay, you can usually have them for a song.

So... no love for drilling through the frame huh? O.k. That's cool. I saw a picture in "Secrets of El Ninja" where Bidwell made a mount that he drilled through the frame for... I really don't want to do that.

I'll put some pictures up in just a sec.

Lionstrike
14 January 2011, 0802
I got my ETEK original on ebay. They had a bunch of them a while back and I got it for $275 shipped. I don't think that they have ETEK originals on that site, but if you can get them on ebay, you can usually have them for a song.

So... no love for drilling through the frame huh? O.k. That's cool. I saw a picture in "Secrets of El Ninja" where Bidwell made a mount that he drilled through the frame for... I really don't want to do that.

I'll put some pictures up in just a sec.

Here they are:
http://www.personal.psu.edu/cer143/EV/img_0065.jpg
http://www.personal.psu.edu/cer143/EV/img_0066.jpg
http://www.personal.psu.edu/cer143/EV/img_0067.jpg
http://www.personal.psu.edu/cer143/EV/img_0068.jpg
http://www.personal.psu.edu/cer143/EV/img_0070.jpg
http://www.personal.psu.edu/cer143/EV/img_0071.jpg

But to be honest I am fairly in love with the idea the Ted had here:
http://sphotos.ak.fbcdn.net/hphotos-ak-snc6/hs047.snc6/167699_1851660690772_1218396040_32215008_8238693_n .jpg

How it it secured to the top? Welded to the swing bar assembly?

Lionstrike
14 January 2011, 0809
By the way, I was considering this:
http://www.personal.psu.edu/cer143/EV/mountidea.jpeg

What the photos do not show is that there are two motor mount holes near the front of the frame. I could in theory use the three holes marked with red Xs to make a motor mount plate and go from there.

So... nobody is feeling that Etek motor mount from Robot Marketplace? I was thinking of buying it... if nothing else, it would help if I have to take it to a machinist and match up bolt holes.

teddillard
14 January 2011, 0826
This thread is more or less a step-by-step-
http://www.elmoto.net/showthread.php?615-Vintage-Cafe-RD350/page4

...but it bolts to the frame using the same mounts that the original motor used. Here:

http://evmc2.files.wordpress.com/2010/12/picture-42.png?w=640&h=431

Lionstrike
14 January 2011, 0841
That's a darned fine looking motor mount.

Problem is... I don't have that top hole to screw the mount into, which is why I considered drilling into the frame.

Rats.... back to the drawing board.

Say... what about some JB weld? Yeah?

teddillard
14 January 2011, 0852
You need to have mounts welded to the frame properly. End of story... sorry. :( (...and thanks!)

Lionstrike
14 January 2011, 0911
Sooooo maybe that ETEK motor mount from robot marketplace is a good idea?

Or this?

http://www.personal.psu.edu/cer143/EV/mountidea.jpeg

Nuts & Volts
14 January 2011, 0923
I drilled through my frame. I can upload a picture tomorrow. I did it in 4 places for battery mounts. I drilled through steel square tube in all cases. The upper mount is not fully loaded with weight it just prevents the upper batteries from sagging.

The lower mount doesnt take all the weight either, it is supporting the batteries from underneath.
All the holes go straight through the frame and they are sized to fit an M6 easily. I drilled as close to center on them as well. I have had no issues with it so far. I think that drilling through the frame is a case by case basis.

Pictures tonight should make it more clear
-Kyle

teddillard
14 January 2011, 0927
Battery mounting is not the same as the motor mount. You're not holding (relatively) dead weight, you're applying all sorts of angular force. Sorry, this should be done right, no two ways about it.

Lionstrike
14 January 2011, 0929
I drilled through my frame. I can upload a picture tomorrow. I did it in 4 places for battery mounts. I drilled through steel square tube in all cases. The upper mount is not fully loaded with weight it just prevents the upper batteries from sagging.

The lower mount doesnt take all the weight either, it is supporting the batteries from underneath.
All the holes go straight through the frame and they are sized to fit an M6 easily. I drilled as close to center on them as well. I have had no issues with it so far. I think that drilling through the frame is a case by case basis.

Pictures tonight should make it more clear
-Kyle

But you didn't drill through the frame for the motor mount though right?
(Really considering that ETEK motor mount for sale)

sparky_mark
14 January 2011, 1011
As and when I get round to actually building a bike, I'll use a method like Teds but extend the motor plate forwards to attach to the original front ICE mount. This will make the motor plate very rigid, which it needs to be as it will be coping with around 12Hp from a Mars motor. Cutting into or drilling through the frame is a big no-no unless you really know what you are doing, especially if your frame is aluminium.

Lionstrike
14 January 2011, 1014
So I take it nobody is really on this drilling through the frame for a motor mount. I can see that.

Can anybody tell me why buying that Robotmarketplace mount would be a horrible waste of money? Otherwise... I might just get one. It'd at least give me more ideas for mount positions.

teddillard
14 January 2011, 1053
Well, because I can guarantee it won't match up with but one hole on your frame, and the cost of getting a mount that is exactly what you need is around $80 - $100 for milling or waterjetting from your design. Assuming you have to mount using one existing hole, then place another mount somewhere on the frame that can take the stress, it's not going to match up to the stock mount.

Nuts & Volts
14 January 2011, 1116
Agreed that you should NOT drill through the frame for a motor mount, unless you reinforce the area AND know what you are doing (ie minor force analysis on area).

I think you should weld tabs to the frame to which you can bolt in a plate motor mount.

Lionstrike
14 January 2011, 1118
So... I am sensing a lot of

NO!!!!

O.k. then... let's re-examine the concept of the swing arm mount shall we? How's about I use that robotmarketplace mount, drill into the swing arm and mount it there?

I presume that drilling into the swing arm is considered to be o.k.

teddillard
14 January 2011, 1125
I presume that drilling into the swing arm is considered to be o.k.

I do believe you've located the one place on the bike that would be worse to drill into than the frame. Oh, the tires, that's a bad idea too... yeah. :D

What you could do is to fashion some sort of bolt-on connection for your frame, if you really have no way to get something welded on. You know, like a clamp or something...

Lionstrike
14 January 2011, 1141
Whoa... I can't drill into the swing arm either? No0o0o00o

The reason why I asked is because I saw a ton of swing arm mounts on EV album and Bidwell even used it as an example in "Secrets of El Ninja" (which is more theory than step-by-step application).

Clamps sound good.... but also getting that plate mount also sounds good. Here's why I am being a knucklehead about that mount.

1) It's got the bolt pattern that I need. If I need to have a machinist do up a custom mount, I know exactly where to put the holes and exactly of what dimension they need to be.

2)I think my welder friend might just have a welder and an angle grinder. That's it. No water jetting or anything fancy like that, so no 1.25inch routed hole at the center of the mount so I can use all of the bolt holes.

So any way I go... we're going to need an Etek mount (which as I understand is a standard bolt pattern that I could put other motors on later if I wanted. Even if I wanted to have plate steel bolted in to the original bolt pattern.... still going to need the Etek mount.

I think I should just get it. I spent the same amount of $$$ on the Tyco EVAAANA contactor. It's not a big deal.

Nuts & Volts
14 January 2011, 1214
You dont need a CNC for make a mount. I used a drill press, big ass bits, lots of oil for lube, and an air dremel to "mill" out a hole big enough for the mount shaft. I drilled the other motor bolt holes as well. And this was on 1/4" steel which was a PIA but took about 3-4 hours. 1/4" is as i see now just overkill.

So
1.) Have your friend weld on a tab or two.
2.) Buy a piece of aluminum (like teds).
3.) Mark the frame hole/tab bolt patterns
4.) Mark the motor shaft hole (line it up with swingarm pivot and wheel center)
5.) Mark the motor bolt holes from the shaft center (use a drawing to make measurements)
6.) Drill the holes, (small bits to large bits)
7.) Dremel or mill the shaft hole to fit
8.) Bolt on
9.) Go fast

Cheap, simple tools, little bit of labor, simple design

teddillard
14 January 2011, 1218
or, bigbluesaw. http://www.bigbluesaw.com/saw/

Lionstrike
14 January 2011, 1220
Too late :) I already bought the robot marketplace mount.

...And to tell you the truth, I feel a lot better about it now. The extra $$$ doesn't bother me. Right now, I've got one MAJOR thing on my bucket list. Just one. If I for whatever unforseen reason died tomorrow without doing this, it'd be the ONE thing in my life I'd really regret...

Just once... I want to ride past the gas station on my EV and give big oil the finger. One time. That'd be good enough for me. F$%@#* you big oil. I am not buying your environmentally polluting, expensive crap anymore.

If this $65 shipped helps IN ANY WAY to get me there.... I call that money well spent.

Lionstrike
14 January 2011, 1221
Oh, and please pardon my profanity. Some things just set me off.

Lionstrike
14 January 2011, 1316
WOW.

Bigbluesaw looks AWESOME. Thanks man!