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I did a short video today that illustrates how the Cheapskate bearing should behave when the eccentric cams are properly adjusted.

http://www.youtube.com/watch?v=5LCHGMiv ... 8SUMXjPBZQ

For the curious, the machine in the video is tentatively named "Blue Max" and is painted in the same colors used by many Link Trainers (flight simulators) in the 40's and 50's.

g.

Thanks for the tip... was just looking for something like this as mine tend to loosen up over time and wasn't 100% sure what the proper tension was supposed to be. Seem like they need to be just right or they bind/slip.
Is there a good way to test with the belts still installed? As they were a pain in the A** to get in.

Once you've got them properly adjusted, they're pretty easy to keep that way. Just check them for abnormal movement as part of your daily start-up routine and tweak as required.

That being said, I've got over 170 hours on the Cheapskates installed on Orange Menace and they're still properly adjusted. Just keep an eye on them and be careful with the adjustment of the bearing on the back of the Cheapskate - that can add a TON of friction with very little turn of the adjustment screws.

The test where I show applying side force to the 'skate will work the same whether or not the belts are installed.

g.

I usually roll the carrier up and down while I hold one of the bearing covers to see if it slips or grips the rail. If the bearing tends to roll more than it tends to slip, I call that good enough. Check a top one, a bottom one, and the side bearing, and you've got yourself one zero lash cheapskate assembly.

I check this each day before I start printing. It's quick and easy, and it gives you a good idea of when it's time to service your machine and tighten up other things that may have moved over time. (mine tends to need maintenance more often because I haul it in the car to go to a Makerspace every week)

I'd like to modify the Cheapskate to use a spring (like the EZ Struder spring) to tension the rollers. This way it should never need adjustment. Keep the eccentric cam, just tension them with a spring.

PartDaddy wrote:I'd like to modify the Cheapskate to use a spring (like the EZ Struder spring) to tension the rollers. This way it should never need adjustment. Keep the eccentric cam, just tension them with a spring.

That sounds like a great idea PartDaddy!

Found the reason why my kept coming loose... it wasn't the cam, it was actually the nuts in the back were a little looser than they should have been. I know this might be going overboard but in the mean time it would be nice if the doc included torque specs for the cheapskates.

The word "tighten" isn't vague.

g.

If you don't give specifications how am I going to know what to set my calibrated torque wrench at! *sigh* If there's a standard we use it at my work (even when it's absurdly applied like calibrated torque values on electrical connections ).

And the word tighten might not be vague, but the point just before it becomes overtighten is...

Unless of course tighten means, tighten until the melamine begins to indent (or makes a cracking noise) and then back off slightly. Not that I did that or anything...

lordbinky wrote:If you don't give specifications how am I going to know what to set my calibrated torque wrench at! *sigh* If there's a standard we use it at my work (even when it's absurdly applied like calibrated torque values on electrical connections ).

And the word tighten might not be vague, but the point just before it becomes overtighten is...

Unless of course tighten means, tighten until the melamine begins to indent (or makes a cracking noise) and then back off slightly. Not that I did that or anything...

Specification: Tighten until screw breaks in half, remove broken screw, insert new screw, tighten a little less than the first time.

Touchy feely, no torque wrench... If you're using the 5th bearing, keep it completely loose, slide the cheapskate up the t-slot while adjusting the eccentric cams. Keep a finger (and thumb, or all thumbs) on the bearings while sliding. When there's friction, test the backlash by twisting the carriage a little. Then snug the 5th bearing in a similar fashion. BTW, good video geneb.

The video was definitely helpful, I've gone back a couple times and reduced the cheapskate tightness down as I push the speeds higher. Occasionally I've gotten better at removing twist with less firm adjustments (or the parts have broken in a little, but i'd like to think i've continued to grow).

geneb wrote:I did a short video today that illustrates how the Cheapskate bearing should behave when the eccentric cams are properly adjusted.

http://www.youtube.com/watch?v=5LCHGMiv ... 8SUMXjPBZQ

For the curious, the machine in the video is tentatively named "Blue Max" and is painted in the same colors used by many Link Trainers (flight simulators) in the 40's and 50's.

g.

Oh I see that easy star a hanging on the wall back there mister!

Build and fly that sky walker now, do it, just do it, you know you want to.

Dude, I'm so backed up on stuff I need to get done, I'll get the last project finished 10 years after I've died.

g.

Hey guys Im just wondering should there be no side to side play on the cheapskate at all?? Or is it alright if the cheapstake has a very slight bit of movement from side to side. And when I say slight movement I mean when you try to push it from front to back it moves the width of a hair horizontally

I may just be very paranoid from adjusting these cheapskates and sanding down the ujoints for so long but I want to make sure these are installed properly before moving onto the belts.

The least you can manage without binding is best.

No side to side motion at all.

g.

No motion AT ALL! GOT IT!

Guess its time to get back to adjusting the cams.. again......

Thanks guys

Once you get the technique down on one, it goes pretty quick. Having them loose can adversely effect print quality.

g.

***USE THIS VIDEO AS A EXAMPLE OF HOW THE ROSTOCK MAX CHEAPSKATES SHOULD BE ASSEMBLED.****

http://www.youtube.com/watch?v=5LCHGMiv ... 8SUMXjPBZQ

*** DO NOT USE THE VIDEOS BELOW BECAUSE THEY MAY BE INCORRECT****

Hey geneb,

Here's a video of my cheapskate's vertical test. Excuse the music in the background. http://www.youtube.com/watch?v=aPESUGhi3z0
I think that my assembly is pretty good. It has little to no friction and all the bearings move at the same speed.

Here's a video of the cheapskate as i try to push and pull it horizontally. I dont know if you can see it but is that too much side to side play?? Again sorry for back ground music.
http://www.youtube.com/watch?v=_QtjkzdyVV8

I know you said "NO MOVEMENT AT ALL" But if i tighten the screws for the axel supports even the slightest bit the cheapskate glues itself to the tower.
Should I keep adjusting or is that okay??

You don't want any side to side play.

Adjust the two eccentric cams such that when you're pressing against the opposite side of the Cheapskate, the bearings on the eccentric cam side turn when you move the Cheapskate up and down on the rail. That should be tight enough to give you the "fall speed" you see in both my and your videos and it should all but eliminate any play. Any remaining play in the Cheapskate should go away when you tighten down the bearing that holds the "back" of the tower extrusion. Just don't tighten it so much that it grabs the tower like a drowning man. It's a very fine line to walk, but once you've got one adjusted, you'll know what to look for and the other two will be a lot easier.

g.

Thank you Obi-Wan

Now Im off to other forum posts to figure out the belt tension.

Without this forum I think my rostock would have spontaneously combusted a lloonngg time ago.

I realize I'm tooting my own horn here (HA!), but if your printer is working well enough to get usable parts, these will make getting your belts uniformly tight super easy: http://www.thingiverse.com/thing:146815

Hey edward,

Thanks for the advice. I actually came across this thing while trying to find solutions to the cheapskate, belt problems.

I also came across this new cover for the bearing.
http://www.thingiverse.com/make:38593

I think another problem that I can see alot of people coming across is getting the belt to be completely centered on the bearings. Ive read situations where the belts were chewed up due to the belt onto being centered. Maybe these will help a bit.

kit wrote:Hey edward,

Thanks for the advice. I actually came across this thing while trying to find solutions to the cheapskate, belt problems.

I also came across this new cover for the bearing.
http://www.thingiverse.com/make:38593

I think another problem that I can see alot of people coming across is getting the belt to be completely centered on the bearings. Ive read situations where the belts were chewed up due to the belt onto being centered. Maybe these will help a bit.

I don't see a download link for the http://www.thingiverse.com/make:38593

Eaglezsoar wrote:

kit wrote:Hey edward,

Thanks for the advice. I actually came across this thing while trying to find solutions to the cheapskate, belt problems.

I also came across this new cover for the bearing.
http://www.thingiverse.com/make:38593

I think another problem that I can see alot of people coming across is getting the belt to be completely centered on the bearings. Ive read situations where the belts were chewed up due to the belt onto being centered. Maybe these will help a bit.

I don't see a download link for the http://www.thingiverse.com/make:38593

Collected!

Eagle: the link is for someone's "Make." You have to click on the picture of the original item on the right.