Different versions of model B?

[Cyclist2]

I also put a wood arm on mine to extend the monitor.

Very cool, what are the arms fixed to on the cage?

I took a 8" length of 1 x 3 wood, drilled the right sized holes through the 3" width at each end, trimmed as necessary and then just bolted it to the bracket on the erg at one end, and the monitor on the other end. Using a drill press makes it easier to get the holes through the width straighter.

https://imgur.com/i2BFafN

[johnlvs2run]

The wood arm was attached to the wire frame by the pressure of the t-bolts and nuts.

I used three 1x3's and 4 t-bolts, nuts and washers to attach to the cage.
The inside 1x3 was as long as possible while still being able to fit inside of the cage.
The outside 1x3 was a similar length, and the middle 1x3 was long enough to accommodate the length that I wanted.

The t-nut holes were spaced between the wire frame, as shown in the photo.
I marked the inside length first, used a hand drill for the holes, and knocked in the t-nuts.
Then I inserted the inside length and gradually added the other pieces, while tightening and adjusting the position.

[msaspence]

This is definitely an improvement I will make after I've got it up and running.

Thanks guys

[msaspence]

I got it up and running today finally!

I didn't manage to get the larger sprocket off, so I'm just running with the smaller sprocket for now (although the larger one does still run pretty well). I'm hoping that I can get a model b axel from Concept UK but they don't sell them online and they are not taking orders over the phone at the minute. Failing that I may angle grind it off but am scared of damaging the axle underneath.




I also jerry rigged the PM arm, thanks to johnlvs2run and Cyclist2 for the inspiration



One problem that plagued me once I get it back together was the two arms were pinching in on the ends of the axle and making it stick, especially on the return. So I added this block of wood to wedge them apart and it runs great now.



I dinged up the paint work pretty bad due the pinching of the arms and the tight fit so I still have some patching up to do. I'm also hoping to get the wood wedge and the PM arm machined in steel, I know there are places online that will do it but I'm not sure at what cost. If it's too much I will at least get these timber bits painted up.

Oh and I need a new chain guide, hoping that this is also something that I can order over the phone, but if not I might have a bash at getting one 3d printed.

[Cyclist2]

Nice job! I find restoration work like this very satisfying, and you now really "own" that erg.

I've rowed my Model B more in the last 10 days than in the last 10 years, with the virus lock down in place. It's in my garage and I can wheel it outside in the driveway to row in the fresh air and sunlight. You gave me the inspiration to get it cleaned up, lube the chain, install new batteries, and get back on it.

Looks like you might have a small patio where you could get it out, also. Enjoy your "new" erg!

[c2jonw]

Looks great- I love seeing the older machines still in use.

Regarding the issue of the arms pinching the axle, there's a better solution to that. Looking at the 4 large main frame bolts that attach the footplates and arms to the monorail, if you loosen the top forward nut and bolt a bit and tighten the rearmost bottom nut and bolt the arms will come apart. I'd suggest removing your block of wood and doing this procedure with the four 1/2" flywheel screws loosened enough to tell when the arms are the appropriate distance apart. I'd suggest having the arms 1'4" wider than the flywheel assembly so the cage halves are under just a little tension. JonW

[johnlvs2run]

Msaspence, good for you getting it going.
One additional thing you could do with the arm would be to center the monitor.

[msaspence]

Regarding the issue of the arms pinching the axle, there's a better solution to that. Looking at the 4 large main frame bolts that attach the footplates and arms to the monorail, if you loosen the top forward nut and bolt a bit and tighten the rearmost bottom nut and bolt the arms will come apart. I'd suggest removing your block of wood and doing this procedure with the four 1/2" flywheel screws loosened enough to tell when the arms are the appropriate distance apart. I'd suggest having the arms 1'4" wider than the flywheel assembly so the cage halves are under just a little tension. JonW

You are indeed right, and I have adjusted said bolts. However I'm keeping the wood block in place, unless you have another solution up you sleeve for this... When I pull on the chain the arms and fly wheel assembly roll to the right quite badly. I don't know if that is normal for a model A/B or something else that needs tweaking. The wooden block seems to add enough stiffness between the left and right arm to dampen the affect significantly.

One additional thing you could do with the arm would be to center the monitor.

Between the screen being offset to the left on the monitor and my make shift arm veering quite a bit to the left this is intentional.

[c2jonw]

When I pull on the chain the arms and fly wheel assembly roll to the right quite badly. I don't know if that is normal for a model A/B or something else that needs tweaking. The wooden block seems to add enough stiffness between the left and right arm to dampen the affect significantly.

Not sure if you're describing normal flexing/movement or if there is something wrong. Can you post a video?

[msaspence]

Sure...

https://s3-eu-west-1.amazonaws.com/msas ... G_5546.mov

[msaspence]

I wanted to replace the bearings, they (and that large sprocket) are the only moving parts left to swap out. I didn't think they were available but I just wasn't looking hard enough they are totally listed in the correct part of the online store.

I don't see a replacement part for the bearing clutch in the fly wheel though. I found a comment on another post that Carl made that there isn't any benefit to doing this (except I guess maybe some noise reduction), since it is static for the pull and any resistance on the recovery is just added to the drag factor. Is this correct?

Also thinking about it... if drag factor is calculated on the recovery how does changing the sprocket affect the drag factor?

[c2jonw]

When I pull on the chain the arms and fly wheel assembly roll to the right quite badly. I don't know if that is normal for a model A/B or something else that needs tweaking. The wooden block seems to add enough stiffness between the left and right arm to dampen the affect significantly.

I don't see anything abnormal going on in the video, but if you like the block in place it isn't going to do any harm.

If the clutch is working I wouldn't replace it. You might consider cleaning and lubing it- WD40 or equivalent solvent to clean, then some 20 weight oil or very light grease to lube it, being careful not to dislodge any of the needles.

Drag factor calculations would take clutch drag into account, and are not affected by sprocket size. Good luck with it....Jon

[msaspence]

I don't see anything abnormal going on in the video, but if you like the block in place it isn't going to do any harm.

If the clutch is working I wouldn't replace it. You might consider cleaning and lubing it- WD40 or equivalent solvent to clean, then some 20 weight oil or very light grease to lube it, being careful not to dislodge any of the needles.

Drag factor calculations would take clutch drag into account, and are not affected by sprocket size. Good luck with it....Jon

Good to know thank you

[TennFishin]

I wonder if anyone has tried attaching the monitor arm part from the Model C to the mounting bracket, much like the wooden extension you made? The part number is 1025.
https://shop.concept2.com/726-large_def ... -black.jpg