Put 2X4 under one side and lean it on the 2X4 to put a 2X4 under the other side. Go back and forth until it is off the ground.

 

Used something like this for many, many years. Of course mine was homemade but worked well.

 

As long as you secure the bike somehow.
Any time you put it on a jack or lift you stand a chance or it falling over (ya I know it won't happen to ME)...
That is what my riding buddy said to (only time he has ever dropped his Harley {except when he got in a fight with a Hyundai).
As for the jack's they sell, have you looked at some of the Japanese car jacks (starting back in the 80's)?
They are normally $5 at the junk yard, if you take just a little time you can find the right one.
I have one that slides right down the rails of my Kendon lift, works great.

As for working on your bike on the ground..... the older you get the less appealing it is and the better investment a jack or lift is.

 

I screwed two of these into the back wall of my garage. Near the floor, and 4' apart (into studs).

Center the front wheel against the wall between them, and cinch down with ratchet straps, keeping the bike vertical. Then use your scissor jack to lift the rear. Safe, and secure.

 

I have one of those, it is very stable lifting my Sportsters. But I have to put a couple 1"x2"x8" wood spacers on either side of the jiffy stand.

I also have one of the Harbor Freight motorcycle lifts:

https://www.harborfreight.com/1500-l...ift-61632.html

$89, find one of HF's 20% off coupons or wait for them to go on sale.

As others have said, a motorcycle jack or lift will pay for itself very quickly.

 

jsjacks.com

 

i never have understood why one would spend Thousands $ on a Harley and be too cheap to purchase a suitable motorcycle jack or lift if you are doing your own maintenance. The right tool for the right job philosophy.

And yes, I own a J&S jack

 

Titan lift table $1k....and a small scissor jack=$100. .....set for life !!!! Sportster= $9k Isn't it worth it to be safe ??

 

That be cool if I actually had a place for a lift table. But I do have the scissor jack

 

If you're having trouble getting the rear wheel off the ground I'd have someone else do the cam swap.