LumberJocks Woodworking Forum banner

RAS

2K views 17 replies 15 participants last post by  toolie 
#1 · (Edited by Moderator)
I have been given a RAS (haven't seen it yet,but was told it doesn't cut straight,Can that be a adjustment?
My main question is why do people feel these are more dangerous the any other power saw?
Why have I read you shouldn't dado with one?Issues?
 
#2 · (Edited by Moderator)
Not cutting straight…adjustment…you have stumbled on the inherent problem with the tool…look at one and you will see that "tuning" is a task that has to be performed often (blade travel perpendicular to the fence, blade perpendicular to the table, arm swing accurate on the angles, etc. etc.). Those little "quirks" also explain why it is such a versatile tool…when I started making sawdust it was the single large tool I could afford and it served me well, just required a little TLC to make sure I didn't get into those "pinch" situations that could shoot a board backwards into the sheetrock. As for dados, proper set-up would seem to make it the ideal tool because you can see your work…but that goes back to that "tuning" part. And I would never attempt it on short pieces…
 
#3 ·
Them thumbs get lost on cross cutting, ribbing is setting up a rocket launch, I have ribbed a couple times on one, no thanks, cross cutting and miter cuts are the same a s a sliding miter saw, just be aware of your left thumb , keep it out of the cut line.
 
#4 ·
Them thumbs get lost on cross cutting, ribbing is setting up a rocket launch, I have ribbed a couple times on one, no thanks, cross cutting and miter cuts are the same a s a sliding miter saw, just be aware of your left thumb , keep it out of the cut line.

- conifur
There not the same as a sliding miter saw.

You need to give more input on the saw.
 
#5 ·
This really depends on if you are getting a cman ras or an old delta or dewalt.

Once you fill in that blank come back and let us know.

When I did this for cash we used a 16 inch delta Rockwell for all crosscuts. It was a great saw. Dad gave me a cman. It was an anchor. It sucked. I wouldn't drop it on my ex. It really depends.
 
#7 · (Edited by Moderator)
Tell me how cross cutting on a RAS is different then a sliding miter saw?

- conifur
Cross cutting is basically the same, although you will typically be able to cross cut wider material on the RAS. Beyond that, a RAS is much more versatile and can do a lot of things not possible on a miter saw, sliding or otherwise. I have both, and don't plan on getting rid of either one any time soon.

Cheers,
Brad

PS: What is "ribbing"?? Did you mean "ripping"?
 
#8 ·
Jack:You need to give more input on the saw.
My question is more of a general one on the adjustment.I don't know more than I have said about it.Just if the group said there is nothing to adjust then i would expect it will be what it is.but sounds like they are most likely adjustable.
I heard something about RAS's climb?what's that in this term?
And I guessing I'll have to build some kind of table/stand setup and good designs on LJ or online?what search term?
 
#9 · (Edited by Moderator)
Oh.. got off topic :)

There are a lot of different adjustments on a RAS to bring it into alignment.. and the specifics will depend on what saw you have. It starts by ensuring that the table is level to the travel of the carriage. I guess if yours doesn't have a table/stand, then you will need to fabricate something first. Once you get it level and parallel to the table, you go on to square the blade to the fence and perpendicular to the table, adjusting for any heel present, calibrating the scale, etc…

I have never seen a RAS that can't be adjusted, and each has the sequence described in it's manual. You should not have any problem getting it into alignment so it makes perfectly square cuts. And I actually consider the RAS to be one of the safer tools in the shop for most all operations it's capable of (but ripping isn't one - that's why they invented table saws :)

"Climb" is where the blade tries to self-feed, but with the proper blade and good control on the carriage, it isn't really a problem.

Cheers,
Brad

PS: Lots of folks use the RAS for dado cuts… some keep one dedicated for that purpose only.
 
#10 · (Edited by Moderator)
Back to the "frequent" tuning thing…I've had 2 Craftsman saws, and couldn't keep them cutting 90º with any amount of tuning, the design is such that it's very difficult to get them tuned….that said, some guys have very good luck with the early 70's and lder models. But with a Dewalt solid cast arm (I've had 5) or Delta turret arm saw you cna tune them dead nuts, and they hold that tune unless you do something really stupid. The bad rap the RAS has is due to (IMHO) the junk that Sears sold and labeled as the only tool you need in the shop. As for safety, (again, IMHO) it's no more dangerous than any other tool in the shop and a lot more useful than most. They are extremely useful and can earn their keep in any shop.
 
#11 ·
I have a 29 year old craftsman RAS. I use it on almost every project I do. Before I start a project, I always tune it up. Usually doesn't require much. You have to make sure its perpendicular to your back fence, and keep the travel arm lubed> Other than that I think its great. I read all the criticism on it, but for me it does the job.
 
#12 ·
I bought one in "88" and I still have it and use it a lot. I do not usually rip with it although I have long ago. I use a table saw for that. I don't really see a time that I will get rid of it unless I am not able to work.

Only had one bad trip with it and it was my own fault. I was in a hurry and wanted to cut a slight angle on a piece and didn't want to bother with changing the angle of the arm. So, I held the piece at a slight angle very tightly thinking I could make one cut that way without any trouble. NOT SO! The saw blade pulled the wood back and my finger was in between the fence and the wood because I was holding the wood with my hand. Talk about a blood blister! It did no permanent harm but taught me a life long lesson.

Get the manual and pay attention to it and they are a great tool. larry
 
#13 ·
My old DeWalt is dead-nuts straight, and with a negative hook cross-cut saw on it, it cuts smoothly with minimal climb. Since setting it up, I've not really touched my table saw sled or shooting board.

The capacity on a RAS table is a lot more than a sliding miter saw. Going from 90 to 45 degree cuts and back is super simple. Dado cuts are an option. Raising the blade just means cranking the handle.
 
#14 ·
I'm pretty much in the Ian camp - Old DeWalt that is straight, and stays there with very little coaching. I don't have the negative hook blade, so there's a bit a care to be taken to guide the saw across the stuff being cut. I like using it for dado cuts because I can see what I'm doing. And I rip with my RAS more often than most, it seems. No SCMS in inventory, doubt I'll every get one. The heavy Craftsman mitersaw (chop saw) is used for framing.

Did you find out what you're getting yet? Did I miss that? Need pics when the time comes!
 
#15 · (Edited by Moderator)
Have a look at PaSs post on dado blades and RAS, and as for accuracy check out my RAD review.

Basically the more moving parts the more cumulative errors add up, all of which mind you can be accounted for in the job.

I do not have a RAS but thats not for any particular reason other than usage for it, I do however have a RAD which is a bit of a rareity in the wood shop, so to each his own!
 
#16 ·
RAS's are thought to be more dangerous because the saw tends to "self feed" which can startle the operator when the blade suddenly moves toward you. The reason for that is; most people put a regular blade intended for table saws on the RAS. You need to use a blade with NEGATIVE rake. Table saws use blades with POSITIVE rake. The same reason dado blades are not used. They are not made with negative rake; at least I haven't seen one. I suppose they could be special ordered.

BTW, sliding miter saws require negative rake blades, while non-sliding miter saws can use positive rake blades.
 
#17 · (Edited by Moderator)
None of these answers seem to have addressed one of the questions the OP asked. The RAS and SCMS differ in some significant ways. With the SCMS, you push the blade through the work. With the RAS, you pull the blade through the work.

The RAS lets you set depth of cut, such as for rabbeting. The SCMS does not allow this kind of adjustment, except as a way of making sure the blade cuts all the way through, and even then it is an imprecise adjustment, and not something you are ever likely to do.

I do not agree that a SCMS requires a negative hook blade. The reason for this recommendation for a RAS is that it helps control the tendency for the blade to climb and rush toward you. Ryobi actually made a model of RAS that had a mechanism to control this tendency. I have no idea how this worked, nor how well it worked.

Ripping on a RAS has dangerous potential in that you must not feed the board in from the wrong direction. Always feed the work toward the carbide. If you feed from the wrong end, the saw will grab the board and shoot it like a missile. My uncle made a hole in his garage wall by doing this. I always hoped to see McGyver use this as a way to escape from a shop he was locked in. The closest he ever came was to use a table saw to shoot some little blocks of wood (cut offs) at some bad guys. Didn't hurt them, though, just annoyed them.

I agree that it's best to avoid Craftsman RAS. Dewalt and Delta/Rockwell made much more robust machines.
 
#18 ·
None of these answers seem to have addressed one of the questions the OP asked. The RAS and SCMS differ in some significant ways. With the SCMS, you push the blade through the work. With the RAS, you pull the blade through the work.

The RAS lets you set depth of cut, such as for rabbeting. The SCMS does not allow this kind of adjustment, except as a way of making sure the blade cuts all the way through, and even then it is an imprecise adjustment, and not something you are ever likely to do.

I do not agree that a SCMS requires a negative hook blade. The reason for this recommendation for a RAS is that it helps control the tendency for the blade to climb and rush toward you. Ryobi actually made a model of RAS that had a mechanism to control this tendency. I have no idea how this worked, nor how well it worked.

Ripping on a RAS has dangerous potential in that you must not feed the board in from the wrong direction. Always feed the work toward the carbide. If you feed from the wrong end, the saw will grab the board and shoot it like a missile. My uncle made a hole in his garage wall by doing this. I always hoped to see McGyver use this as a way to escape from a shop he was locked in. The closest he ever came was to use a table saw to shoot some little blocks of wood (cut offs) at some bad guys. Didn t hurt them, though, just annoyed them.

I agree that it s best to avoid Craftsman RAS. Dewalt and Delta/Rockwell made much more robust machines.

- runswithscissors
While I would agree with the c-man RAS comment for newer ( bolted 2 piece aluminum column support) RASs, the ones from the 50s to mid 70s with CI clomn supports can be made quite serviceable and can usually be had for < $100. Bear in mind that they don't like to be moved around and I reserve mine for 90* cuts only.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top