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Kurt Krauter in Indy
02-20-2003, 9:41 AM
Good morning all. I have been asked by a friend to come up with a production plan to make some horse jumps for his horse barn. He wants to use cedar posts with some decorative side standards that support the rails for the show horses to jump over.

My question is what would be the best machine to cut the through mortises on the 4x4 cedar posts and should I use a RAS to cut the tenons? My thought was maybe a Powermatic 6x6 (?) mortising machine with a sliding table? He understands that buying a high quality machine is good business.

Any production thoughts would be greatly appreciated!!

Kurt

Ted Shrader
02-20-2003, 10:05 AM
Kurt -

I fully support tool justification for new purchases. In this case I don't think a morticer is what you what. The PM is limited in bit size, so you would still have to make multiple cuts.

How about using the DP with a large bit. Square the corners with a corner chisel. (..or .. with the PM morticer!).

Cut the tenons with the RAS and a dado head, TS (sliding table) w/ dado head, or make a jig/platform for the router w/ spiral bit.

Many methods. What tool do you have, what tool do you want? How many jump stanbds do you have to make?

Good luck,
Ted

Kurt Krauter in Indy
02-20-2003, 10:30 AM
[QUOTE]Originally posted by Ted Shrader
[B]Kurt -



Many methods. What tool do you have, what tool do you want? How many jump stanbds do you have to make?

Ted:
I need to be able to make multiples because he may want to begin mass production of these things if they work well for him. I need to be able to have somebody run these things in a production manner and thought with the moving table on the PM (L-R + F-B) that there would be better repeatability. I also will need to cut the through mortise to accomodate 2x2's fully through.

Also considering as a design option, using rustic logs and the Lee Valley Tenon cutter. At which I will use a DP with LV's aggressive forstner type bit to cut the mortise (I'm sure a jig of some sort will be in order for that operation).

Thanks for the input!!
Kurt

Dennis McDonaugh
02-20-2003, 10:46 AM
You're going to need a large mortise so short of some type of industrial boring machine, a drill press would be your best bet. If you're doing multiple mortises in a single post use multiple drill presses set up side by side. You could mount them permanently and make a jig to bolt to the table. Set the post in the jig and drill each hole. Use a timber frame corner chisel to square up the corners.

D.McDonnel "Mac"
02-20-2003, 12:37 PM
Kurt,

I have a PM719A if that's the PM you are talking about. You can come by and take a look at it any time.

I have got to think a high power horizontal morticer might be a better option. It eliminates the finiky setup needed when using hollow chissels, which is okay in short runs but in production could be a hinderence.

That's my $.02

Kurt Krauter in Indy
02-20-2003, 12:58 PM
[QUOTE]Originally posted by D.McDonnel "Mac"
[B]Kurt,

I have a PM719A if that's the PM you are talking about. You can come by and take a look at it any time.

Thanks for the offer Mac.

I think I will take you up on that. Maybe I could swing by some afternoon or early eve. and take a look and get some engineering advice.

I'd like to bounce some ideas off of you. Let me know when would be a good time (maybe I'll be able to make the Pond Voyage).

Let me know, my time frame is unclear at this point.
Kurt

Lee Schierer
02-20-2003, 1:10 PM
I know very little about jumping horses, but aren't the pieces supposed to be on shelves so the horse can knock them free if he hits them? I think the ones I've seen set in shallow saddle type brackets mounted on the stand upright.

For turning hte ends of those 10' logs, you're going to need a large lathe.

Lee:confused:

Kurt Krauter in Indy
02-20-2003, 1:20 PM
[QUOTE]Originally posted by Lee Schierer
[B]I know very little about jumping horses, but aren't the pieces supposed to be on shelves so the horse can knock them free if he hits them? I think the ones I've seen set in shallow saddle type brackets mounted on the stand upright.

For turning hte ends of those 10' logs, you're going to need a large lathe.

Hi Lee,

The jumps do indeed have what they call jump plates that are hinged "cups" that attach to these standards. The Rails sit in these cups and easily fall off when hit.

What I am trying to build is the decorative standard that needs to be pretty stout to take some of the punishment of the collision but also fairly light weight and of a design that will justify the cost (these horse people live on a different planet than we in terms of what they'll pay for certain equipment).

BTW - will we see you and Sue in Anderson in April??

Kurt

Chris Knight
02-20-2003, 2:14 PM
Kurt,

For this kind of "timber framing" work you need a chain mortiser like this:- http://www.mafell.com/produkte/prod_fraesen_ls103_i.htm

Chris