Saw won't cut straight line & Ideal blades for MDF

[curryd]

I have a Delta 40-601 Saw, and am having a heck of a time cutting straight lines. I can be going straight for a few inches, and then all of a sudden it will start to change course, making straight lines a real challenge. I understand all saw's cut a little off center, but changing course in the middle of a cut?

The most recent experience with this was in a 3/4" piece of MDF, using a brand new #3 Flying Dutchman ultimate scroll reverse.

The obvious solution would be that I am using the wrong blade, but I've tried lots of blades, and they all cut very hard and slow. What blades would you recommend for MDF?

[dgman]

Hey curryd, First of all welcome to the forum!
For 3/4" material I would use a #5 or a #7. I don't cut mdf so I don't know what kind of blade to use, But I would try a FD UR. Make sure you have proper tension on the blade. The tighter the better. Most blades have a bur on the right side of the blade so the blade will want to cut faster on the right side. So you have to constantly correct for this drift. FD mike said it best, If your driving in a strait line you still have to move the wheel left and right to go strait. So you will find you will have to constantly correct you cut. This is normal. With practice this will become instinctual. So practice, practice, practice!

[julief]

Hey CurryD, Welcome from Texas.  It sounds like you might be losing tension.  I also would move up to a #5 on 3/4" stock.  Straight lines are tough.  All you can do is practice.  Periodically check to make sure your tension is still good.

[Rapid Roger]

My answer is......MDF is 80% glue and glue is DEATH on scroll blades so, what is happening is...Your blades are getting dull in about 3" of cutting and wondering around in the material (and probably getting VERY hot too) so they wont track well. I'll bet if you do the same cut in solid wood, it will be much easier.
Even plywood has alot of glue in it but, nothing like MDF has. The thicker ply naturally has more layers of glue than the thinner stuff like 1/2" or less so, it is not quite as noticable.

Rog

[GrayBeard]

For the 3/4" MDF I use a #7 Polar blade from Flying Dutchman sold by Mike!

Best tracking blade type I have found for the longer straight cuts.

That is MY method... yours may be different but I like the Polar series for the simple reason that for ME they are easier to control on long cuts.



GrayBeard

[curryd]

Thank you everyone for the response. It sounds like it's an operator problem rather than the saw. I'll try a heavier Polar blade and get a few more hours with the straight lines. Or just toss the junk material and use real wood.

[GrayBeard]

MDF is murder on blades and the dust will choke you! Use a mask!

Practice, tighten tension and take your time!

GrayBeard

[tux_linux]

Switch to plywood, it's so much better. I tried MDF too, but didn't like it.
Plywood is a bit more expensive, but the comfort while sawing is worth the effort.

I check my local hardware store regularly, they offer the oddment at their sawing service pretty cheap (mostly 50-70% off).

regards
Torsten

[julief]

Also, check the cull bin at the Home Depot.  You can get some pretty good buys for basically nothing.  I just picked up 6 - 1X12X8 Poplar boards for $4.01 each. (They are normally 38.97 each)  You never know what you will find in the cull bin.

[frankorona]

▼

Hello, I say that my works are mostly made with MDF of different caliber, wider than I used was 18 mm.
I made that desicion because wood fine here in Mexico costs a lot of money the pine is of poor quality, you fight with him for being a hard material such as stone, so much so that makes you want to throw everything out the window machine.
The advice I can give is to check the voltage of your saw.
Czech in the blog, has your program you can download to hear the calibration of your saw.
Another is the practice, and understand my jig is third world, it is not many good quality but it works well when you learn to use it.
Remember that each machine works differently and if you feel you were used to another change, but bear with the MDF isa very noble material to work with, easy to fix (white glue prepared stir with the surplus of what lijaste, apply to the imperfections, let dry sand again.
When you have more practice I recommend the MDF comes in various wood veneers such as Okoume, Oak, Mahogany and see the difference.
I hope you used this information ... greetings from Puebla, Mexico.

hola: te digo que mis trabajos en su gran mayor?a son realizados con MDF de diferentes calibre, el m?s ancho que he utilizado fu? de 18 mm.
Tom? esa desici?n porque la madera fina  aqu? en M?xico cuesta bastante dinero  el pino es de p?sima calidad, te peleas con ?l por ser un material duro como la piedra, tanto as? que dan ganas de aventar la m?quina  todo por la ventana.
El consejo que te puedo dar es que cheques la tensi?n de tu sierra.
checa en el blog, ha su programa que puedes bajar para oir la calibraci?n de tu sierra.
Otra es la pr?ctica, mi caladora como comprender?s es tercer mundista,no es de mu buena calidad pero funciona bien cuando aprendes a utilizarla.
Recuerda que cada m?quina trabaja diferente y si estabas acostumbrado a otra sientes el cambio, pero ten paciencia el MDF esun material muy noble para trabajar, f?cil de corregir (prepara pegamento blanco  revuelvelo con el sobrante de lo que lijaste, apl?calo en las imperfecciones, d?jalo secar  vuelve a lijar.
Cuando tengas m?s pr?ctica te recomiendo el Mdf que viene enchapado en distintas maderas como son Okume, Roble, Caoba y ver?s la diferencia.
Espero que te haya servido ?sta informaci?n...saludos desde Puebla, M?xico.