Defendant asserts error for that Judge Hasty failed to make a finding as to the good faith of the defendant in changing from the active practice of dentistry to a student and thereby reducing his income. The defendant asserts that if this change was brought about in good faith, then a change of condition justifying a modification of the previous judgment was established. The defendant made no request of Judge Hasty in this regard, and in the absence of such a request it was not error not to make a finding as to the good or bad faith of the defendant in changing his occupation. The defendant further asserts as error the failure of Judge Hasty to make a finding with regard to whether the plaintiff’s employment subsequent to the February 1969 judgment constituted such a change of circumstances as to afford relief to the defendant and justify a reduction in the payments by the defendant for the support of his children. Again, the defendant failed to request such a finding when he had ample opportunity to do so. “The primary obligation for support of a minor child rests upon the father.” Williams v. Williams, 261 N.C. 48, 134 S.E. 2d 227 (1963).

When the defendant moved that the previous judgment be modified, he assumed the burden of showing that circumstances had changed between the time of the judgment and the time of the hearing upon his motion. The welfare of the children is the “polar star” in the matters of custody and maintenance, yet common sense and common justice dictate that the ultimate object in such matters is to secure support commensurate with the needs of the children and the ability of the father to meet the needs. Crosby v. Crosby, 272 N.C. 235, 158 S.E. 2d 77 (1967).

The defendant had the burden of establishing the change of conditions. The defendant relies on Nelson v. Nelson, 225 Ore. 257, 357 P. 2d 536, 89 A.L.R. 2d 1 (1960). In that case it is stated:

“The sole question presented on appeal is the validity of the court’s assumption that such a voluntary change in position precludes a modification of a support decree.”

*670In the instant case, the defendant fails to establish that Judge Hasty, in refusing to modify the previous judgment, acted on an assumption that the defendant’s voluntary change in position precluded such a modification. Judge Hasty found “that the defendant has not shown substantial change in his earnings (sic) capacity, substantial change in the amount of support required by his children, nor any other substantial change of condition such as would support the conclusion that the best interests of the children of the parties require modification of the Consent Judgment of February 4, 1969, by reduction of child support provision of the said judgment.”

The findings of Judge Hasty were supported by the evidence and will not be disturbed on appeal. Allen v. Allen, 7 N.C. App. 555, 173 S.E. 2d 10 (1970).

Affirmed.